Many great literary works are compilations of shorter tales, set in a framing story. Among the best known are One Thousand and One Nights and Sanskrit epics including Mahabharata. Among the most enduring in post-classical Europe is Boccaccio’s Decameron, whose stories have also proved popular with painters. Over the next couple of months I’m going to summarise those that have been well depicted in this new series, and show those paintings.

Despite the number of scholars who have researched Giovanni Boccaccio’s life over the last seven hundred years, much of it remains vague. He was either born in Florence, or perhaps near the village of Certaldo to the south-west of the city. His father worked for the Bardi bank, but he is thought to have been illegitimate and his mother hasn’t been identified.

We do know that he was born on 16 June 1313, and while still a child his father married a woman from a rich family, then moved to Naples. At the time, that was a major cultural centre, and as a young man Boccaccio immersed himself in that. His father expected him to become a banker, and Giovanni started work as an apprentice in his father’s bank in the city.

Boccaccio had no interest in banking though, and persuaded his father to let him study canon (ecclesiastical) law at the city’s university. When he was in his twenties, his father introduced him to the Neapolitan court and cultural circles around Robert the Wise, King of Naples. Among Boccaccio’s most important influences at this time was the scholar Paolo da Perugia, who had amassed much information about classical myths. Boccaccio became a scholar, particularly of the classical world, a writer rather than an ecclesiastical lawyer, and his future started to crystallise when he wrote his first poetry.

His early works became sources for Chaucer’s Troilus and Criseyde (Troilus and Cressida), and the Knight’s Tale.

Boccaccio left Naples in 1341, as tensions were growing between its king and the city-state of Florence, and returned to live mainly in Florence, although he also spent time in Ravenna. He developed great admiration for the work of Dante Alighieri, who had died in Ravenna twenty years earlier, and the great poet Francesco Petrarca (Petrarch) (1304-1374), whom he regarded as his teacher.

Giorgio Vasari is now more famous for his biographies of the important painters of the Renaissance and earlier, but was also an accomplished artist himself. His tribute to some of the greatest writers of the period is Six Tuscan Poets from 1544. From left to right, I believe these to be Dante Alighieri, Francesco Petrarca (Petrarch), Guido Cavalcanti, Giovanni Boccaccio, Cino da Pistoia, and Guittone d’Arezzo.

William Bell Scott’s undated painting of Boccaccio’s Visit to Dante’s Daughter shows the writer paying indirect homage to his illustrious predecessor. Boccaccio wrote the first biography of Dante, at about the same time he was writing the Decameron.

During the 1340s Boccaccio appears to have been developing the idea of a book in which seven characters take it in turns to tell stories. When the Black Death struck Florence in 1348, killing Boccaccio’s stepmother, this provided him with its framing story. He was already building his collection of tales to form the bulk of the book, and it’s thought he started its writing shortly after the Black Death. What is more doubtful is whether Boccaccio was living in Florence when the epidemic struck. However, as it raged through the whole of Tuscany in that year, hardly sparing a village, it’s most unlikely that he didn’t observe its effects somewhere, perhaps in Ravenna.

In 1349, Boccaccio’s father died, leaving Giovanni as the head of the household. In spite of that, he pressed on and had largely completed the first version in 1352. He revised it in 1370-71, and ever since it has been widely read, translated into all major languages, and its stories have inspired many works of art.

Egide Charles Gustave Wappers painted Boccaccio Reading from the Decameron to Queen Johanna of Naples in 1849. Queen Joanna I of Naples (1328-1382) had a reputation that was more than controversial, but Boccaccio was a supporter, and wrote a complementary account in his collection of biographies of famous women, De Mulieribus Claris (On Famous Women).

This miniature by the Master of 1482 and Follower conflates Boccaccio, the Black Death in Florence, and the framing story of the Decameron: Giovanni Boccaccio and Florentines who have Fled from the Plague was painted in about 1485 on vellum, in what must have been one of its first illustrated editions.

The Decameron opens with a description of the horrific conditions and events that overwhelmed Florence when the Black Death struck, then takes us to a group of seven young women who are sheltering in one of its great churches. They decide to leave the city rather than waiting amid its rising pile of corpses, to spend some time in the country nearby. They take some servants and three young men to accompany them there.

Once settled in an abandoned mansion, the ten decide that one of the means they will use to pass their self-imposed exile is to tell one another stories. Over the next two weeks, each tells one story on every weekday, delivering a total of one hundred, hence the title of the book.

Raffaello Sorbi show the group of ten during one of the story-telling sessions in The Decameron from 1876, with the city of Florence in the distance.

Salvatore Postiglione’s undated, ornate and almost illustrative Scene of the Narration of the Decameron is unusual for omitting one of the seven young women, but links visually to their other musical and craft activities.

Relatively few of the hundred tales in the Decameron have been committed to paint. Some are little more than brief fables, or what used to be known as shaggy dog stories. Others are more lengthy novellas with intricate twisting plots. But many have been painted from the Renaissance until well into the twentieth century, and were particularly popular with the Pre-Raphaelites.

The tale of Griselda has cropped up in folk stories across Europe before it was told as the final tale (Day 10, Story 10) of the Decameron. It was then taken up by Chaucer in the Clerk’s Tale, and by Charles Perrault. Francesco Pesellino painted it in this Scene from the Life of the Griseldis from around 1450.

One of the most significant series of paintings of the Decameron is Sandro Botticelli’s Story of Nastagio Degli Onesti, of which this is the first. Boccaccio includes this horrific tale as the eighth story on Day 5, shown by Botticelli in four panels that were commissioned as a wedding gift for a couple whose marriage was partly arranged by Lorenzo the Magnificent (Lorenzo de’ Medici), ruler of the Florentine Republic in the late fifteenth century, and Botticelli’s patron.

One of the earliest and greatest examples of Pre-Raphaelite painting is John Everett Millais’ Isabella (Lorenzo and Isabella) from 1848-49. When exhibited at the Royal Academy in 1849, it was accompanied by lines from John Keats’ poem Isabella or the Pot of Basil, referring to the story of the ill-fated love of Lisabetta for Lorenzo, the fifth told on Day 4.

Later in the nineteenth century, Marie Spartali Stillman painted The Enchanted Garden of Messer Ansaldo (1889), showing a scene from the fifth story of Day Ten. This was also painted by John William Waterhouse in 1916-17.

Perhaps the most popular of all the stories in the Decameron with visual artists has been the romance of Cymon and Iphigenia, here shown in Frederic, Lord Leighton’s luscious and languid painting from 1884.

I hope that you will join me in looking at many more wonderful paintings exploring Boccaccio’s stories from the Decameron in the coming weeks.

I hope that you enjoyed Saturday’s Mac Riddles, episode 334. Here are my solutions to them.

1: First fruit at the top left since 1984.

Click for a solution

 Apple menu

First (it’s the first item in the menu bar) fruit (an apple) at the top left (where it is) since 1984 (it has been there since the first Mac).

2: Line of people uppermost for new documents and saving.

Click for a solution

File menu

Line of people (a file) uppermost (it’s in the menu bar) for new documents and saving (it contains the New and Save commands).

3: Formal inspection to customise window from above.

Click for a solution

View menu

Formal inspection (a view) to customise window (what commands in this menu do) from above (it’s also in the menu bar).

The common factor

Click for a solution

They are three of the four standard menus in the Mac since its release in 1984. The fourth is the Edit menu.

I look forward to your putting alternative cases.

Websites come and go, and although the Internet Archive’s Wayback Machine provides a unique service by preserving so many, saving your own copies of pages remains important to many of us. This article looks at how you can do that using Safari 26, the current release for supported versions of macOS. If you want to explore the pages saved in the Wayback Machine, then its Safari extension is available free in the App Store.

Safari now offers the following five options for saving a page:

• File/Save As…/Page Source to save it as an HTML source file (169 KB).
• File/Save As…/Web Archive to save it as a Webarchive file (2.7 MB).
• File/Save As…/PNG to save it as a PNG image (43.5 MB).
• File/Export As PDF… to save it as a PDF file, in display format (31.6 MB).
• File/Print…/Save as PDF to save it as a PDF file, in print format (28.1 MB).

Sizes given are those for a test page with plenty of images from here.

Page source

This is the smallest and least complete version of the five, as it contains just the HTML source of the page, omitting all linked and similar generated content. For relatively plain pages containing text exclusively, this can be useful. The saved file can be opened in Safari or another browser, and so long as none of the linked content is missing or changed, you should see the original content reconstituted, but in a flattened layout without columns or styling. This is unlikely to be suitable as a lasting record, although it’s by far the most compact at 169 KB for the test page.

Web Archive

This saves to a single opaque webarchive file containing the entire contents of the page, including embedded images and other content, but not linked downloadable files. Although this format is peculiar to Safari, it has had limited support by some other apps, but I can’t find any other current software that can give access to its contents.

A webarchive file is a (binary) property list written as a serialisation of the web page content in Safari, in a series of WebResource objects. For example, a JPEG image would consist of:

• WebResourceData in Base-64 containing the image data;
• WebResourceMIMEType of image/jpeg;
• WebResourceResponse in Base-64 data;
• WebResourceURL containing the URL to the file.

Although in theory it should be possible to recover some of its contents separately, in practice that isn’t available at present. In the past access has been supported by the macOS API, but all those calls to work with Webarchive files are now marked as being deprecated by Apple. Current API support is limited to writing but not reading them from WKWebView from macOS 11 onwards, and there’s no sign of that being extended.

Webarchive format has changed over time, and compatibility with different versions of Safari is unpredictable. When testing in virtual machines, Safari 18.6 proved incapable of opening any webarchive test file, including its own, while Safari 26.0 and 26.1 loaded webarchives written by Safari 18.6, 26.0 and 26.1. There has also been a long history of problems reported with webarchive files. Recent versions of macOS can display QuickLook thumbnails and previews of webarchives, although thumbnails aren’t particularly faithful to their contents.

Although webarchives should contain embedded images shown in the original page, those appear to be saved at the resolution they’re displayed in. This helps limit the size of files; in the case of the test page used here, that required 2.7 MB, around 10% of the size of a PDF, making them the most efficient option apart from plain HTML.

When they work, Safari Web Archives can provide excellent snapshots of web pages, but longer-term compatibility concerns make them unsuitable for archival use.

PNG

Saving the page to a PNG graphics file is a relatively new option in Safari. For the example page, that generates a 2,622 x 32,364 pixel image of 43.5 MB size, making it the largest of all.

The PNG image is a faithful replica of the page as viewed, although it can be affected by lazy loading (see below). Disappointingly, its text contents don’t appear to be accessible to Live Text, limiting its usefulness.

PDF

Safari provides two routes for turning a webpage into a PDF document: directly using the Export As PDF… menu command, and indirectly via the Print… command then saving as PDF from the Print dialog. The results are different.

Exporting as PDF creates a document in which the entire web page is on a single PDF page, although it can spill over to one or two additional pages. The advantage of this is that the PDF is one continuous page without any breaks, and is a faithful representation of what you see in your browser, complete with its original layout and frames. The disadvantage is that this won’t print at all well, imposing page breaks in the most awkward of places. Very long pages can also prove ungainly, and difficult to manipulate in PDF utilities. The example page was 31.6 MB in size.

Printing to PDF breaks up the web page into printable pages, and splits up frames. What you end up with isn’t what you see online, but could at a push be reassembled into something close to the original. That isn’t too bad when the placement of frames isn’t important to their reading, but if two adjacent columns need to appear next to one another, this layout is likely to disappoint. It is the best, though, for printing, with headers and footers and page numbering as well. The example page was slightly smaller than the single-page version, at 28.1 MB.

While PDF is one of the preferred formats for archiving laid-out documents, it’s worth bearing in mind that standard macOS PDF isn’t compliant with any of the PDF/A standards for archival documents. You’d need a high-end PDF editor such as Adobe’s Acrobat (Pro) CC to prepare and save to any of those.

Despite being ancient and inefficient, PDF normally does a good job of preserving the original format and layout. Text content is preserved, if laid out erratically, making it ideal for content search. Thus, either of the PDF options is best-suited for archiving web pages from Safari.

Lazy loading

Recent versions of Safari appear to load pages lazily, only inserting some images and other included content when scrolled. If you save that page to PNG or PDF without scrolling to the end of the page, the resulting file may skip those images that haven’t yet been loaded. Check the file when it has been saved to ensure that all enclosures have been captured successfully.

Conclusions

• Save As…/Page Source is of limited use, mainly for text-only pages without embedded content.
• Save As…/Web Archive can be excellent for day-to-day use, being complete and faithful, but isn’t an open standard and can prove fragile. It’s therefore not recommended for critical or archival use.
• Save As…/PNG is of limited use, as its images are largest and their content least accessible.
• Export As PDF… is excellent for day-to-day use, complete and faithful, but for serious archival use needs to be converted to comply with an archival standard in the PDF/A series.
• Print…/Save as PDF is an alternative more suitable if you want to print the document out.
• Before saving to PDF or PNG ensure you scroll through the whole page, then afterwards check the saved document contains everything it should.

Making a highly successful career for yourself as a woman artist in the Renaissance was an extraordinary if not unique feat. It’s one of the many accomplishments of Sofonisba Anguissola (c 1532-1625), who also managed to survive the ravages of infectious disease, and died in her early nineties, four centuries ago today.

Even more unusually, she wasn’t born into an artistic family, but into minor nobility in Cremona, Lombardy, Italy. The oldest of Amilcare Anguissola’s seven children, the family claimed ancestry going back to ancient Carthage. Amilcare and his wife Bianca educated and encouraged their daughters to develop their abilities, resulting in four of their six girls becoming painters, but it was only Sofonisba who persisted long enough to make a career of her art.

When she was fourteen, Sofonisba went to study in Bernardino Campi’s workshop, then to Bernardino Gatti’s. She probably completed her training in about 1553, but by then was already painting outstanding works in oils.

One of her earliest surviving paintings is also one of her most remarkable and ingenious, this Self-portrait with Bernardino Campi, painted in 1550 when she was just eighteen. This double portrait is fascinating in her depiction of two left hands on the portrait that Campi is shown working on: one reaches up to meet his right hand, holding a brush, and the other holds her own brushes.

Only five years later she transformed Renaissance portraiture with her superb The Chess Game (1555), showing her sisters playing chess, with their mother (probably) making an appearance at the right edge. Her sisters Lucia, Minerva and Europa are shown dressed in their finest, but the informality of their poses and expressions is striking, and innovative in portraits at that time. Her attention to detail in clothing and on the table is also notable, and perhaps more characteristic of the Northern Renaissance. Her other portraits are just as finely detailed.

In addition to painting her family, she also completed a series of self-portraits in her early career, including this Self-portrait from 1554, when she was twenty-two. The contrast with the fine dress and relaxed informality of her family portraits is interesting, and may reflect her almost austere devotion to her art.

A couple of years later, Self-portrait at the Easel (1556) shows her working on an exquisite devotional painting which may have been of the Virgin and Child, showing the deep relationship between a mother and her infant, and another painting within a painting.

This small undated Self-portrait on a tondo is no more relaxed.

Her Portrait of the Artist’s Family of 1557-58 maintains her style of informality in poses, although its composition is more typical of the day. This shows her younger sister Minerva, father Amilcare, and young brother Asdrubale, with a fantasy landscape of classical ruins and the rising towers of distant castles, receding to a dramatic mountain.

She stayed in Rome in 1554, where she met Michelangelo and several other artists. Michelangelo seems to have mentored her for a while. She became an established portraitist, and in 1559 was invited by King Philip II of Spain to teach painting to his wife, the young Queen Elisabeth of Valois. Anguissola painted many important portraits while in Philip’s court, and prospered as a result.

This fine Portrait of Prince Alessandro Farnese from about 1560 has been attributed to her. The prince, who later became Duke of Parma and Piacenza, lived from 1545-1592, and this portrait conforms to more standard practice.

Her Portrait of Anna of Austria of 1573 was one of her more important commissions. Anna (1549-1580) was the fourth wife of her uncle, King Philip II of Spain, and the daughter of the Holy Roman Emperor Maximilian II. She married the king in 1570 following the death of Queen Elisabeth of Valois, who had been Anguissola’s pupil. Among Anna’s other portrait painters was Giuseppe Arcimboldo, later famous for his unique ‘vegetable’ portraits.

Although she had married a noble in 1571, she continued to paint professionally, and the couple moved to Paternò, near Catania on the east coast of Sicily. Her first husband died eight years later, and in 1584 she married again, moving to Genoa.

This unusual Portrait of Julius Caesar Aged 14 from about 1586 shows, according to its inscription, the famous Roman emperor, who lived from 100-44 BCE. She has approached it as another of her informal portraits rather than as a history painting.

Her religious paintings broke new ground in the intimacy with which she shows family scenes, as in The Holy Family with Saints Anne and John the Baptist (1592).

She taught and provided advice to other painters throughout her later career, and in 1624 was visited by the young Anthony van Dyck. Her sight was failing by that time, but she was still able to give him good advice. Finally, Anguissola moved to Palermo, where she died at the age of 92 or 93 in 1625. She had no children, but left a generation of artists who had benefitted from her innovation and influence. Among those directly inspired by her example and work was Lavinia Fontana. Over two centuries later, Ella Sophonisba Hergesheimer pursued her painting career bearing Anguissola’s name.

Reference

Wikipedia.

In the early years of this blog, I used to keep track of some of the more serious bugs in macOS. As that developed into what would have occupied me full-time, I’ve cut back to try to cover some of the most significant. What has surprised me with macOS 26.1 is the sudden rush of new bugs in an update that’s normally expected to fix more than it creates. To consider what might have gone wrong, here’s an overview of those I’ve been investigating so far.

macOS virtualisation (new in 26.1)

A macOS 26.1 guest assigns itself a serial number of zero for the VM, whether the VM has been installed from the 26.1 IPSW image file, or updated from a previous version of macOS. This results in features that rely on the VM’s serial number to fail, the most important being access to iCloud.

Further details.

Virtualisation is exceedingly complicated, and has suffered some previous accidents, such as the inability of M4 hosts running macOS 15.1 to virtualise guests with macOS earlier than 13.4. Although it’s easy to claim that better testing should detect these problems, the number of combinations of host Mac and macOS, and guest macOS increases their risk. Perhaps Apple should actively encourage third-party beta-testing in VMs.

Accessibility (new in 26.1)

macOS 26.1 introduces a new Appearance setting for Liquid Glass, but Apple hasn’t mentioned any change to the existing Reduce Transparency setting in Accessibility. However, that setting in 26.1 no longer disables Liquid Glass effects in sidebars and toolbars as it does in 26.0. User documentation for 26.1 is identical to that in macOS 15:
Make transparent items solid
Some windows and areas of the desktop, such as the Dock and menu bar, appear transparent by default. You can turn these transparent areas a solid grey to make it easier to distinguish them from the background.

This can be seen in the following screenshots.

This is 26.0 without Reduce Transparency.

This is 26.0 with Reduce Transparency turned on. Both the navigation sidebar and the window toolbar are completely opaque, and their contents are fully readable as a result.

This is 26.1 with Reduce Transparency turned on. Although the tools themselves are on opaque backgrounds, other areas remain partially transparent, and the toolbar in particular is visually cluttered and impairs accessibility.

Although this could be claimed to be intentional on Apple’s part, one visual feature that now appears when Reduce Transparency is turned on is the unreadable mess at the top of the System Settings window, where its search box overlays scrolling content in that sidebar.

If that’s intentional on Apple’s part, then macOS 26.1 is unsuitable for users with most forms of visual impairment, and many without.

Finder (new in 26.1)

In some Finder views, such as Column View, selecting an item at the left displays that item’s thumbnail and associated metadata. Below those are a selection of tools offering Finder services, such as Rotate Left, Markup, and more. Those are non-functional in 26.1, and if you want to use any of those services, you’ll have to use an alternative method, such as the contextual menu.

Further details.

This is a strange bug, as it doesn’t occur in macOS VMs, suggesting there’s something more complicated going on. However, it’s also obvious, easy to test, and should never have survived into a release version of macOS.

Clock (macOS 15 and 26)

In macOS 15 and 26, including 26.1, the Clock app offers Timers that are implemented using the mobiletimerd service. The latter appears to hoard every past timer in its property list until that grows too large for the service to run, following which the feature fails to function.

Further details.

According to Apple Support, an earlier bug in the mobiletimerd property list was fixed in macOS Sequoia. However, Apple is apparently unaware of the current problem. The current behaviour of mobiletimerd appears to be the result of poor design: if a service keeps adding more items to its property list, that will grow unconstrained, and sooner or later will cause this problem. It’s possible that fixing the previous bug may have resulted in the introduction of a new bug. Either way, this should have been detected long before it was released to the public.

Spotlight indexing (macOS 10.14 and later)

Since macOS Mojave, plain text files starting with certain characters don’t have their content indexed. Those files are correctly assigned to have their contents indexed by the macOS RichText mdimporter, according to their UTI. However, at the start of content indexing the text is checked for its ‘magic’ content. Those files that aren’t indexed because their opening bytes are recognised as being those of other types, and indexing is abandoned because of an error in the mdimporter. Examples of opening UTF-8 characters that can trigger this include the uncommon LG and HPA, and more common Draw.

Further details.

This is the strangest bug among these, as the Rich Text mdimporter is supposed to index content according to the UTI of the file being indexed, which is being recognised correctly. There should be no need to perform another less reliable method of file type recognition using the ‘magic’ rules that is then causing content indexing to fail. That appears to have been introduced over seven years ago, but never tested adequately against a suitable search corpus.

The same mdimporter had suffered another bug that failed to index the content of any Rich Text file that was also undetected for over six months in 2020-21. Without thorough testing of mdimporters, further bugs are likely to occur in release code and remain undetected for long periods.

Conclusions

• Of these five serious bugs in macOS 26.1, three are new to 26.1, one inherited from macOS 15, and one dates back seven years to macOS 10.14.
• At least two of the five appear to have been introduced when trying to fix earlier bugs.
• All five should have become obvious during testing, and none should have remained in any public release of macOS.
• Both of the bugs that were inherited from macOS 15 appear to reflect flawed design.
• Only one of the bugs, that in virtualisation, is noted in Apple’s developer release notes for 26.1, and that wasn’t carried forward to its release notes for users.

Acknowledgements

I’m very grateful to Rich Trouton, Michele, Paul, Jürgen, Drew, aldous and others who have provided invaluable information about these bugs.

Tomorrow, 16 November, marks the four-hundredth anniversary of the death of one of the first great women painters, Sofonisba Anguissola. In preparation, this article looks at four of those who followed in her brushstrokes, and succeeded in a world so dominated by men.

Lavinia Fontana was a precocious painter in the late sixteenth century, the only child of the successful artist Prospero Fontana. With no son to take the family workshop on, it was a relief to her father that she showed strong artistic ability at an early age; so early that by the time she was thirteen, she may have been generating much of the family’s income.

Her paintings provide unusual insights into contemporary family life, as in her Portrait of a Newborn in a Cradle (c 1583). This is clearly a child of a rich family, wearing a string of pearls in their ornate crib.

Fontana set a tradition that successful women painters should make several works showing Judith with the Head of Holofernes. This version, from 1600, avoids gore and puts the severed head discreetly in half-light, while Judith brandishes the sword with pride, and her maid appears delighted. Her use of rich colours and chiaroscuro were advanced for painting in Bologna at the time.

Her workshop in Bologna was successful and prosperous, but ultimate recognition came in 1603, when Pope Clement VIII invited her to move to Rome. She quickly acquired powerful patronage, painted a portrait of Pope Paul V and became his court portraitist, and was even awarded a bronze medallion made for her by Casone in 1611.

When in Rome, she painted this remarkable family Portrait of Bianca degli Utili Maselli with six of her children (1604-5), showing this wife who died within a year of its completion, five of her sons, and her daughter Verginia. As in many of her portraits, the lapdog was a sign of fidelity, and her depiction of clothing exquisite.

Fontana died in Rome in 1614, leaving the largest oeuvre of any woman painter prior to 1700. Unlike the few who had gone before her, she had succeeded at the highest level in a range of different genres, including mythology, religious works (with some large-scale altarpieces), and portraiture.

While she was painting for the Pope in Rome, in northern Europe still life painting was developing rapidly, thanks to the quiet brilliance of Clara Peeters. We don’t even know when she was born, but she seems to have trained in Antwerp, then pursued her career successfully in the Dutch Republic to the north. She’s thought to have been internationally successful by 1611, when at least four of her paintings were sold to Spain. Her last reliably dated works are from 1621, although there are a few attributed to her from later. No one knows whether she stopped painting when she married, or when she died.

Her Still Life of Fish and a Candlestick is one of the earliest and most accomplished paintings of the fruits de mer, which were to find favour with William Merritt Chase nearly three centuries later.

The following year, her still life with Flowers and Gold Cups of Honour (1612) reveals multiple miniature self-portraits reflected in the gold cup at the right. These are shown more clearly in the detail below.

Her short career overlapped with that of the most famous of all the early women painters, Artemisia Gentileschi. She was the eldest child of the renowned Tuscan painter Orazio Gentileschi, learned to draw at an early age, and soon worked in her father’s workshop. Her father was strongly influenced by the work and friendship of Caravaggio, which in turn was an early influence on Artemisia.

She was taught by Agostino Tassi, when he was working with her father on murals in a palace in Rome, when Artemisia was already painting her own works in oils. Tassi raped Artemisia, and continued to have sexual relations with her in the expectation that they would marry. Her father pressed charges against Tassi, who was eventually convicted after a long trial that was profoundly traumatic physically, mentally, and emotionally for Artemisia.

Her father arranged for her marriage to a modest Florentine painter, and the couple moved to Florence where she started receiving commissions. They worked there between 1614 and 1620, when she became the first woman ever to be accepted into the Accademia delle Arti del Disegno. She enjoyed good relationships with other prominent artists and intellectuals, including Galileo Galilei. In 1618 the only one of her four children to survive into adult life was born, Prudentia, who also became a painter. However, in 1621 she separated from her husband and moved back to Rome. This didn’t prove a success, so she moved to Venice, and on to Naples in 1630.

Her first painting of Susanna and the Elders from 1610 remains her best-known, and with Tintoretto’s is one of its canonical depictions. Gone are the decorations, symbols, and diversions of earlier artists, in favour of a close-up of the three actors at the crucial moment that the elders tell Susanna of their ‘generous offer’. They’re as thick as thieves, one whispering into the ear of the other, who holds his left hand to his mouth as he commits his crime. Susanna is naked, distressed, and her arms are trying to fend the elders off. Her face tells of her pain and refusal to succumb to their blackmail.

She is most famous for her paintings of Judith Slaying Holofernes, her first version being painted at about the same time as her rape and Tassi’s subsequent trial. It’s generally believed that Tassi was the model for Holofernes, she cast herself as Judith, and a female companion who failed to come to her aid during the rape (and failed to give evidence in her support at the trial) was the maid. It would therefore be natural to interpret this painting as part of her very understandable response to her own traumatic events.

Her second version, painted in 1620-21 and now in the Uffizi in Florence, is similar in most respects, although the view isn’t as tightly cropped on the three figures, so that it shows Holofernes’ legs and a deep red wrap around his lower body. The lower section of the blade is also executed better. Judith’s face shows intense concentration and effort, both arms thrust out straight in front of her. The left grips Holofernes by the hair, the right pushes the blade onwards. Her maid is seen holding Holofernes down, pushing hard with both her arms out straight too. Holofernes’s right hand seems to be pushing the maid back, but his left arm is folded over his body.

There’s more uncertainty as to whether her brilliant painting of the Allegory of Painting (c 1638-9) is a self-portrait. This striking angle of view can be accounted for if this was a self-portrait composed using two mirrors, one placed above and on the left of the painter, the other directly in front of her, where she is gazing so intently. If so, it was particularly ingenious because the reflection in the second mirror would have normal chirality (left and right would not be reversed).

However, it has been suggested that this isn’t a self-portrait, in which case her choice of view would have been most unusual. It’s believed to have been painted during her stay in London, possibly for King Charles I, as it appears to have passed straight into the Royal Collection, where it has remained ever since.

Returning to Italy, my last great woman painter is Elisabetta Sirani, oldest child of the Bolognese painter Giovanni Andrea Sirani (1610–1670), who had been a pupil of Guido Reni (1575–1642). She was running the family workshop by the time she was only seventeen. Her success was meteoric until she collapsed and died suddenly in August 1665, aged twenty-seven, and has since lapsed into obscurity.

Her Penitent Magdalene is a powerful painting using a wide tonal scale to heighten its emotive effect.

Her Portia Wounding her Thigh (1664) refers not to the Portia of Shakespeare’s play The Merchant of Venice, but to Portia or Porcia Catonis, wife of Marcus Junius Brutus, one of Julius Caesar’s assassins in 44 BCE.

Getting wind of the plot to murder Caesar, Portia asked Brutus what was wrong. He didn’t answer, fearing that she might reveal any secret under torture. She therefore inflicted wounds to her thigh using a barber’s knife to see if she could endure the pain. As she overcame the pain of her wounds, she declared to Brutus that she had found that her body could keep silence, and implored him to tell her. When he saw her wounds, Brutus confided all in her.

By August 1665 Sirani had completed nearly 200 paintings, many fine drawings, and various prints. She died so suddenly that it was at first suspected that she might have been murdered, but it transpired that she had suffered fulminating peritonitis as the result of a burst peptic ulcer.

In tomorrow’s article I will look at the life and work of their forerunner, Sofonisba Anguissola.

Here are this weekend’s Mac riddles to entertain you through family time, shopping and recreation.

1: First fruit at the top left since 1984.

2: Line of people uppermost for new documents and saving.

3: Formal inspection to customise window from above.

To help you cross-check your solutions, or confuse you further, there’s a common factor between them.

I’ll post my solutions first thing on Monday morning.

Please don’t post your solutions as comments here: it spoils it for others.

Here’s a bonus riddle for this weekend: what’s so invisible you can never see it in the Finder, is in many of the folders in your Home folder, and can break your backups? The answer is a .DS_Store file, officially a Desktop Services Store. Although they might appear more ancient, they originated in Mac OS X when its Finder was being rewritten from scratch in 1999.

It had been intended that Desktop Services would eventually gain a public API, but somewhere along the line Apple decided to keep it private, and their format and function have never been officially documented. Its name starts with a dot/stop/period to make it invisible in the Finder, and since macOS Sierra it has been made invisible even when the Finder reveals other invisible files. Currently the best way to see it is in Terminal, where the -a option to ls should include .DS_Store files.

They can be confused with another annoying but more useful hidden file: shadow files whose names start with ._ that are used to carry extended attribute data as part of the AppleDouble file format used on some FAT file systems. They too are invisible in the Finder even when hidden files are supposed to be displayed, but are associated with individual files rather than folders.

Function

The Finder will normally create a .DS_Store file in a folder that you have write access to, when some change is made to it in the Finder, such as creating or copying a file into that folder.

.DS_Store files contain a folder’s custom attributes, data like icon positions, and in more recent versions of macOS custom settings for the display of file metadata.

Among the most important of their contents for some users are Finder or Spotlight Comments, which are normally displayed in the Comments section of the Get Info dialog for a file. Those comments may also be duplicated in the com.apple.metadata:kMDItemFinderComment extended attribute (xattr) of that file, but that’s a secondary copy that can fall out of sync with what’s stored in the .DS_Store file, and the Finder ignores the xattr anyway. The reliance of Finder Comments on invisible .DS_Store files can lead to their unreliability compared with other forms of metadata.

Problems

You’re more likely to come across .DS_Store files when they make a nuisance of themselves by tripping something up. Send a folder from your Mac to a Windows or Linux system, for example, and it’s likely to confuse the recipient with that mysterious extra file that you can’t see at all. Send a folder to another Mac by AirDrop, and any .DS_Store file inside it will also accompany its visible contents. That in turn can cause problems with some backup utilities if it results in an older .DS_Store file being found in a folder that has already been backed up with a newer one.

Recent versions of macOS should no longer write .DS_Store files to computers connected to them over a network. If you want to stop them from being exposed in network volumes of older systems, use the command
defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool true
to disable that. One place .DS_Store files can prove particularly troublesome is in Git repositories. Mikey @0xmachos has provided a simple solution for eradicating them.

At one stage Apple even recommended that they should be explicitly excluded from servers used for network backups or other storage. They can trip up revision control systems, baffle those who open archives created on a Mac, stop folder copying, and confound folder comparison. The simple solution to these, as with so many other problems with .DS_Stores, is to open the folder containing that hidden file, move some of its contents about to force it to be refreshed, and move on.

In the past, .DS_Store files have been suspected of leaking data, and were involved in at least one security vulnerability. Thankfully they now seem as puzzling and opaque to the developers of malware as they are to other users, but I’m sure that one day, someone else will try to do bad things with them again.

Removal

You can recursively delete .DS_Store files from a hierarchy using the command
find . -name .DS_Store -delete
and Ross Tulloch’s BlueHarvest can automatically remove them.

In the first of these two articles I showed paintings of fish in myth and other narrative, and had reached examples of fish for sale when it had been landed on the beach.

When Anders Zorn was making the transition from watercolour to oil painting, he travelled to the fishing village of Newlyn, near Penzance in Cornwall, where there was an artist’s colony. When there in 1888 he visited the fishing port of Saint Ives, where he painted this Fish Market in Saint Ives.

Although Joaquín Sorolla had been brought up in Valencia and painted its fishing industry and beaches extensively, remarkably few of his paintings show fish.

In 1919, when he was painting his series of views of Spain for the Hispanic Society of America, those included the tuna market in Ayamonte, Tuna Fishing.

Fish have also appeared in more unusual settings.

Kazimierz Sichulski’s Fish (1908) is a startlingly original pastel painting, a virtuoso combination of reflections from and views through this water surface, to the fish beneath.

George Dunlop Leslie’s undated Goldfish Seller shows a hawker trying to sell goldfish to an upper middle class Victorian family. He may have arrived in the horse-drawn cart glimpsed outside the gate, and wears a bowler hat typical of itinerant traders, with a long green smock. The daughter and young son appear particularly unimpressed.

Lovis Corinth’s Woman with a Fishtank from 1911 shows the artist’s wife Charlotte in their flat on Klopstockstraße in Berlin. The aquarium, full of goldfish, is surrounded by quite a jungle of indoor plants, her little corner of vegetation within their city flat.

Painted in a combination of transparent watercolour and gouache, Walter Crane’s undated Diver is an unusual and challenging motif.

Finally, fish have been popular objects included in still life paintings, in what has become termed fruits de mer, the fruit of the sea.

Clara Peeters’ Still Life of Fish and a Candlestick is one of the earliest and most accomplished such paintings. She painted this in 1611, when she was in Amsterdam.

Among the first of Jean-Baptiste-Siméon Chardin’s successful still lifes is The Ray from 1727, exhibited the following year to secure his place in the Académie Royale de Peinture et de Sculpture. This is an extraordinary combination of objects, dominated by the ghostly ‘face’ of the hanging fish, ably supported by the anger of the cat.

After Chardin’s death in 1779, his successor Anne Vallayer-Coster reached her zenith, in brilliant displays such as A Still Life of Mackerel, Glassware, a Loaf of Bread and Lemons on a Table with a White Cloth from 1787. Although reminiscent of Clara Peeters’ fish, these lack the open-mouthed gawp.

The one artist who probably painted more fish than any other was William Merritt Chase, who characteristically dashed off a fish still life to warm up his brushes each day when he was teaching.

After completing his studies in Munich, Chase spent several months in Venice, where he painted one of his best-known still lifes, The Yield of the Waters, also known as A Fishmarket in Venice, (1878). This was probably his most complex and detailed still life, showing a wide variety of the fish and seafood available in the Mediterranean. It also established his own specialist sub-genre of still life: fish, characteristically set against a dark background.

Sometimes known as Diogenes or Havisham Syndrome, pathological hoarding is not uncommon. Where you wouldn’t expect to see it is in the Clock app bundled in macOS, where it can block its features from working. This article describes this bug that can affect macOS Sequoia and Tahoe. I’m very grateful for the persistent work of Michele, who has contributed much of this information.

Timer failure

Michele uses the Timers feature in the bundled Clock app frequently. Recently it has become temperamental, and now won’t display the contents of that view. He has spent a lot of time working with Apple Support, and trying various fixes, but the only way he has found to restore normal function is to use timers from a different user account.

He sent me two long log extracts collected from the moment he launched the Clock app, one with over 6,000 entries, and the other with more than 25,000. Despite Claude’s imaginary problems, I had been unable to discover anything wrong in either of them. Comparing them against a normal log extract there were no obvious differences or abnormalities.

Then someone suggested that he looked at com.apple.mobiletimerd.plist in ~/Library/Preferences, and removed the whole file. That immediately restored normal timer function, and now his Clock app is working perfectly again.

Service crash

Fortunately, one of the two log extracts he sent me contains the explanation. It transpires the Timers feature in the Clock app relies on mobiletimerd, and just over three seconds into that log record, the Clock app tried to fire up mobiletimerd to help it do its job.

mobiletimerd is a background process that relies on Mach IPC, so was launched by launchd to handle the user’s timers:
03.008036 gui/501/com.apple.mobiletimerd [19118] Successfully spawned mobiletimerd[19118] because ipc (mach)
03.062723 com.apple.mobiletimer.logging mobiletimerd starting...

About 0.03 seconds later, mobiletimerd had exceeded its 15 MB memory allowance. It was therefore terminated, leaving that service inactive, and the Timers view empty:
03.099138 kernel process mobiletimerd [19118] crossed memory high watermark (15 MB); EXC_RESOURCE
03.099148 kernel memorystatus: mobiletimerd [19118] exceeded mem limit: InactiveHard 15 MB (fatal)
03.100180 kernel mobiletimerd[19118] Corpse allowed 1 of 5
03.100567 kernel 54578.846 memorystatus: killing_specific_process pid 19118 [mobiletimerd] (per-process-limit 0 0s rf:- type:daemon) 15360KB - memorystatus_available_pages: 1327431
03.100665 com.apple.opendirectoryd PID: 19118, Client: 'mobiletimerd', exited with 0 session(s), 0 node(s) and 0 active request(s)
03.100679 gui/501/com.apple.mobiletimerd [19118] exited with exit reason (namespace: 1 code: 0x7) - JETSAM_REASON_MEMORY_PERPROCESSLIMIT, ran for 110ms
03.100708 gui/501 [100015] service inactive: com.apple.mobiletimerd

A later attempt to get mobiletimerd running again was delayed for 10 seconds, so occurred after the end of that log extract.

Hoarding

Michele had already discovered the cause of this excessive memory use, as its com.apple.mobiletimerd.plist file was nearly 7 MB. By the time that had been expanded into XML text, that could easily have accounted for 15 MB of memory. At first it looked as if this might have been damage or corruption of that property list, but it turns out that the file is fine, just far too big. So how could its preference settings become so large?

Each time you create and run a timer in the Clock app, mobiletimerd seems to append its details to the com.apple.mobiletimerd.plist file. In addition to arrays of MTAlarms and MTStopwatches, it collects MTTimers for every timer you create and run, but never seems to remove any. Thus the MTTimers list continues growing until mobiletimerd exceeds its memory limit and can no longer be run.

It’s not clear why this property list should store all these MTTimers. They’re not accessible to the user, who is only able to run the tiny subset still displayed in the window. Although none of the information in the property list is particularly sensitive, it does provide a full record of the times that each timer has been run, at least until the file occupies too much memory for the timer to function. It’s possible that mobiletimerd also hoards old MTAlarms and MTStopwatches that could result in similar problems.

Solution

The only workaround for those who use timers often is to periodically remove ~/Library/Preferences/com.apple.mobiletimerd.plist and so restore normal timer function. Although some of the solutions recommended to Michele would unintentionally have achieved that, they would also have involved a lot of wasted effort, and none can bring a permanent solution, so would have to be repeated every time that property list had grown too large.

Thus the only way to address this problem is for Apple to fix the bug. Michele has been told that Apple did fix a bug with that property list in Sequoia, although by the observations above it might have introduced a different bug.

Conclusion

If any part of the Clock app becomes dysfunctional, delete ~/Library/Preferences/com.apple.mobiletimerd.plist to see if that fixes it.

Because most fish aim to spend their entire lives underwater, where few artists go to paint, fish are seldom seen in paintings. That contrasts with those who try to capture fish by going fishing, an activity I have previously covered in this series in this article and a second.

Most of the aquatic creatures seen in paintings of myths, including those accompanying the god Neptune, appear to be caricatures of marine mammals including dolphins, or sea-monsters bearing no resemblance to fish.

One exception to this is Joseph Stella’s The Birth of Venus from 1922. As might be expected, his treatment is completely novel and seems to have benefited from visits to an aquarium. Aphrodite is shown at sea, in the upper part of the painting her upper body above the waterline, and below morphing into an aquatic plant underneath, where it finally merges into a helical shell. Matching the birds and flowers above the water are brightly coloured fish below.

Another interesting exception is Joachim Beuckelaer’s depiction of water in his Four Elements cycle from 1569. This shows A Fish Market with the Miraculous Draught of Fishes in the Background, the one place even landlubbers would come across fish, combined with the Gospel story in the far distance.

In the summer of 1872, as a one-off, Gustave Courbet painted an allegorical still life of The Trout, that is “hooked and bleeding from the gills”, a powerful expression of his personal feelings after being imprisoned for damage to the Vendôme Column during the Paris Commune the previous year.

JMW Turner recruits a school of fish for effect in his Slave Ship from 1840. His threatening sky and violent sea put the ship in the middle distance, silhouetted against the blood-red sky. The foreground is filled with the ghastly evidence of the slaves who were cast overboard.

Seen in amongst a feeding frenzy of fish and scavenging seabirds are hands raised from the waves in their final plea for rescue, a gruesome manacled leg, and various shackles used to restrain the slaves when in transit. Further back on the left a vague white form could represent spirits, and on the right is the thrashing tail of a sea monster.

Fish make the occasional appearance alongside legendary mermaids, as in Hans Thoma’s Three Mermaids from 1879. These mermaids are remarkably human in form, lacking fishtails, and frolic with fish under the light of the moon.

Historically the most important fish in Europe has been the humble herring. In the Middle Ages herring fisheries prospered and were the foundation of Copenhagen and Great Yarmouth, and influential in early Amsterdam. They remain strongly associated with the Netherlands and Nordic countries, where they are commonly preserved in brine (soused) or pickled.

Gabriel Metsu’s Woman Selling Herring (c 1661-62) is going from door to door with her fish, here trying to convince an old woman standing with a stick at the door of her dilapidated cottage in the Dutch Republic.

In Hans Andersen Brendekilde’s Home for Dinner from 1917, a young girl holding some fresh fish stands talking to a man with a spade.

JMW Turner toured the West Country as far as Cornwall in 1811, and the Tate Gallery has his ninety-page sketchbook recording many views of the Cornish coast from that visit. He later developed several into fine oil paintings, although it’s unclear whether this watercolour of St. Mawes, Cornwall, from about 1823, had its origins in those sketches and studies.

As with his paintings of other coastal areas, Turner shows a fishing boat coming in to a beach to land its catch, and the great activity in the open air fish market in the foreground. Behind are typical Cornish cottages stepped up from the shore to the top of the coastal cliffs, and the castles of St Mawes (closer) and Pendennis, in Falmouth (more distant, on the other side of this estuary).

Richard Dadd’s Fish Market by the Sea, from about 1860, shows an impromptu open-air fish market, run by the fishermen’s wives, to sell their husband’s catch as soon as it had been landed.

Trim is one of the Dark Arts of SSDs. It’s important if not essential, but it’s not easy to discover whether an SSD is Trimming properly. Some say that you need to enable Trim for external SSDs, yet others don’t and never seem to encounter a problem.

Why Trim?

Data stored on a hard disk doesn’t need to be erased before the space it takes can be reused, but SSDs work differently. Before a page of SSD memory can be reused, it must be erased, and that’s the part that takes time. If a fast SSD had to erase each page when it needed to write to it, that SSD wouldn’t be much faster than a good hard disk.

To overcome this problem, when the file system has pages that no longer contain data in use, it should tell the SSD that they’re free so they can be erased to prepare them for reuse. In SATA SSDs that’s performed by the TRIM command, and its equivalent for faster NVMe SSDs is DEALLOCATE, although it’s the older command whose name has stuck.

Modern SSDs also perform their own housekeeping, and in many cases may not need to be Trimmed at all. However, when an operating system and SSD both support Trim (or DEALLOCATE), that should ensure optimum performance.

When an SSD doesn’t get Trimmed and can’t compensate for that with its own housekeeping routines, its performance suffers noticeably. This is most commonly seen with SATA SSDs that would normally have write speeds of around 500 MB/s. When they need a good Trim, that can fall to around 100 MB/s, the same speed you’d expect from a hard disk. But this doesn’t affect read speeds at all, so one way of telling whether an SSD needs Trimming is to measure its read and write speeds.

Which SSDs are Trimmed?

You’ll be delighted to know that, for their relatively high cost, all Apple internal SSDs Trim reliably, without any need for tweaking any settings.

As a rule, external SSDs don’t Trim by default if they have a SATA interface, giving them read and write speeds of about 500 MB/s. Those with faster NVMe interfaces, including those connected by Thunderbolt 3-5 or USB4, should Trim by default when they’re formatted in APFS.

System Information normally lists a drive’s Trim support, if you can find the right section. Browse its Hardware section to discover the protocols the drive supports. These can be confusing, as the SSD and its enclosure may well have multiple entries in different headings, and some of the information may appear conflicting.

USB4 drives operating in Thunderbolt 3 mode can also be confusing. When connected to an Intel Mac (which doesn’t support USB4 itself) they may be reported in the Thunderbolt/USB4 device tree as being USB4.0 operating in Thunderbolt 3 mode, with a link speed of up to 40 Gbit/s, then in the NVMExpress device tree with a link width of x4 and speed of 8.0 GT/s.

SATA drives should appear in the Serial-ATA device tree, even though they might be connected via Thunderbolt 3, and you may see a statement of Trim support.

Device trees worth inspecting include: NVMExpress, PCI, SATA, Storage, Thunderbolt/USB4 and USB.

Which file systems Trim?

Trim is well-demonstrated in SSDs formatted in APFS, and is known to occur in HFS+. However, old PC files systems like ExFAT don’t have any Trim support, and it can’t be enabled in a Mac at least.

Unfortunately, as HFS+ is now an old Mac filesystem, it can’t readily be seen in log entries, while those from APFS contain valuable detail that makes them suitable for use when testing for Trim.

How to verify Trim

Use Mints to verify whether your external drive does get trimmed correctly when it’s mounted, using its Disk Mount feature. In essence, what you do is:

1. Eject and disconnect the external drive.
2. Connect the drive at a known time, according to the Mac’s clock.
3. Leave the Mac alone until all that disk’s volumes have been mounted.
4. 20 seconds after connecting the drive, or 10 seconds after the last of its volumes has mounted, open the Mints app.
5. Click on the Disk Mount button, and set the time in its log window to the time at which you connected the drive.
6. Set the period to a minimum of 20 seconds, long enough to cover the period up to 10 seconds after the last volume mounted.
7. Uncheck all the category checkboxes except the first, APFS +.
8. Click the Get log button.
9. When log entries are displayed, scroll to the end and look back for APFS trim entries.

This only works for APFS, though, as log entries for HFS+ don’t appear to show Trimming in this way.

Those entries are characteristically of the form
23-03-25 19:01:06.930 apfs spaceman_scan_free_blocks:3311: disk5 scan took 0.030901 s (no trims)
23-03-25 19:01:10.960 apfs spaceman_scan_free_blocks:3293: disk5 scan took 4.030544 s, trims took 3.944665 s
23-03-25 19:01:10.960 apfs spaceman_scan_free_blocks:3295: disk5 471965989 blocks free in 9131 extents
23-03-25 19:01:10.960 apfs spaceman_scan_free_blocks:3303: disk5 471965989 blocks trimmed in 9131 extents (432 us/trim, 2314 trims/s)
23-03-25 19:01:10.960 apfs spaceman_scan_free_blocks:3306: disk5 trim distribution 1:1461 2+:1267 4+:4121 16+:785 64+:822 256+:675

Check that the named disk, here disk5, is the SSD or APFS container on the SSD that you’re checking. If it has entries reporting that blocks have been trimmed, this confirms that the SSD has been trimmed as expected. Disks that don’t trim normally only show the first of that series, ending in the words no trims.

It’s possible to enable Trim for all external storage using the trimforce command, but you should normally verify that your external SSD does Trim correctly when mounted.

If you have an SSD that hasn’t been Trimming and is suffering poor write performance, you may be able to help it recover by copying its contents to another disk, then erasing its volumes, or the whole container. Those should return their whole contents as free space, and so enable the SSD’s own housekeeping to erase them in readiness for reuse.

Painting in the Golden Age didn’t occur in isolation, but was greatly influenced by artists of Flanders and Brabant to the south, many of whom visited or migrated to the Dutch Republic. Some Dutch artists effectively exported their landscape and other skills to Italy, where there was a group of emigrés known as the Bentvueghels (meaning birds of a feather) between about 1620-1710.

From the late 1590s until well into the following century, the distinctive style of Caravaggio (1571-1610) drew followers across Europe, most of whom saw his paintings when they were training in Italy. This wave of Caravaggism spread when those painters returned to their native lands, including the states of the Dutch Republic.

Caravaggio’s style was by no means unique, and his use of chiaroscuro had been anticipated a century earlier in this wonderful nocturne by the early Netherlandish painter Geertgen tot Sint Jans, Nativity at Night, thought to be from about 1490. Chiaroscuro makes narrative sense here, and results in a scene of great tenderness and reverence, thanks to its soft transitions of tones.

Caravaggio’s third painting of Salome Receives the Head of John the Baptist was completed in about 1609-10, shortly before his death, and illustrates his style at its height.

Artemisia Gentileschi’s father was a well-known Caravaggist, and she followed suit for the early years of her career. Her painting of Judith Slaying Holofernes followed a decade later in 1620-21. Over that period, Hendrick ter Brugghen, Gerrit van Honthorst, Dirck van Baburen and Jan van Bijlert became influenced when in Italy, and returned to Utrecht, where they have become known as the Utrecht Caravaggists.

Van Honthorst’s The Soldier and the Girl from about 1621 is a good example, where the young woman is lighting her candle from a burning coal.

Van Honthorst’s dimly lit indoor scenes are associated with pleasures, often fairly sinful ones, as in his Merry Company from 1623. He shows here how directional lighting can transform appearance, turning quite ordinary or ugly faces into caricatures.

As music was breaking out of seedy dens of iniquity into mainstream culture, learning to play an instrument and playing to others became fashionable, as shown in van Honthorst’s merry Concert on a Balcony from 1624.

During the 1620s his paintings became more narrative and less Caravaggist, as seen in his Solon and Croesus from 1624. This shows the elderly Greek statesman getting a hostile reception from Croesus, with his court laughing at his responses. Included are two slaves supplicating themselves before the king, in an interesting condemnation of slavery for its time.

Some more mainstream artists also showed Caravaggist tendencies.

Rembrandt’s very early painting of The Operation from 1624-25 shows a barber-surgeon and his assistant performing surgery on the side of a man’s head, by the light of a commonplace candle on a candlestick holder.

Hendrick ter Brugghen’s religious narrative of Jacob Reproaching Laban for Giving him Leah in Place of Rachel is from the later years of Caravaggism, in 1627.

Although remarkably little is known of the paintings of Judith Leyster, she appears to have been influenced when painting in Haarlem.

Like most of her surviving paintings, A Game of Tric-Trac was made before her marriage to Jan Miense Molenaer, in this case in 1630.

Although Rembrandt’s use of chiaroscuro is best known from his later paintings, Saint Peter in Prison (The Apostle Peter Kneeling) dates from 1631.

Later interiors and genre works show the more lasting influence imported from Italy.

Erasing SSDs securely has been a longstanding problem that has been solved in Macs with T2 or Apple silicon chips, with the introduction of Erase All Content and Settings (EACAS) four years ago in macOS Monterey. This article explains how it works, what it does, and when you should use it.

Boot disk

While Intel Macs are simpler, the internal SSD of an Apple silicon Mac is divided into three APFS containers/partitions.

Intel Macs have the same Apple APFS container with the Boot Volume Group in it, but the other two containers are replaced by a single small EFI partition.

macOS manages and uses the first two containers, ISC and Recovery, and that containing the Boot Volume Group is the one we’re concerned with. That includes the System and Data volumes, the former being made into a read-only snapshot that’s mounted as the Signed System Volume and contains macOS. Everything you install as a user, including apps and your Home folder, is in the Data volume, which is encrypted automatically even if you don’t have FileVault turned on.

Data volume

As the Data volume is invariably encrypted, the best way to securely erase its entire contents is to destroy its encryption key. Provided that can be performed robustly, so the key can never be recovered, no one will be able to decrypt its contents. (There is an expectation that one day it might be possible to break the encryption using quantum computing, but that’s not something you should be concerned with at present.)

The encryption key used to encrypt the Data volume is itself encrypted, and forms part of the mechanism used by FileVault when that’s enabled. To ensure that those encryption keys don’t leave the Secure Enclave, they’re encrypted again, and the key that’s destroyed by EACAS is one of those. macOS also employs anti-replay techniques to ensure that previous keys can’t be reused.

Additional features

In addition to destroying the encryption key for the Data volume, EACAS performs other useful tasks. These include signing out of your Apple Account, including iCloud and iCloud Drive, destroying all fingerprints used for Touch ID, and turning off Location Sharing to disable Find My and Activation Lock.

Although I can’t find any official account of additional data being erased by EACAS, I believe that all LocalPolicy records stored in Apple silicon Macs are also destroyed. LocalPolicy authorises access to external bootable disks, so those who have configured an external disk to boot their Mac are likely to be required to re-authorise it before it will boot that Mac again.

What EACAS doesn’t do, though, is sign you out of third-party cloud or other services such as Adobe’s Creative Cloud, or deauthorise that Mac for Apple media such as Music. Neither will it do anything to your Mac’s SSV: that’s left intact, still running the same version of macOS.

How to use EACAS

Start EACAS from System Settings > General > Transfer or Reset > Erase All Content and Settings…. In older versions of macOS still using System Preferences, open them and it’s offered as a command in the app menu.

If you continue, you should see one final warning before the contents of the Data volume are blown away into the great bit-bucket in the sky.

What’s left of your Data volume, shown here in Recovery mode, is a mere 300 MB or so.

When to use EACAS

If you want to wipe your Mac’s Data volume so you can reinstall its user(s), EACAS is the simplest and quickest way to do that, and doesn’t require starting up in Recovery. Its additional features ensure that, when you install its new primary user, everything should work properly and you don’t end up with ghost Macs left over from the past.

It’s the method of choice when preparing your Mac for disposal, particularly if you’re passing it on to someone else, as it ensures that no one can recover any of the data stored in your Home folder, or anywhere else on its Data volume. Performing that manually requires you to work through a list of additional procedures, almost all of which are automatic in EACAS.

The only time when you’re likely to prefer a different method is when you want to erase both the Data and System volumes, perhaps to return to an older version of macOS. Although you can do that using Disk Utility in Recovery mode, that doesn’t install the matching firmware. If you really want to return to factory-fresh conditions, the best way is to put that Mac into DFU mode, then restore it from the IPSW image file for that version of macOS. Although that does require a second Mac, it’s quick and comprehensive.

One other caution: never use EACAS on a macOS VM, as it’s unlikely to recover. It makes more sense just to delete the whole VM and be done with it.

Summary

• EACAS performs a secure erase of the Data volume, as well as some useful extras.
• It’s the method of choice for preparing your Mac for disposal.
• It’s also suitable for wiping user data before setting your Mac up afresh, using its existing macOS.
• If you want to wipe the System volume as well, to reinstall macOS, restore from an IPSW in DFU mode.

Long before paintings became movable objects of great value used by the rich as investments, artists and the owners of their paintings wanted to protect the paint layer that had been so carefully applied to the ground. From the early Middle Ages onwards, one popular means of doing this has been to apply some form of protective layer, a varnish.

Varnishes have been widely used not only for protection. Careful choice of their composition can enhance the appearance of a painting, through the optical properties of the varnish medium and its smooth, glossy surface. Until the late nineteenth century, the great majority of painters either applied final layers of varnish themselves, or advised their patrons and clients to do so.

Three types of varnish have come into common use:

• Drying oil and resin, in effect a resin-rich transparent and unpigmented paint layer, that usually becomes an integral part of that. Some artists have added pigment, perhaps to make a general colour adjustment. There isn’t any clear distinction between that and a final paint glaze.
• Solvent and resin, from which the solvent will evaporate, leaving a thin surface coat of resin.
• Water-based washes such as egg white, known as glair, vegetable gums like gum arabic, and animal glues.

Resins used in varnishes have rich and sometimes strange histories. Most are exudates from trees in exotic locations, and have evocative names like mastic, sandarac, colophony and dammar. They’re usually highly insoluble, either in drying medium that has to be heated to make oil-based varnishes, or in turpentine or similar organic solvents. A great many recipes have been proposed, and there’s always the lure of the perfect, and inevitably top secret, formula.

The biggest problems with varnishes are their propensity to yellow or grey with age, and their tendency to take up dirt and atmospheric contaminants. Rembrandt’s first painting of Bathsheba at her Toilet from 1643 has sadly lost much of its detail into the gloom of old varnish, which can be almost impossible to clean off when composed of drying oil and resin, without damaging the paint layer underneath.

Any work older than a few decades that has been varnished or had any form of surface treatment is unlikely to appear today with the colours the artist intended. Multiple layers of old varnish and trapped dirt give a misleading impression of what we would have seen soon after the work was completed. Painstaking work by conservation specialists can often restore old paintings to what we presume is their former glory, in full colour again.

Hieronymus Bosch’s Christ Carrying the Cross (1490-1510) is seen above before recent conservation work, and below is the result of thousands of hours of painstaking cleaning and treatment.

Another problem for the conservation specialist is a painting like Edward Poynter’s A Visit to Aesculapius from 1880. Although this is little more than a century old, the evidence from contemporary prints made from this work is that it was originally far from being so dark. Sadly it’s now almost impossible to read as a result of its near-black shadows.

A good varnish should be both colourless and transparent, but painters haven’t always respected that.

When finishing his monumental Raft of the Medusa in 1819, Théodore Géricault is thought to have applied glazes or varnish containing asphalt to give the painting a deep brown tone. Asphalt is not only completely unprotective and almost attracts dirt, but it never fully dries, and can have adverse effects on underlying paint too. It hasn’t helped that this two hundred year-old painting was rolled up and stored in a friend’s studio when it remained unsold, and was then transported to London still rolled up the following year.

Conventional wisdom says that it’s best to leave an oil painting to dry for at least six months before varnishing it. JMW Turner sometimes varnished over paint layers that were far from dry. In the case of The Opening of the Wallhalla, 1842 (1843), painted on mahogany, Ruskin reported that it had “cracked before it had been eight days in the Academy Rooms”, although this overall view shows little evidence of that damage.

Hellen and Townsend attribute this to Turner’s extensive use of Megilp, here a product sold by his colourman containing leaded drying oil and mastic varnish. Used sparingly and with great caution, such medium modifiers don’t necessarily cause serious ill-effects. But Turner has used Megilp to excess, to produce a soft impasto used in the foreground figures, in particular. This has resulted in wide and shallow drying cracks, as the surface has dried quickly and shrunk over trapped layers of liquid paint.

Varnishes do provide mechanical protection to the paint layer, but at the cost of locking out atmospheric oxygen, required for drying oils to polymerise properly in their drying process. Applied too early, varnishes can therefore greatly slow drying of underlying paint layers; the danger is that they may saponify (turn to soap) instead of drying normally.

Despite these dangers, varnishes can, when used with care by those who understand them properly, be valuable beyond simply providing a protective coat. Kirsty Whiten’s The Quing of the Now People (2015) achieves its superbly realistic effect by the skilful combination of conventional oil paint with varnish.

In the late nineteenth century, attitudes to varnishing oil paintings changed markedly, as Impressionists like Camille Pissarro started to prescribe that their works should on no account be varnished. This was to preserve the soft matte surface of the paint as applied by the artist, and became increasingly popular in the twentieth century.

For such paintings, protection can be provided by glass, when necessary. That isn’t of course an option for many extremely large oil paintings on canvas, which will probably need to be varnished and cleaned periodically well in the future, as they have in the past.

Varnishes, usually of the third type containing vegetable gums or animal glues, have also been used extensively on paint layers other than oils.

These are reported in Samuel Palmer’s Tintern Abbey at Sunset, above, and Dante Gabriel Rossetti’s Lucrezia Borgia, below. Gum or glue varnishes can have impressive optical effects when used carefully on watercolours.

Unfortunately, their tendency to yellow can also cause colour shifts. William Blake liked to apply glue varnish to his watercolours and perhaps to his glue tempera paintings as well. In the case of his Penance of Jane Shore in St Paul’s Church from about 1793, this has resulted in a generalised yellow shift and loss of chroma.

Other artists appear to have been more successful: Henry Ossawa Tanner apparently applied varnish to this tempera painting of The Destruction of Sodom and Gomorrah almost a century ago, and it doesn’t appear to have suffered any adverse consequences, yet.

Varnishing has become such an accepted process that major exhibitions have incorporated ‘varnishing days’, although what happens on those occasions can be quite different. In Turner’s day at the Royal Academy in London, Varnishing Day was an occasion for artists to make any last-minute changes, and Turner himself seems to have turned up armed with paint and brushes and continued to work on his paintings.

Varnishing Day in the Paris Salon was completely different, attended normally by the artists’ colourmen, who applied a coat of varnish to the paintings for which they were responsible. The artists themselves don’t seem to have been involved, unless they chose to apply the varnish in person.

When you’ve tried all the logical solutions, restarted, had a go in Safe mode, and still can’t solve a problem, you may need to bring the big guns to bear on it. These are radical fixes that carry a risk of going further than you want, but are all you’ve got left. You might have been recommended them by someone who seems to know best, or, as we saw last week, by an AI. This article looks at the state of those big guns in Tahoe 26.1, and which you should consider seriously.

Reset NVRAM and SMC

Although quick and simple to use, resetting the NVRAM and SMC are well known for fixing all sorts of problems. They’re still valuable in Intel Macs, but you can forget them in Apple silicon, as the SMC resets with each startup, and the NVRAM is protected from user access. The only way you could reset an Apple silicon Mac’s NVRAM is by Restoring it in DFU mode, which almost certainly isn’t something you want to do at this stage.

Reset TCC

TCC is the subsystem responsible for implementing privacy protection, and is notorious for its mystifying misbehaviour. Before convincing yourself that doing anything with TCC is going to help a problem, you should really look for a pattern of misbehaviour that points to one of the resources that it controls access to. If possible, tie this to a single app and use
sudo tccutil reset All com.apple.clock
for example to reset just that one app’s privacy settings.

TCC is also a popular recommendation in solutions that lack a firm logical basis, where there’s no attempt to target one app, but go for the lot with
sudo tccutil reset All
The effect of that is to empty every section (apart from Location Services) in Privacy & Security settings. That’s certain to stop many apps from working properly, and you’ll end up adding them back one by one over the following days or weeks. In some cases, even that doesn’t prove sufficient, and deleting TCC’s database seems the only way forward. That and other issues are discussed here.

tccutil doesn’t appear to have changed in any significant way in Tahoe.

Delete LaunchServices’ database

LaunchServices handles many features including opening apps, populating their Open Recent menu commands, and handling much of the integration of apps with their documents. To achieve that, it maintains an extensive database of apps and other executable components.

Access to LaunchServices’ database and control over it is provided in the lsregister command, buried deep in /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support, although there’s a public lsappinfo tool that provides different features and is seldom used. Earlier this year I gave an account of its use in Sequoia, but its most popular option to kill the LaunchServices database has been removed from Tahoe “because it was dangerous and no longer useful”, a fair assessment.

Repair permissions

I have recently reexamined the various forms of repairing permissions. If anyone or anything recommends you run
sudo /usr/libexec/repair_packages --verify --standard-pkgs
you shouldn’t listen to another word they say, as that form went out with El Capitan, and isn’t even possible with a modern version of macOS.

The more modern replacement, initiated by the command repairHomePermissions in Recovery mode, may once have had a purpose, but is now grossly disruptive, as it locks the user out of most of the contents of their Home folder by removing them as their owner.

It would take you hours to restore your Mac to a usable state after performing that ‘repair’. If anyone recommends that you try it, ask them when they last used it successfully.

Clean install

Tahoe does provide convenient methods for clean installing macOS, as described here. One of the simplest is to Erase All Content and Settings using the EACAS option in Transfer or Reset, in General settings. That renders all your data inaccessible by securely erasing its encryption key, then you can migrate from your latest backup when setting up your currently installed version of macOS afresh.

If you want to go back to fresh firmware and macOS as well, then the simplest way is to Restore in DFU mode, as explained here. That also gives you the choice of using any compatible IPSW, making it possible to perform a full downgrade to an earlier version of macOS if you wish. Remember that Apple silicon Macs can’t run a version of macOS that was released before that model shipped. If in doubt, consult Mactracker’s database for the original version shipped with that model.

Summary for Apple silicon Macs:

• Resetting SMC and NVRAM is not possible (still available for Intel).
• Resetting TCC is still available.
• Killing the LaunchServices database is no longer available (but still in Sequoia).
• Repairing permissions is grossly disruptive and should be avoided.
• Clean install can be confined to the Data volume, or include firmware and macOS.

Whatever you choose, I wish you success.

Apple has just released its regular weekly update to XProtect, bringing it to version 5323. As usual, it doesn’t release information about what security issues this update might add or change.

This version adds five new Yara rules in its TIMELYTURTLE series, for MACOS.TIMELYTURTLE.DYCASWOC, MACOS.TIMELYTURTLE.DYCASWOCB, MACOS.TIMELYTURTLE.LELINO, MACOS.TIMELYTURTLE.TRNO, MACOS.TIMELYTURTLE.DYHEOC, and a single new rule for MACOS.REALSTAR.VO, which appears to be a new genus of malware.

You can check whether this update has been installed by opening System Information via About This Mac, and selecting the Installations item under Software.

A full listing of security data file versions is given by SilentKnight and SystHist for El Capitan to Tahoe available from their product page. If your Mac hasn’t yet installed this update, you can force it using SilentKnight or at the command line.

If you want to install this as a named update in SilentKnight, its label is XProtectPlistConfigData_10_15-5323

Sequoia and Tahoe systems only

This update has at last been released for Sequoia and Tahoe via iCloud. If you want to check it manually, use the Terminal command
sudo xprotect check
then enter your admin password. If that returns version 5323 but your Mac still reports an older version is installed, you should be able to force the update using
sudo xprotect update

Update

As of 22:00 GMT on 11 November, the update to 5323 has reappeared for download to the traditional location via Software Update or SilentKnight, and is available through the iCloud connection for Sequoia and Tahoe.

Over the previous fifteen articles Dante has taken us through his vision of Hell. As he journeys on to Purgatory, this article offers an overview of the best-known book in his Divine Comedy.

It was Botticelli who provided the clearest pictorial map of Dante’s journey, as he descended with Virgil through a succession of circles, each with its own class of sinner. Highest are the woods where Dante was wandering when he encountered the three wild beasts. At the left, Virgil led Dante down to the area where the cowards are trapped, neither being allowed admittance to Heaven, nor to Hell. Charon’s boat then crosses the River Acheron, shown in blue, taking Dante and Virgil to the First Circle of Limbo.

Introduction

This journey starts just before dawn on Good Friday in 1300, when the poet is wandering lost in a dark wood. His way is blocked first by a leopard, then by a lion, and finally by a wolf.

1 To the gates of Hell

Forced to retreat back into the wood, Dante comes across a man who introduces himself by way of a riddle, leading Dante to recognise him as the ghost of the classical Roman poet Virgil. He tells Dante that the only way out is to pass through the eternity of Hell. When the pair reach the gate of Hell, they read its warnings, culminating in the bleak exhortation: leave behind all hope, you who enter.

They first encounter those stuck forever on the periphery, those whose lives were too cowardly to enter Heaven or Hell, who are stung repeatedly by flies and wasps.

2 Abandon hope

They then cross the River Acheron in Charon’s ferryboat, and enter the First Circle of Limbo, a place of tranquil and calm. Here are the souls of those who led honourable lives before the Christian era, and others who never had the opportunity to follow Christ. These include the great classical writers: Homer, Horace the satirist, Ovid and Lucan. Together with Virgil, these five invite Dante himself to join them as the sixth among the ranks of great writers, in an ambitious piece of self-promotion.

3 In Limbo

Virgil leads Dante down to the Second Circle, for those guilty of the sin of lust.

Here the lustful are thrown around by vicious winds, and Dante hears the tragic story of Paolo and Francesca da Rimini, that inspired many fine paintings.

4 Paolo and Francesca

Passing the three-headed dog-monster Cerberus, Virgil takes Dante on to the Third Circle, full of gluttons wallowing in stinking mud, under a constant deluge of rain, sleet and snow. In the Fourth Circle, they see a mixture of the avaricious and prodigals pushing great boulders in opposite directions.

5 Cerberus and gluttony

The Fifth Circle holds the swamp of the River Styx, in which sullen spirits are submerged and the wrathful fight one another. Dante and Virgil cross this in a boat piloted by Phlegyas, who deposits them at the gate to the city of Dis, entrance to the lower parts of Hell. The gate is slammed shut on them, and requires a messenger from Heaven to let them through.

6 Money and anger

Here Dante enters the Sixth Circle, for heretics who denied the soul’s immortality, among them the Florentine Farinata degli Uberti, who is imprisoned in a tomb. The pair are carried by Nessus the Centaur on to the Seventh Circle, for the violent.

7 Furies and heresy

These not only include tyrannical warriors like Attila the Hun, murderers and bandits, but those whose violence was directed at their own lives in suicide, who are trees in a wood and kept in perpetual pain by harpies feeding on them. The pair then cross a desert on which fire rains to torment the souls of blasphemers, sodomites, and usurers.

8 The Minotaur, killers and suicides

Dante learns of a statue of an old man on Mount Ida, on the island of Crete, whose tears form the rivers of Hell.

9 Violence against God

Virgil guides Dante onto the back of Geryon, formerly a king slain by Hercules and condemned to suffer in Hell for his fraud, who flies the pair on to the Eighth Circle, for the fraudulent. This is divided into a series of rottenpockets, depressions in which different types of fraudster are confined. They pass through the areas for pimps, flatterers, corrupt religious leaders, sorcerers, corrupt officials and hypocrites.

10 Fraud

Among the corrupt religious leaders or simonists is Pope Nicholas III, who had been shamelessly nepotistic.

The later rottenpockets contain thieves, those who gave fraudulent counsel, those who sowed discord, and falsifiers and imposters of various kinds. Thieves are attacked repeatedly by snakes to undergo their own reptilian transformation.

11 Bribery, hypocrisy, theft

Among these many cheats and frauds are those who fight one another, and sink their teeth into flesh.

12 Fraud and inciting division

Dante and Virgil are lowered into the Ninth Circle by Antaeus, one of the giants who stand guard around its periphery.

There is the lake of Cocytus, in which those guilty of treachery are frozen and suffering for eternity. These include souls of those who were treacherous against their relatives, their homeland, guests and benefactors.

13 Treachery

Among them is Count Ugolino, who sinks his teeth into the neck of Archbishop Ruggieri, who left him to starve to death in a cell.

14 Count Ugolino

Finally, Dante and Virgil see Lucifer himself, before leaving Hell.

15 Lucifer himself

The artists

William Blake (1757–1827) was a British visionary painter and illustrator whose last and incomplete work was an illustrated edition of the Divine Comedy for the painter John Linnell. Most of his works shown in this series were created for that, although he did draw and paint scenes during his earlier career. I have a major series on his work here.

Sandro Botticelli (1445–1510) was one of the leading painters of the early Southern Renaissance, working in his native city of Florence. In addition to his huge egg tempera masterpieces of i (c 1482) and The Birth of Venus (c 1485), he was a lifelong fan of Dante’s writings. He produced drawings which were engraved for the first printed edition of the Divine Comedy in 1481, but these weren’t successful, most copies only having two or three of the 19 which were engraved. He later began a manuscript illustrated edition on parchment, but few pages were ever fully illuminated.

William-Adolphe Bouguereau (1825–1905) was a precocious and highly-acclaimed academic painter who dominated the Salon in the late nineteenth century with his figurative works, often drawn from mythology. Classically-trained at the École des Beaux-Arts, he grew infamous for his nudes painted against false settings, and his vehement opposition to Impressionism. However, he taught at the Académie Julian, and worked tirelessly even when his paintings fell from favour.

Jean-Baptiste Camille Corot (1796–1875) was French, and one of the most prolific and greatest European landscape artists of the nineteenth century, who was key to the development of Impressionism. Following in the classical tradition, he also painted several narrative works set in those landscapes.

Eugène Delacroix (1798–1863) was a major French painter whose Romantic and painterly style laid the groundwork for the Impressionists. In addition to many fine easel works, he painted murals and was an accomplished lithographer too. Many of his paintings are narrative, and among the most famous is Liberty Leading the People from 1830. This article introduces a series featuring his major works.

Gustave Doré (1832–1883) was the leading French illustrator of the nineteenth century, whose paintings are still relatively unknown. Early in his career, he produced a complete set of seventy illustrations for translations of the Inferno, first published in 1857 and still being used. These were followed in 1867 by more illustrations for Purgatorio and Paradiso. This article looks at his paintings.

Joseph Anton Koch (1768-1839) was an Austrian landscape painter, who worked mainly in Neoclassical style. During his second stay in Rome, he was commissioned to paint frescos in the Villa Massimi on the walls of the Dante Room there, which remain one of the most florid visual accounts of Dante’s Inferno. He completed those between 1824-29. He also appears to have drawn a set of illustrations for Dante’s Inferno in about 1808.

Purgatory and Paradise

Although Heaven and Hell have clear biblical roots, the concept of Purgatory as part of the Christian life after death is more recent. It originated in the early Christian Church, flourished in the Middle Ages, and ripened only in the Catholic Church after the schism of Protestants in the Reformation during the sixteenth century. It can be seen as a route to Heaven for those who had sinned on earth, so long as they had confessed and repented.

Dante had much greater freedom in imagining what Purgatory might be, and adopted a physical structure that is the exact inverse of his vision of Hell: a mountain rising through seven terraces to culminate in a terrestrial paradise at the summit. Each terrace then accommodates a class of sin, rising from pride at the foot to lust just below Paradise.

The least-known of the three books in Dante’s Divine Comedy, Paradise was its most important to contemporary readers. Having given gruesome detail of what would await them in Inferno, and the penance they would have to pay in Purgatory, Paradise must be everyone’s ultimate aspiration. Dante invokes classical cosmology in nine concentric shells rather than the simple physical structures of the two previous realms, which for many readers is more nebulous.

References

Wikipedia
Danteworlds

Robin Kirkpatrick (trans) (2012) Dante, The Divine Comedy, Inferno, Purgatorio, Paradiso, Penguin Classics. ISBN 978 0 141 19749 4.
Richard Lansing (ed) (2000) The Dante Encyclopedia, Routledge. ISBN 978 0 415 87611 7.
Guy P Raffa (2009) The Complete Danteworlds, A Reader’s Guide to the Divine Comedy, Chicago UP. ISBN 978 0 2267 0270 4.
Prue Shaw (2014) Reading Dante, From Here to Eternity, Liveright. ISBN 978 1 63149 006 4.

I hope that you enjoyed Saturday’s Mac Riddles, episode 333. Here are my solutions to them.

1: Black leopard exposé of 2003 could fax.

Click for a solution

Mac OS X 10.3 Panther

Black leopard (a panther) exposé (Exposé was one of its new features) of 2003 (released 24 October 2003) could fax (it was the first Mac OS X to come with integrated support for faxing).

2: Officially a 750, it brought the fastest notebook in the world in 1997.

Click for a solution

G3

Officially a 750 (its proper name is the PowerPC 750), it brought the fastest notebook in the world (the PowerBook G3) in 1997 (first Macs with the G3 came in November 1997).

3: Came with a plus, bulging trash and SCSI.

Click for a solution

System 3

Came with a plus (it shipped with the Mac Plus in January 1986), bulging trash (it was the first version of Mac OS to show the Trash bulging when it had items inside it) and SCSI (it was the first version to support SCSI devices).

The common factor

Click for a solution

The number 3, to celebrate Mac Riddles 333.

I look forward to your putting alternative cases.

macOS gives you the choice of upgrading to the latest version, but each year makes it easier to upgrade by mistake. For those wanting to stick with macOS 15 Sequoia this has become even harder to get right. This article shows how you can install security updates without risking the upgrade, using my free utility SilentKnight. If you prefer you can do essentially the same thing from the command line.

Check for updates

Run the latest version of SilentKnight (2.12) and it will show you all the updates waiting for your Mac, including the Tahoe upgrade. Don’t, whatever you do, click on the Install all updates button at this stage, or try installing individual updates. Quit SilentKnight and open Software Update in System Settings to install the security update to Sequoia first.

Update macOS

Although you can download and install macOS updates using SilentKnight, it’s far better if you use Software Update to do that. Open that in System Settings and read what it offers very carefully.

Although you know you don’t want to click on Upgrade Now, you should also avoid clicking on Update Now in the expectation that it will update Sequoia to 15.7.2. Instead, click on the ⓘ button next to it to ensure that you only update what you intend.

In this window, uncheck the Tahoe upgrade, and tick macOS Sequoia 15.7.2 and Safari, then click on Update Now. Make a mental note of the large size of the Tahoe upgrade, and when the download starts, check that isn’t being downloaded. If it is, cancel it if you can, quit all other open apps, and shut your Mac down. Leave it a few seconds before starting it up and trying again.

Once the Sequoia security update has been installed and your Mac restarts into 15.7.2, open SilentKnight and let it check for updates again.

Install remaining security updates

In most cases, almost all the outstanding security updates such as XPR should now be installed as part of that macOS update. However, the one you’re likely to have to install manually is XProtect, and you also want to change SilentKnight so it doesn’t put you at risk of inadvertently upgrading to Tahoe.

Open SilentKnight’s Settings and uncheck Allow Install All Updates. That removes the button from its main window that you could click accidentally and initiate an upgrade.

Now open Terminal to install the outstanding XProtect update. Type the following command
sudo xprotect update
press Return and enter your admin password. That update should then be installed from iCloud. Check that by opening SilentKnight one last time.

SilentKnight confirms that all your security updates have been installed successfully. Although the Tahoe upgrade is still waiting there to catch you unawares, there’s now no Install all updates button. When you want to install individual updates such as XProtect, use the Install Named Update… command in the File menu. Paste in the Label of the update, such as XProtectPlistConfigData_10_15-5323, check that it isn’t the Tahoe upgrade, and click the Install Named Update button for each security update you want to install.

There’s one final trick you need to remember. When macOS keeps notifying you of the Tahoe upgrade, click on that notification away from its buttons to open Software Update, then close that window. That should ensure that macOS doesn’t try upgrading your Mac on the sly. If it does start downloading the Tahoe upgrade, quit all open apps and shut down. After a few seconds start up again and that upgrade should be forgotten. For a while, at least.

Following their return to the outskirts of Paris after the Franco-Prussian war and Paris Commune, Alfred Sisley, Claude Monet and Auguste Renoir had painted in and around the Monets’ home in Argenteuil on the north bank of the River Seine. Monet commuted into the city by train, the Sisleys shared their house, and Renoir visited in the summer.

Édouard Manet was another visitor, and painted this oil sketch of Claude Monet in Argenteuil in 1874, showing Monet working in his floating studio. His position in the boat appears relaxed, but would have become uncomfortable if maintained for long, as he would have had to keep bending forward to paint, suggesting he might have posed for this painting.

In 1876, Monet’s wife Camille became seriously ill, deteriorating further with the birth of their second son in 1878. The family moved to share a house with his patron Ernest Hoschedé in Vétheuil, further out to the north-west. The Sisleys moved to Moret-sur-Loing on the opposite side of Paris, leaving only Renoir to continue his summer visits.

Renoir’s The Boating Party at Chatou (1879) shows watersports taking place further down the river, with a combination of social rowing in the foreground, and two sports rowers further out in the river.

Renoir’s By the Water from about 1880 is believed to have been painted on the terrace of the Restaurant Fournaise on the Île de Chatou, which he was soon to use for his major work Luncheon of the Boating Party (below). If that’s the case, then what appears to be a lake in the background is really the River Seine.

During the summer of 1880, Renoir started work on another of his masterpieces, that he didn’t complete until the following year: Luncheon of the Boating Party (1880-81), with its complex group of figures.

This was again set on the Île de Chatou at the Restaurant Fournaise, and funded by commissioned portraits over this period. Among his models are his partner and later wife Aline Charigot (left foreground, with affenpinscher dog), the actress Jeanne Samary (upper right), and fellow artist Gustave Caillebotte (seated, lower right). This was exhibited at the Seventh Impressionist Exhibition in 1882, where it was praised by several critics.

Later in 1882, Renoir painted The Bridge at Argenteuil in Autumn, close to another bridge over the river for which Monet had a particular affection.

In 1881, Gustave Caillebotte acquired a property at Petit-Gennevilliers, near Argenteuil, where he had a boatyard, and moved there permanently in 1888. He and Renoir maintained the tradition of painting this section of the River Seine.

Caillebotte’s Boat Moored on the Seine at Argenteuil from about 1884 has thoroughly Impressionist style and facture, with its obvious brushstrokes forming the broken reflection of the boat on the water, and even detail through the depth of the painting.

Although Caillebotte didn’t make formal series of views that became such a feature of the art of Monet and Pissarro, in the mid-1880s he painted several views of the modern bridges over the River Seine near Argenteuil. The Bridge at Argenteuil and the Seine (1885) is Impressionist in style, with its broken water surface. This features a steam paddle tug towing a laden barge towards the next bridge, which I think is the railway bridge that Claude Monet painted at least twice.

In 1888, Renoir spent the summer painting at Argenteuil and Bougival, where he rediscovered his landscape form.

Renoir’s The Seine at Argenteuil from 1888 is another view of leisure boating, painted in a style more similar to Sisley’s high Impressionist landscapes, with coarse high chroma brushstrokes laid to form the surface of the water.

For Gustave Caillebotte and his friends, this was the place to come to enjoy a day’s sailing, as shown in his late painting of Sailboats on the Seine at Argenteuil from 1892, just two years before his untimely death at the age of only forty-five. With that, Argenteuil and Chatou were abandoned and Impressionism moved on.

You may have heard my deep sigh of disappointment last week when I looked through macOS Tahoe 26.1. Despite its bumper crop of 90 fixes for security vulnerabilities, as a scheduled update it has two major flaws. It is at once an opportunity ignored, and a failure to learn from history.

Liquid Glass

Ever since the first beta-release of Tahoe reached developers in June, its human interface has been lambasted like no other. Apple has had a torrent of objections to several of its new features, including the gross rounding of corners of windows and controls, its bland and indistinguishable icons, interference between overlaid content, and its uniform bleached-out tone. In those five months, there has been no shortage of suggestions as to what needs to be improved.

Apple’s response is a Liquid Glass control in Appearance settings that purports to provide a “tinted” variant that “increases opacity and adds more contrast”. As I demonstrated early last week, it does neither, and in Light mode in the great majority of Apple’s own apps, this “tinted” variant doesn’t make a blind difference.

Above is Light mode, Liquid Glass set Clear, without Accessibility. Below is the same, but with Liquid Glass set to Tinted.

After many attempts to find some difference between Clear and Tinted in the bundled apps I use most often, I’ve decided that they are visually identical. And where the Liquid Glass effect results in optical interference between layers, Tinted doesn’t alter opacity to eliminate that interference.

This is illustrated in the defaced search box at the top left of System Settings, where the blurred contents of the navigation sidebar at the left remain visible underneath the window’s search box. I can’t understand how any designer could see that released to the public, and providing the new Liquid Glass setting is farting into a hurricane.

Background Security Improvements

Although Apple went out of its way not to let us know, I’m actually glad to see the return of Rapid Security Responses (RSR), even if they’ve been given this sanitised name. What disappoints me deeply is that the BSI shows no sign that Apple has learned from its past mistakes with RSRs just over two years ago.

RSRs, which have never been officially declared dead, were downloaded through Software Update, and gave the user the choice of installing them automatically, downloading and installing them when they chose to, or ignoring them and waiting for the next macOS update. Not only that, but once installed, they could be removed and macOS reverted to its previous state.

What Apple never did get right is how to number the macOS version once an RSR had been installed. Rather than extend version numbers consistently with a fourth digit, Apple decided to append a letter in parentheses, making 13.4.1 become 13.4.1 (a) when its first RSR had been installed. When the first RSR was released on 1 May 2023, Safari’s build number was changed, but not its version number. But with the second RSR on 10 July, someone mistakenly changed Safari’s version number from 16.5.1 to 16.5.2 (a), and that was therefore given as its User Agent, and promptly broke many major websites including Facebook.

Because that RSR could be removed by the user, there was an immediate solution, and Apple delivered a revised RSR a couple of days later.

From this, we learned that:

• RSRs undergo very little testing before release, as they’re supposed to be issued quickly.
• Because they undergo such little testing, their chances of significant incompatibilities are greater.
• Giving the user the option to delay installing an RSR saves many from being caught out by flawed RSRs.
• Giving the user the option to uninstall an RSR is essential in the event that one proves to be flawed.
• Knowing when an RSR is being installed is essential if users are going to be able to identify the cause of problems arising from them.
• Numbering of macOS versions needs to be restructured to accommodate RSRs.

Now, over two years later, it seems Apple has forgotten those lessons. It won’t even describe these as security updates, but “improvements”, won’t include them in the release notes for 26.1, hides their single control at the very bottom of a long list in Privacy & Security settings, rather than in Software Update, provides no manual option, and no means to uninstall them.

I wonder how long it will be before we all regret those decisions, and have to repeat past mistakes before we can learn from them.

When the French Impressionists reassembled after the Franco-Prussian War and the Paris Commune, they gathered a little further up river from Louveciennes and Bougival, at the small town of Argenteuil on the north bank of the River Seine. At the time it was just on the outer edge of the north-western suburbs of the city, about 12 km (7.6 miles) from the centre, and was only fifteen minutes by train to the Gare Saint-Lazare in Paris. Claude Monet was able to commute into the metropolis, and the Sisleys moved in with the Monets in 1872. This weekend I show a small selection of the best-known paintings that were made in and around Argenteuil, and particularly at Chatou, down river.

Although Monet was barely making a living from his art at this time, he was among the few who could afford to use cadmium yellow, which has been found in his painting of The Artist’s House at Argenteuil from 1873.

This marked the start of a highly productive period for Alfred Sisley, and, in conjunction with Monet and Renoir, changed his art. The three concentrated their efforts on the recording of transient effects of light using colour, removing black from their palettes, and abandoning the traditional ‘finish’ of their paintings.

Sisley’s Footbridge at Argenteuil from 1872 is dominated by the perspective projection of the bridge itself, almost to the exclusion of the river below. His figures are gestural but look natural in their forms.

The Impressionists occasionally painted themselves at work, particularly during the earlier years of the movement. Above is Pierre-Auguste Renoir’s Monet Painting in his Garden in Argenteuil from 1873. He is using a conventional lightweight wooden easel, with a small canvas allowing him to work standing, with his oil paints in the pochade box under the easel.

Monet’s The Railway Bridge at Argenteuil (1873) is one of his several landscapes centred on the railway from the years immediately after the Franco-Prussian War. The following year, he painted the same bridge, as seen below in The Railway Bridge at Argenteuil (1874).

Monet’s commute ended at the Gare Saint-Lazare in Paris, where in 1877 he obtained permission to paint a series of works showing the station. By the third Impressionist Exhibition of April of that year, Monet had assembled seven views of the station, including one that even seemed to please the critics. Among the paintings from that campaign is his Arrival of the Normandy Train, Gare Saint-Lazare (1877).

One of the products of Renoir’s painting with Monet was this highly chromatic view of The Duck Pond (1873) at a farm near Argenteuil.

The following summer, Renoir visited Argenteuil again, to paint in the company of both Monet and Manet. The Seine at Chatou (1874) is one of his more vigorously crafted works, with a water surface similar to those being painted at the time by Sisley.

Monet’s masterwork Autumn on the Seine, Argenteuil from 1873 is a textbook example of a river landscape in autumn painted in high Impressionist style, with high chroma and loose brushstrokes.

Here are this weekend’s Mac riddles to entertain you through family time, shopping and recreation.

1: Black leopard exposé of 2003 could fax.

2: Officially a 750, it brought the fastest notebook in the world in 1997.

3: Came with a plus, bulging trash and SCSI.

To help you cross-check your solutions, or confuse you further, there’s a common factor between them.

I’ll post my solutions first thing on Monday morning.

Please don’t post your solutions as comments here: it spoils it for others.

Loose words confuse, and one of the words used most loosely in macOS is permissions. This explainer tries to separate them from other access controls.

Permissions

The access permissions of files and folders are set in their attributes in the file system, stay with that item, and are applied universally for all apps and processes that try to access them.

The simplest and most basic of access controls, these can be inspected and changed in the Finder’s Get Info dialog for all accessible files and folders. They control the ability of apps and other code to read from and write to each file and folder. Normally, if you’re the named owner of a file or folder, you expect to have both read and write access, and that ensures the apps you run with user privileges can open, edit and save changed files.

Permissions are relatively crude controls, so Access Control Lists (ACLs) can refine those permissions with more specific restrictions. They were introduced in Mac OS X 10.4 Tiger in 2005, and are now applied as standard to some widely used folders including the Home folder. The presence of ACLs is normally indicated in the Get Info dialog by the words You have custom access.

No matter what security controls and privacy protection might give you access to, they can’t override the fundamental limits imposed by permissions, and can only limit access further.

Security controls

The macOS security system imposes its own controls according to its rules. Most obvious among those are System Integrity Protection (SIP) and sandboxing.

SIP was introduced in 2015 with El Capitan, and primarily puts system folders, files and some components, including certain extended attributes, beyond the reach of even the root user. The only way to get past SIP is to disable it, a serious undertaking as it has more general effects on security.

Sandboxing is security protection that limits the files individual apps can access by imposing a sandbox as set by their entitlements. It’s therefore determined by the app trying to access files, and doesn’t apply to apps that don’t run in the sandbox. As an app’s entitlements are baked into its signature, there’s nothing a user can do to alter them.

Privacy protection

macOS designates certain locations and resources as being private, and protects them using its Transparency, Consent and Control (TCC) system. Although it has a longer history, this was first implemented in its current form in macOS 10.14 Mojave in 2018, and since then has grown with every new major version of macOS. Privacy protection operates outside of file attributes, using a rule-based system applied to each app, and applies to command tools and other processes as well.

Among the folders this protects are the Desktop, Documents, Downloads, and those on removable storage. While access to individual folders is controlled, if you do encounter problems it’s usually simplest to add that app to the list of those with Full Disk Access, in Privacy & Security settings, in the first instance. That can leave a lot of apps with unnecessary access to private data, so you should periodically check through the list of apps with Full Disk Access to ensure they all still require it. Remember that Full Disk Access can’t override restrictions imposed by permissions or ACLs.

In Tahoe, privacy-protected folders include:

• ~/Desktop
• ~/Documents
• ~/Downloads
• iCloud Drive
• third-party cloud storage
• removable volumes
• network volumes
• Time Machine backups.

Unlike permissions and security controls, there’s no command line interface to these controls, which can only be accessed by the user in Privacy & Security settings. As a result, TCC uses an attribution chain that traces up through the call chain to an app that is responsible for the privacy settings to be applied. For example, when you run commands in Terminal, the privacy settings used by TCC are those of the Terminal app, while helper apps are normally the responsibility of their parent app.

Privacy protection is built around the user’s consent and intent. When a process tries to save a file to a protected folder that it doesn’t already have access to, you should be prompted to give your consent before TCC allows that. Alternatively, when an app tries that, it should display the File Save dialog, where you can express your intent to save the file to that folder. Without consent or intent, TCC should block that file from being saved there unless that app has been given Full Disk Access in Privacy & Security settings.

Privacy protection is the most complex and opaque of these, and can present the toughest problems to solve.

Key points

• Permissions by attributes
• Security by security system
• Privacy protection by TCC, the app and rules
• Loose words confuse.

Artists seldom painted the interior of their studio until the nineteenth century, and it was unheard of in the Renaissance. So when you’re offered a glimpse into that of Sandro Botticelli in the 1480s you’d be justifiably suspicious, particularly when it wasn’t painted until 1922, over half a millennium later.

Nevertheless, almost exactly eleven years ago, on the fifth of November 2014, a remarkable painting claiming to depict Botticelli’s studio at that time was auctioned in New York. Captured on its canvas were the faces of those long dead, those of the artist and members of the Medici family.

The painting’s title reveals its key figures: Botticelli’s studio: The first visit of Simonetta presented by Giulio and Lorenzo de Medici (1922). The artist stands at the left in front of an exquisite tondo he is working on. Bowing to him at the centre is Giuliano de’ Medici, who is accompanied by Simonetta Vespucci, wearing the green dress. Behind her is Lorenzo de’ Medici, also known as Lorenzo the Magnificent, and behind him are Giovanna Tornabuoni and her attendants. The view through the window is of the Palazzo Vecchio in the centre of Florence.

Painted by the British artist Eleanor Fortescue-Brickdale, those figures weren’t based on models or imagination, but on contemporary sources.

Giovanna Tornabuoni comes from a detail of Domenico Ghirlandaio’s painting The Visitation (c 1488) in the Tornabuoni Chapel of the Church of Santa Maria Novella in Florence. Giovanna was born as Giovanna degli Albizzi in 1468, married Lorenzo Tornabuoni in 1486 when she was about eighteen, and died in childbirth two years later in 1488. She is here accompanied by her maid and nurse.

Lorenzo de’ Medici (1449-1492) hails from Girolamo Macchietti’s undated portrait of Lorenzo the Magnificent. Lorenzo was born in 1449 into the banking family, the grandson of Cosimo de’ Medici, at the time one of the wealthiest and most powerful people in Europe. Lorenzo was groomed for power, and became de facto ruler of the Florentine Republic when his father died in 1469.

He survived an attempted assassination in the Cathedral of Santa Maria del Fiore on Easter Sunday 1478, in which his brother Giuliano was stabbed to death. This led to his excommunication, and invasion by forces of the King of Naples. He resolved that, and died in 1492, when he was forty-three.

Botticelli also painted this Portrait of Giuliano de’ Medici in about 1475. Giuliano was born in 1453, younger brother and co-ruler of the Florentine Republic with Lorenzo. He was brutally murdered in that attack in the cathedral on Easter Sunday 1478, dying at the age of twenty-five. Although he never married, an illegitimate son of his became Pope Clement VII.

The painting shown in progress is Botticelli’s Madonna of the Magnificat, thought to have been completed in 1483. It shows the Virgin Mary being crowned by a pair of angels, writing down the start of the Magnificat in a book, and holding a pomegranate in her left hand. It has also been interpreted as a family portrait of the de’ Medicis, in which the Virgin is Lucrezia Tornabuoni, the mother of Lorenzo and Giuliano de’ Medici, who are the angels. I believe that Lucrezia was one of Giovanna Tornabuoni’s aunts by marriage.

The source of the likeness of Botticelli is more of a problem, as he isn’t known to have painted a formal self-portrait. It’s generally believed, though, that he revealed himself in cameo in this detail from his The Adoration of the Magi from about 1475.

It’s also thought that Filippino Lippi included his portrait in this section he painted in 1483-84 of Massaccio’s incomplete fresco in the Cappella Brancacci, Santa Maria del Carmine, Florence, in Disputation with Simon Magus and Crucifixion of St Peter.

But of all the figures shown in this painting, Simonetta Vespucci is the most fascinating. She was born Simonetta Cattaneo in 1453, and when she was only fifteen or sixteen, she married Marco Vespucci, cousin of Amerigo Vespucci, the first to demonstrate that the New World of the West Indies and Brazil wasn’t part of Asia.

Once married, she lived with her husband in Florence, where she was a great favourite at the court of the de’ Medicis. Giuliano de’ Medici entered a jousting tournament in 1475 bearing a banner with an image of Simonetta as Pallas Athene, painted by Botticelli. She had the reputation of being the most beautiful woman in the whole of northern Italy, but that beauty was fleeting as she died of tuberculosis in 1476, when she was only twenty-two.

Many paintings have been claimed to be portraits of her, but perhaps the most credible is Piero di Cosimo’s Portrait of Simonetta Vespucci from 1490.

Several of Botticelli’s works have been claimed to feature figures for which Simonetta modelled, even the naked Venus in his famous The Birth of Venus (1484-86). The least unlikely might be his Idealized Portrait of a Lady, also known as Portrait of Simonetta Vespucci as Nymph, thought to have been painted in 1480, four years after her death. Such portraits were commonly not true to life, but idealisations intended to flatter rather than identify, so we will never know if she was its subject.

Inevitably, time in Botticelli’s studio is slightly out of joint. The figures might have been able to gather together in this way in about 1475, before the deaths of Simonetta and Giuliano de’ Medici, but that is well before Botticelli might have painted Madonna of the Magnificat, and when Giovanna Tornabuoni was still a child.

This remarkable painting was the second of its kind by Eleanor Fortescue-Brickdale.

Two years previously, in 1920, she had painted The Forerunner, showing Leonardo da Vinci trying to convince the Milanese court of his idea for flying machines. Notable figures included here are (from the left) Savonarola (from Fra Bartolomeo’s portrait), Beatrice d’Este (Duchess of Milan), Cecilia Gallerani, Elisabetta Gonzaga, Leonardo da Vinci, and Ludovico Sforza (Duke of Milan, and Leonardo’s patron).

Eleanor Fortescue-Brickdale sold The Forerunner to Lord Leverhulme, and it is now on view in the Lady Lever Art Gallery. She was subsequently commissioned to paint Botticelli’s Studio in 1922 for Montague Rendell. That was shown at the Royal Academy later that year, and has been in a succession of private collections since.

Diagnosing problems using the Unified log is a complicated business that requires understanding, insight, experience and a systematic approach. As few of us feel competent to wade through thousands of log entries trying to spot where things go wrong, this might seem an ideal opportunity for the use of AI. I’m very grateful to one of our regular readers for the opportunity to demonstrate how Claude coped with diagnosing a troublesome problem they’ve been having with the Clock app in Tahoe.

Signs and symptoms

When you’re diagnosing any problem, you should start with a clear account of its signs and symptoms before even thinking of resorting to the log. A good physician may take an hour or more obtaining a full history and examining a patient before they start thinking about performing any special investigations. Even though signs and symptoms may not lead you to a diagnosis, they should help you direct your investigations to best effect.

In this case, although the Clock app is launching, when displaying some views the content is missing. We therefore agreed to capture the log from the moment of launch from the Finder until one of the problematic views displayed. That’s easy to achieve by double-clicking the app when the menu bar clock has just turned to display 00 seconds, then checking the time again when the view has been displayed. Add a couple of seconds to the latter to determine the period to view in LogUI.

What’s normal?

Recognising what’s abnormal in the log is only possible if you know what the normal looks like. It’s often perfectly normal to see error messages, but knowing which are relevant is more difficult. In this case, I cheated and obtained a matching log extract from launching the Clock app on another Mac running the same version of Tahoe, making it simple to compare the two.

An interesting exercise for the reader is to submit a perfectly normal log extract to AI, with a vague description like “problems starting the app”, and seeing if it reports that as being normal. I doubt that it would.

Preparing a log extract for submission to AI

LogUI can provide log extracts saved to Rich Text Format, preserving the entry fields, although I doubt whether any AI will be able to interpret those correctly. Perhaps the best route is to save the extract in RTF, and save that in turn as plain text. A longer way round is to:

• Save the whole extract as a JSON file, to preserve the whole record.
• Use the Search tool to display the entries you want to submit for analysis.
• Click on the Reduce tool to remove the unwanted entries.
• Save the remaining entries in Rich Text, then save that in plain text format.

That also allows you to submit a shorter extract.

Claude’s report

AIs like Claude are thoroughly professional in their reporting, even when they’re utterly incorrect. In this case, Claude’s report is headed Complete Analysis of the Problem, and appears a confident and detailed assessment presented logically. It first establishes:

• The App DOES Launch Successfully
• Main Issue: Continuous Assertion Invalidation
• Infinite State Loop
• Critical Errors Identified

supporting those with digested “quotations” from the log, although in fact most of them are rendered in Claude’s words, not those in the log entries themselves.

It then leaps on to give the Final Diagnosis that the Clock app:

• Launches
• Creates its scenes and interfaces
• Registers functionalities (alarm, stopwatch, timer)
• Fails to maintain the assertions necessary to remain active
• The system continuously invalidates its resource requests.

Those are embellished with appropriate and emoji.

Following those conclusions, it cites what it terms Key Log Evidence in support of that diagnosis. Among those are the following.

Critical Error at Launch

For this, it quotes part of the message from
00.968273 error com.apple.runningboard [app[application.com.apple.clock.1152921500311884024.1152921500311884029(501)]:1921] Memorystatus failed with unexpected error: Invalid argument (22)
and a similar entry.

However, it doesn’t point out that those are rapidly followed by
00.969966 com.apple.runningboard [app[application.com.apple.clock.1152921500311884024.1152921500311884029(501)]:1921] set Memory Limits to Soft Inactive (800)
00.970684 com.apple.launchservices LAUNCH: Successful launched 0x0-0x3b03b pid=1921 com.apple.clock '[private]'
which would appear to contradict this being a “critical error”.

Kernel Warning

Claude’s report next misquotes one of the log entries as reporting
Clock[19237] triggered unmask of range (1 of 16384:0000->0x1ce000000 of DVLD shared region in VM map 0x5c946dd8d4c72dbbf
when in fact the full entry reads
10.891949 kernel Clock[19237] triggered unnest of range 0x1e8000000->0x1ea000000 of DYLD shared region in VM map 0x5c946da0d472dbbf. While not abnormal for debuggers, this increases system memory footprint until the target exits.
It gives no reason for changing unnest to unmask, DYLD (which makes sense) to DVLD (which is nonsense), or changing the range given.

For interest, I used LogUI’s Gloss feature to submit that entry to ChatGPT for its explanation:
This log entry is a system notice from the kernel indicating that a portion of the DYLD shared region in the virtual memory (VM) map has been unnested. […] In short: The macOS kernel is reporting that the process Clock caused a part of the shared dynamic library cache to become private memory. This is expected behaviour when certain debugging or memory operations occur, but it will temporarily use more RAM until the process exits.

Continuous Assertion Cycle and Scene Management Loop

Claude then claims that the perfectly normal entries made by RunningBoard and FrontBoard demonstrate a continuous assertion cycle and scene management loop. Anyone who has read my account of RunningBoard would realise that is a misreading of what is both common and normal.

Claude’s Possible Solutions

Nearing the end of the report, Claude recommends four possible solutions:

• Reset system permissions: sudo tccutil reset All com.apple.clock
• Rebuild launch services cache: /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user
• Verify system integrity: sudo /usr/libexec/repair_packages --verify --standard-pkgs
• If everything fails: This could be a specific bug in macOS Tahoe with the Clock app that requires a system update.

The first is misleading, as TCC has nothing to do with system permissions, but privacy controls. Although Claude has made no comments at all on entries by TCC, I have checked through those thoroughly and there’s no evidence of any problem with that subsystem. The command recommended isn’t likely to do anything useful, either.

Despite Claude having provided no evidence of any problem with LaunchServices, its second solution is to perform a full reset of the LaunchServices registry (not cache), although I’m not sure the command given is correct for that. This used to be a popular panacea in the past, but is now more trouble than it’s likely to be worth. The last time I reviewed this for Sequoia, I wrote:
“Running either of those in recent versions of macOS including Sequoia is likely to wreak havoc, though. While this appears to be effective with the Open With… list, its effects on System Settings can be catastrophic. This can remove its entire contents, and even blow the wallpaper away. Normal function should start to return after restarting the Mac, but even then problems can persist.”

Yet Claude gives no warnings of any adverse effects.

The third solution given is the most puzzling. repair_packages was used to repair System permissions in versions of macOS up to El Capitan. It hasn’t been used since, makes no sense at all in Tahoe with SIP and the SSV, and that command no longer exists anyway. I find it surprising that Claude should be recommending a course of action from ten years ago.

The final recommendation is manifestly ineffective, as this problem has persisted across updates from 26.0 to 26.0.1 and now 26.1.

Nowhere does Claude recommend the obvious course of action to contact Apple Support.

Claude’s Summary

The slick summary rounding off Claude’s Complete Analysis of the Problem states confidently that its root cause “appears to be either:”

1. “A system-level bug in macOS Tahoe’s memory status handling for this specific app”
2. “Corruption in the app’s entitlements or sandbox configuration”
3. “A conflict between the app’s resource requirements and what the system is willing to grant”

with the parting comment:
The error code 22 (EINVAL – Invalid argument) in the memorystatus call suggests the app is requesting memory limits or priority settings that the kernel considers invalid for its configuration.

None of those comments is supported in reality, nor by the evidence in the log extract.

My final test was to compare the log entries that Claude singled out as being diagnostic of the problem it has ‘completely analysed’, with those from my Mac mini M4 Pro, whose Clock app works perfectly. You won’t be surprised to learn that, in those respects at least, the two logs are identical. For the avoidance of doubt, that includes the “Kernel Warning” and “Critical Error at Launch” entries that Claude considered diagnostic.

My Summary

When presented with a log extract, Claude misidentified and misread log entries, and introduced errors in reporting what it claimed were the most important diagnostic entries. Its recommended solutions were ineffective, unwise, or a decade out of date. Neither did it give any warnings for their adverse effects, or recommend contacting Apple Support.

This doesn’t say that AI can’t help interpret macOS Unified log entries, and can’t do better in the future. But I hope it demonstrates the reality of what it will do today.

Postscript

Following up on Claude’s suggested solutions, I can confirm that the suggested tccutil command is ineffective, and that Tahoe has removed the -kill option from lsregister “because it was dangerous and no longer useful”. As the third solution was removed years ago, that leaves only the last of its suggestions that is valid.

Sirens are mythical woman-like creatures with alluring voices, best-known from their appearance in Homer’s Odyssey, but also featuring in other tales including that of Jason and the Argonauts. Typically their singing lures sailors to their death, and that reputation has led them to represent anything that’s dangerously attractive. Originally they weren’t described in any physical detail, but visual representations soon envisaged them as having the upper bodies of beautiful young women, and the lower bodies and legs of birds, and that has been incorporated and elaborated in later accounts and retelling.

At the end of the year that Odysseus and his crew stayed with the sorceress Circe, she helpfully advised him that he would have to sail past the sirens, two to five creatures who lured men to their death with their singing. In preparation, Odysseus got his sailors to plug their ears with beeswax before they reached the sirens, so they couldn’t hear their song, and to bind him to the mast. He gave them strict instructions that under no circumstances, no matter what he said at the time, were they to loosen his bonds, as he would be listening to the sirens’ song.

As the group reached the sirens, Odysseus told his men to release him, but instead they bound him even more closely to the mast. Once they had passed safely from earshot of the sirens, Odysseus used his facial expression to inform his men, who then released him, and they sailed on.

William Etty’s The Sirens and Ulysses from about 1837 is one of the pioneering accounts in paint of this story from the Odyssey. His three naked sirens are all woman, one playing a lyre, another holding double pipes aloft, all three doing their best to draw the sailors from Odysseus’ ship to a shore where there are the remains of earlier victims.

Edward Poynter’s The Siren from about 1864 has Aesthetic overtones in the lyre she is playing.

Arnold Böcklin takes an unusual approach of almost dereferencing Odysseus in his painting of Sirens from 1875, although there is an approaching vessel that could be his. The two sirens filling the canvas are very human down to the waist, below which they resemble birds. One sits facing us, clearly in full voice, and highly alluring in looks. The other, her back towards us, is playing an aulos and looks rather obese, to the point of almost being comical, her right breast laid upon a flat-topped rock. At their feet are three human skulls and other bones to indicate their graver intentions.

Gustave Moreau’s The Sirens (1882) shows them as beautiful figures in a static scene, with a saturnine setting sun. There is, though, a lone sail on the horizon that hasn’t yet attracted their attention. Their lower legs turn into the writhing coils of sea serpents.

Moreau’s slightly later group portrait of The Sirens from about 1885 is more complete, with Odysseus sailing past, but its three figures are clearly all woman and no bird.

Eight Dancing Women with Bird Bodies (1886) is one of Hans Thoma’s unusual mythological paintings. The best-known women with bird bodies were the sirens, who range in number from two to five. In another painting showing the sirens trying to lure a passing ship, Thoma paints similar figures, suggesting these are intended to be sirens.

John William Waterhouse’s Ulysses and the Sirens (1891) is closer to the Homeric account, although he provides a total of seven sirens, shown as large eagle-like birds of prey with only the head and neck of beautiful women. He has added bandage wrappings around the head of each sailor to make it clear that their ears are stopped from hearing sound, a visual device that links neatly with the text. His sirens are clearly singing, particularly the one closest to the viewer, who is challenging the hearing protection of one of the sailors. Another sailor, at the stern of the ship (left of the painting), is seen clutching his ears.

Almost a decade later, Waterhouse painted this non-narrative portrait of The Siren (1900).

The Sirens (1903) marked Henrietta Rae’s return to painting narrative works featuring classical nudes. Odysseus’ ship is in the distance, as three beautiful sirens use their aulos and lyre to lure its occupants.

Late mythology suggests an unpleasant end for these sirens: Hera challenged them to a singing contest against the Muses. When the latter won, the penalty they exacted of the sirens was to have all their feathers plucked out to turn into crowns. As a result of that disgrace, the sirens turned white, fell into the sea, and formed the islands including modern Souda, on the north-west coast of Crete in the Mediterranean.

Sirens have steadily spread their presence into other paintings, particularly during the twentieth century.

Georg Janny’s fantasy painting of Sirens Bathing by the Sea from 1922 is throughly other-worldly, and there’s no trace of their bird legs.

More cryptic is Paul Nash’s Surrealist Nest of the Siren (1930), which brings together the incongruous, and hardly refers to Homer’s story. The painting is framed by brightly-painted walls with pillared decorations, perhaps ornate wainscot panelling. In the middle of these is what might be a painting, but also seems to be a three-dimensional plant trough containing sinuous shrubs. In the middle of those is a small nest, like an acorn cup.

Standing in front of this is a structure resembling a weather-vane, mounted on a turned wooden shaft. At the weather end of the vane is the faceless figure of a siren; the leeward end appears purely decorative. Three red rods appear to have detached themselves from the walling, two protruding from the plant trough, the third resting on the floor.

They even manage to sneak symbolically into other classical stories.

In Girodet’s ink and chalk drawing of The Meeting of Orestes and Hermione (c 1800), Hermione is seen at the right, her arms folded, looking coy as Orestes approaches her. The second woman, with Orestes, is presumably Hermione’s maid. This is one of a series of illustrations made by Girodet to accompany Racine’s play, and has subtleties you might expect from a great narrative artist. Visible in the gap between the figures is a table-leg in the form not of a Fury foretelling Orestes’ fate, but of a siren, implying that Hermione is luring Orestes to her. Hermione, for all her apparent coyness, has let the right shoulder-strap of her robe slip, in her enticement of Orestes. She has assumed the role of femme fatale, as portrayed by Euripides and Racine.

In more recent literature, sirens appear in the less-known second part of Goethe’s play Faust.

Margret Hofheinz-Döring is one of the few artists who has painted from this second part. With the Sirens from 1962 is her pastel painting showing the sirens among rocky inlets of the Aegean Sea, a sub-scene concluding the second act.

If you have updated your Mac to Tahoe 26.1, you may be blissfully unaware that it will now automatically download and install some security updates, regardless of its Software Update settings. Open Privacy & Security settings, scroll down to the end and you’ll see a new item, Background Security Improvements, that Apple has kindly turned on for you. There are matching new settings in iOS and iPadOS 26.1 that are also enabled by default.

Apple seemingly forgot to mention these when listing the changes in 26.1, and its documentation of these Background Security Improvements (BSI) is sketchy to say the least. However, the description there as “lightweight security releases for components such as the Safari browser, WebKit framework stack and other system libraries” is so similar to that for RSRs as “improvements to the Safari web browser, the WebKit framework stack, and other critical system libraries” that we can only conclude the BSI is a rebranded RSR.

What is an RSR/BSI?

Although almost all of macOS is contained in the System volume, turned into a snapshot that’s protected by a tree of hashes with a signature, then mounted as the Signed System Volume, there are additional components that are delivered in separate cryptex files. These are also heavily protected with signatures to verify their contents, and are mounted well after the kernel has booted. APFS then grafts them into the root file system so their contents appear in the correct places. There are currently two main cryptexes common to all Macs, one containing Safari and its WebKit components, the other with dyld caches supporting frameworks. Apple silicon Macs additionally have many smaller cryptexes to support AI and related features.

Because those cryptexes are separate from the SSV, they can be unloaded, replaced with updated versions, and reloaded without necessarily having to reboot the kernel, or go through any of the complex procedures to update macOS itself. Apple first tested this new type of update, a Rapid Security Response (RSR), in beta-releases of macOS 13 Ventura, and the first was publicly released for Ventura 13.3.1 on 1 May 2023.

How do RSRs work?

RSRs have been released using the regular Software Update mechanism, controlled in its settings, and can be uninstalled manually even if you have opted for them to be installed automatically.

To remove an RSR, you open System Settings > General > About, and look down for the macOS version. At the right of that line is an ⓘ button: click on it to see the dialog above, allowing you to uninstall it.

Why don’t we get RSRs now?

Apple proudly announced RSRs at WWDC in June 2022, and they were listed among the new features in Ventura: “Get important security improvements to your devices even faster. This isn’t a standard software update. These improvements can be applied automatically between normal updates — without a restart.”

Although the first in May 2023 seemed to go well, the next on 10 July was an embarrassing disaster. RSR 13.4.1 (a) fixed one WebKit vulnerability, but unfortunately it also changed the version number of Safari to 16.5.2 (a), which was reflected in its User Agent, so broke access to many popular websites including Facebook. That had to be rectified in RSR 13.4.1 (c) released three days later. And all three of these RSRs required the kernel to be rebooted after their installation.

Since then, as far as I’m aware, Apple hasn’t released any further RSRs, although they’ve still been referred to throughout its documentation.

Their greatest limitation is that they can only fix vulnerabilities that are confined to Safari, WebKit and other components that are delivered in cryptexes. More commonly, urgent security patches also require changes to software in the SSV, for which the only solution is a full update. For example, during the year that macOS Sequoia was current, it received six patch updates in between those scheduled. Of those, only two might have been suitable as RSR/BSI updates, as all the others required changes to the SSV.

How do BSIs work?

If Apple’s current account of BSIs is complete, the only control we have over them is whether they’re downloaded and installed automatically. If you opt for that, as Apple has set as the default, then you won’t be given any warning, or even informed when the BSI has been installed on your Mac. The only way you’ll be able to learn that is by trawling through the list of software installations in System Information, although Apple will post information about the BSI in its security release notes, following its release.

If there’s a problem with a BSI, such as that in the second RSR in July 2023, then there’s no option to uninstall the BSI and revert to a previous version of that cryptex, as there was with RSRs. However, Apple might decide to remove the BSI from your Mac.

Given the short and unfortunate history of RSRs, that might appear surprising.