Earlier in this series, I showed an example of the origin of all modern paintings in the decorated caves of pre-history. As shelters became buildings, our ancestors continued to paint their walls, using a technique now known as secco wall or mural painting, where wet paint is applied to dry stone or plaster.

Secco has been widely used outside Europe, and can still be seen in some very old European wall paintings, such as those in Braunschweig Cathedral, including Christ Pantocrator, thought to date from the early thirteenth century. Long before that was created, though, wall painting advanced to improve adhesion between its paint layer and ground. In secco technique, only thin layers of pigment can be used, resulting in weak colours, little detail, and the need for periodic re-painting as pigment is gradually lost over time.

Artists experimented with different binders and secco techniques. Although dry plaster is more absorbent and a better ground than bare stone, success has been limited, and failure a constant danger. At some time before about 1700 BCE, one of the Mediterranean cultures discovered that it was possible to apply paint onto a layer of wet plaster, and the technique of fresco (strictly, buon fresco) was born.

The Romans loved frescos that made their rooms look as if they were in a spacious outdoors, like this from the House of the Golden Bracelet in Pompeii.

In fresco, the support remains the wall or ceiling of the building, but the ground is absorbent wet plaster applied to that surface. Pigment is diluted in water and applied directly to the ground while the latter is still wet; this allows the paint to be absorbed into the ground, providing good and durable bonding of the pigment. Plaster is made using lime, derived from crushed limestone, and sets by reaction with carbon dioxide in the air to form calcium carbonate (from which both chalk and limestone are composed) and water, which evaporates during drying.

Techniques became even more refined, with the use of additional layers of plaster prepared in specific ways, to which red pigment sinopia might be added, allowing the artist to draw construction and other lines to assist in final painting. Because these frescos are on a grand scale, transferring the design of a painting from final sketch to the wall or ceiling is also a challenge.

The central problem for the painter is that, to be successful, fresco has to be painted onto the plaster when it is still wet. That means only a limited area can be plastered and painted each day, known as giornate (singular giornata), a day’s work. For all but the smallest of ground-level fresco paintings, work has to be undertaken at height, from a scaffold, posing the very real risk that the artist would fall, or the scaffolding fail. Many fresco painters have fallen at work, some suffering serious injuries or death as a result.

Despite all these practical difficulties, some of the most important European works of art are frescos painted during the Renaissance in places of worship with their high walls and ceilings.

Masaccio’s magnificent fresco of The Holy Trinity in the Basilica of Santa Maria Novella in Florence, was painted in 1426-28. At the outset he would have made a preliminary plan including his giornate starting at the top and working downwards. Once ready to start the painting, a team of carpenters will have erected wooden scaffolding to give the artist and his assistants access to the whole of that section of the wall, to the full height of over six metres (21 feet). The first stage would then have been completed by assistants, who laid a rough under-layer of plaster known as the arriccio over the whole wall, and left it to dry for several days. This layer often contains abrasive sand particles to provide a key for the final layer of plaster.

Once that had dried completely, Masaccio and his assistants transferred the drawings onto the surface of the arriccio. This may have been performed by scaling up from the squared drawing and painting with sinopia, or full-size drawings may have been pricked to make holes in the paper and a bag of soot banged against the sheet held against the wall, a technique known as pouncing. Masaccio is known to have used both techniques, and may well have used each in different sections of this work.

On each day of painting, assistants would prepare the colours by mixing pigments in water. The day’s supply of plaster, the intonaco, is then prepared by mixing water with lime. That day’s giornata is covered with a thin layer of intonaco, and about an hour later Masaccio started painting into it. He then had about eight hours before it dried and he could apply no more fresh paint. Like many of the best fresco painters, Masaccio extended his painting time by using paint mixed with milk or casein and a little lime, effectively a lime-based casein medium, which could be laid onto dry intonaco.

The geometric requirements of this painting also merited special measures. When the intonaco was first applied, it was marked to indicate key construction lines, such as those in the barrel-vaulted ceiling, and down the pillars at the side. The remains of these incised lines are still visible when the fresco is viewed in raking light. In this case, there is evidence that Masaccio used lengths of string attached to a nail sunk at the vanishing point of the linear projection, below the base of the cross.

Although we think of frescos as being fixed, this one has now been moved twice within the same church, which hasn’t helped its appearance. During conservation work and movement of Masaccio’s painting in the 1950s, the opportunity was taken to study its construction. Leonetto Tintori drew up a plan of all the identified construction lines and edges of giornate; I have sketched in the latter from a reproduction of a drawing made at that time, which has since been destroyed.

It’s estimated the whole painting would have required some 24 giornate, although because of the long history of damage and attempts at its restoration, that number remains flexible. Assuming that Masaccio painted six days a week, that would have required a minimum of four weeks working for at least ten hours each day. Fresco painting doesn’t permit easy alterations either: if any repainting was required and couldn’t be accomplished using dry technique, that day’s giornata would have to be removed, replaced and repainted.

Giornate can sometimes become obvious over time, as shown in Giotto’s fresco in the Scrovegni Chapel in Padua, Italy.

Perhaps the most famous fresco is Michelangelo’s The Last Judgement (1536-41) in the Sistine Chapel of the Vatican. It covers an area of 13.7 by 12 metres (539 by 472 inches), and took over four years to complete.

In the eighteenth and nineteenth centuries, fresco became relatively neglected.

Some new frescos were commissioned for places of worship and other public buildings, and in the early nineteenth century Johann Friedrich Overbeck painted a series telling the story of Torquato Tasso’s epic Jerusalem Delivered, in the Casa Massimo in Rome. There are similar series showing Dante’s Divine Comedy and other long narratives, which are particularly suited to the medium.

In 1845, the Scottish artist William Dyce was invited to paint frescos for the Royal Family, for which he travelled to Italy to learn technique. On his return in 1847, he painted this curious composition in Queen Victoria and Prince Albert’s new and luxurious holiday palace of Osborne House, at East Cowes, on the Isle of Wight. Neptune Resigning to Britannia the Empire of the Sea (1847) is an impressive fresco, and remains in pristine condition at the top of the main staircase in the house.

Frescos have continued in religious painting, with artists such as Sergei Fyodorov painting them in churches and cathedrals, and for the occasional trompe l’oeil. John Dixon Batten’s The Creation of Pandora was painted anachronistically in egg tempera on a fresco ground by 1913. Batten was one of the late adherents of the Pre-Raphaelite movement; this painting was deemed unfashionable in 1949, and was put into storage and quietly forgotten until its rediscovery in 1990.

New frescos are still painted in some public buildings too. This work by Finnish painter Akseli Gallen-Kallela is one of a series he painted in the National Museum of Finland in Helsinki in 1928, but most other wall paintings of the twentieth century, such as those of John Singer Sargent in public buildings in Boston, have been painted in oils on canvas rather than buon fresco.

Frescos aren’t the only way of making very large and monumental paintings for places like churches, though. The walls of Venetian buildings are particularly unsuitable for secco or fresco, because they remain so damp all year round. Hence the painters of Venice were innovators in constructing very large canvases, and you will find few frescos there as a result.

The introduction of Mac OS X in 2000-01 brought conventional text-based logging to the Mac, with standard logs including system.log and console.log.

With the release of macOS 10.12 Sierra in 2016, those were almost completely replaced by the Unified Log, which has continued evolving since. Intended to provide a single efficient logging mechanism for user and kernel modes, its design goals are:

• to maximise information collection with minimum observer effect;
• as much logging on as much of the time as possible;
• compression of log data for efficient use of space;
• a managed log message lifecycle;
• designed-in privacy protection;
• to be common across all Apple’s operating systems;
• all legacy APIs (NSLog, asl_log_message, syslog, etc.) to be redirected into the single log;
• to support debugging, but not system administration or audit.

To achieve this, log entries are written using the OSLog API (or Logger from Swift), handled by the logd daemon and compressed into a buffer. From there entries are either retained in memory if intended to be ephemeral, or written out to a file. Log entries are only made from the start of kernel boot; earlier phases of the boot process instead save breadcrumbs that are largely inaccessible and unintelligible.

Performance of writing log entries is excellent, with a single process able to write sequential entries every 400 ns from a code loop, a rate of 2.5 million entries per second, although that rate is unlikely to be sustainable for long.

Log storage

There are two main groups of files that store log entries: those kept in /var/db/diagnostics/Persist/ in the form of tracev3 files containing regular log entries, and further tracev3 files in /var/db/diagnostics/Special/ containing additional shorter-life entries. Additional and lengthier log data can instead be stored in files named by UUID in /var/db/uuidtext/, and there’s also support for special Signpost entries intended for performance measurement, and scope for high-volume collection.

tracev3 files use a proprietary compressed binary format that remains undocumented to this day, but has been largely reversed. Apple’s APIs don’t give direct access to their contents, only through closed-source utilities such as the log command tool and programmatically through the OSLog API. Where users want a more portable format, Apple recommends conversion to a logarchive package, although that’s also undocumented and only directly accessible using log, the Console app and some third-party utilities. Logarchives still store all log entries in tracev3 files.

Collection and retention of entries from different subsystems is configured in logging profiles, XML property lists stored in /System/Library/Preferences/Logging (read-only, in the System volume) and /Library/Preferences/Logging, which the user controls. You can create your own custom profiles, or modify them on the fly using the log command.

The logd service maintains tracev3 files and their ancillaries, weeding them to remove time-expired entries. It does so to constrain the total size of log files in the system, rather than rolling them to retain all entries for a specified period. Most ephemeral entries are weeded within 5 minutes of being written to the log, leaving persistent entries to remain for the following days, depending on the volume of new entries being written. For example, in a 3 second period of collection, when all entries were obtained within a minute of being written, 22,783 entries were found. Five minutes after they had been written, only 82% of those remained, and over 8 hours later that had fallen to 80%, or 18,309.

Log content

In contrast to traditional text-based logs, entries in the macOS log contain structured data in set fields, such as the datestamp, subsystem and log message. The number of fields available from the log command has risen from 16 to over 25, but entries are constrained in which fields are available, according to their type. Currently there are four types, Regular, Activity, Boundary and Signpost.

Some log entries, notably those written to /var/db/uuidtext/, can have very long message fields, extending to dozens of lines. Among the most verbose is the com.apple.runningboard subsystem, which not infrequently writes the whole of its records for an app into the message field of a single log entry.

Privacy

Privacy protection censors content of log entries when they’re written, replacing sections of the message field with <private> in accordance with the formatting string for that message. This protection can be disabled, but as entries are censored when they’re written, that only affects those written after censorship has been removed, and can’t be applied retrospectively.

One significant change in macOS 26 Tahoe is that the message contents of all log entries written using the old NSLog interface are replaced with <private>, rendering them essentially useless. Since macOS 10.12.4, all access to log entries has required admin privileges.

Access

macOS provides users with two means of accessing entries in the log: the log command tool, and Console app. In common use, log generates text output, so losing the original data fields, one of the major advantages of the Unified Log. Console offers two methods of access: a live stream of entries, or browsing past entries in a saved logarchive.

I have four main tools that provide extensive log access:

• LogUI, using the OSLog API and displaying entries as formatted SwiftUI Lists;
• Mints, offering special-purpose browsers for Time Machine, APFS, and other domains;
• Ulbow, using the log tool and displaying entries as formatted Rich Text using AppKit;
• Consolation, using the log tool and displaying entries as formatted Rich Text using AppKit.

These are available from their product page, and here for Mints.

From their tragic encounter with tormented souls in the Suicide Wood, Virgil leads Dante onto a barren and sandy plain, where groups of spirits are in different postures, naked under steady showers of flakes of fire. These fall on their flesh, and set the sand afire underneath them. They are being punished for their differing acts of violence against God: blasphemers lie flat on their backs, sodomites are moving at all times, and usurers crouch with purses strung from their necks.

The two talk with Capaneus, a huge man who was once a powerful king and waged war against the city of Thebes, and a blasphemer who was struck by a thunderbolt for his arrogance towards the (classical and pagan) gods.

Among the sodomites is the prominent Guelph encyclopaedist Brunetto Latini (c 1220-94), who may well have been Dante’s mentor at one time. Also identified are Priscian a Latin grammarian, Francesco d’Accorso a legal scholar, and Andrea de’ Mozzi a bishop of Florence, together with three other Florentines.

Virgil explains some more of the topography of Hell, how waters originating from a statue on Mount Idaeus (Ida) on the island of Crete flow down to form its three principal rivers, the Acheron, Styx and Phlegethon. The statue of the Old Man of Crete has a gold head, silver arms, brass torso, and iron below, apart from a terracotta foot. This follows the mythical ‘ages of mankind’ in descent, and its tears feed the waters of Hell.

Dante is next led down towards a vile monster with the face of an honest man but the body of a serpent, its body seemingly tattooed with knots and whorls, and a sting at the end of its great tail: this is Geryon, in classical myth a cruel king who was killed by Hercules, and here forming an image of fraud.

Before reaching that monster, the pair see some usurers on the ground. They are identified as contemporary members of prominent Florentine and Paduan families known for their riches and usury.

Virgil then jumps onto Geryon’s back, and encourages Dante to have courage to join him there. Once they have both boarded, Virgil tells Geryon to fly off, and the monster carries them down through a hundred spiralling turns to the foot of a high cliff.

Virgil and Dante have now descended to circle eight.

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.

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 in current use. They were followed in 1867 by more illustrations for Purgatorio and Paradiso. This article looks at his paintings.

John Flaxman (1755–1826) was a British sculptor and draughtsman who occasionally painted too. When he was in Rome between 1787-91, he produced drawings for book illustrations, including a set of 111 for an edition of The Divine Comedy. In 1810, he was appointed the Professor of Sculpture to the Royal Academy in London, and in 1817 made drawings to illustrate Hesiod, which were engraved by William Blake.

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.

Bartolomeo Pinelli (1781-1835) was a Roman illustrator and engraver who provided illustrations for a great many books, and specialised in the city of Rome. He made 145 prints to illustrate Dante’s Divine Comedy, most probably in the early nineteenth century.

Francesco Scaramuzza (1803–1886) was an Italian painter who specialised in mythological and historical narratives. He became obsessed with Dante’s Divine Comedy, and for much of his career worked on producing paintings and drawings of its scenes. He worked mainly in Parma, in Italy.

Bertel Thorvaldsen (1770–1844) was the greatest Danish sculptor, and one of the foremost in Europe. He worked most of his life in Italy, although the Thorvaldsens Museum with much of his work is in the city of Copenhagen, in a place of honour by the Christiansborg Palace. From humble origins, he trained at the Royal Danish Academy of Art, where he was extremely successful. He arrived in Rome in 1797, and remained there until 1838, when he was welcomed as a returning hero in Copenhagen.

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 326. Here are my solutions to them.

1: Melody containing cocoa plugs the ears.

2: Confident bearing of attached label to track your stuff.

3: Breeze reduction moves files wirelessly.

The common factor

I look forward to your putting alternative cases.

This article lists the firmware versions of Macs that have been successfully upgraded to run macOS 26.0 Tahoe.

Apple doesn’t provide an official list of the current firmware versions which should be installed on each model of Mac. Intel models with T2 chips consist of two parts, the second covering iBridge in the T2. Apple silicon Macs just give an iBoot version.

Macs still running older versions of macOS are covered by information at:

• this page for Sequoia,
• this page for Sonoma,
• this page for Ventura,
• this page for Monterey,
• this page for Big Sur,
• this page Catalina,
• this page for High Sierra,
• this page for El Capitan and earlier.

Apple silicon Macs

The current iBoot version is 13822.1.2.

Intel Macs with T2 chips

The current EFI version is 2092.0.0.0.0 and iBridge is 23.16.10350.0.0,0.

Apple Studio Display

The current version remains 17.0 (build 21A329).

How to check your Mac’s firmware version

The simplest way is to run my free tool SilentKnight, available from its product page.

Alternatively, use the About This Mac command at the top of the Apple menu; hold the Option key and click on the System Information command. In the Hardware Overview listing, this is given as the Boot ROM Version or System Firmware Version.

What to do if your Mac’s firmware is different from that shown

If the version is higher than that given here, it indicates that Mac has installed a more recent version of macOS, which has installed a later version of the firmware. This is almost invariably the result of installing a beta-release of the next version of macOS. This occurs even when the newer macOS is installed to an external disk.

If the installed version of firmware has a version lower than that shown, you can try installing macOS again to see if that updates the firmware correctly. If it still fails to update, you should contact Apple Support.

Firmware updaters are now only distributed as part of macOS updates and upgrades: Apple doesn’t provide them separately.

All T2 and Apple silicon models automatically check the integrity of their firmware in the early part of the boot process anyway. If any errors are found then, the Mac should be put into DFU mode and firmware restored from the current IPSW image file. In Sonoma and later this can be performed in the Finder, and no longer requires Apple Configurator 2. Full instructions are provided in this article. If you don’t have a second Mac or don’t feel that you can perform this yourself, it should be easy to arrange with an Apple store or authorised service provider.

(Last updated 19 September 2025)

In 1868, Frédéric Bazille completed two of his most successful figurative paintings, The Family Gathering, started the previous summer, and View of the Village.

Another painting of figures in a landscape he made that summer is Fisherman with a Net (1868), which the following year was refused by the Salon jury. This was painted on the banks of the River Lez, close to Bazille’s family’s estate at Méric. Unlike most of his other figures in a landscape, it was executed relatively quickly with a single preparatory drawing.

The stark contrast between the flesh figures and the rich greens of the surrounding vegetation makes the two men pop out almost incongruously.

Bazille remained productive through the following winter, in part because he and Renoir reorganised their shared studio. His portrait of Pierre Auguste Renoir (1868-69) was a quick oil sketch that probably filled in some free time when waiting for models to become available. It was painted over an abandoned still life, and is a wonderfully painterly snapshot in oils.

His growing success ensured that he had no difficulty finding models. Woman in Moorish Costume was painted during the winter of 1868-69, and is a nod towards the vogue of ‘orientalism’ at the time.

He also painted his second portrait of Edmond Maître in early 1869. He had met Maître (1840-1898) in 1865. Like Bazille, he had moved to Paris to study, in his case law in 1859, but had become a civil servant to allow him sufficient free time to enjoy his pursuits, including music and art. They were to remain close friends until Bazille’s death.

He was visited by Daubigny, and Alfred Stevens invited him to his evening meetings. With continuing hostility from some members of the Salon jury, notably Jean-Léon Gérôme, Bazille had only one painting, View of the Village, accepted for the Salon of 1869. However, he wasn’t discouraged, and seems to have relished the ongoing battle between the Impressionists and Gérôme.

Bazille started painting Summer Scene, also known as Bathers, during the summer of 1869 when he was on holiday in Montpellier. He had already made a series of compositional studies starting in February that year, but when he was working on the canvas, he found it hard going, and complained of headaches and other pains.

He eventually opted for a composition based on strong diagonals, in which the bathers in the foreground are in shade, while the two wrestlers in the distance are lit by sunshine. The landscape background was painted from the hot green mixture of grass with birch and pine trees, typical of the banks of the River Lez near Montpellier. He completed this in early 1870, and it was accepted for the Salon of that year, where it was well-received by the critics.

La Toilette (1870) was one of his three planned projects for the winter of 1869-70. However, with three models required, he had to ask his father for money to cover their cost. This was refused by the Salon jury of 1870, when Daubigny resigned from the jury in protest.

Bazille’s Studio, or The Studio on the Rue La Condamine, was another project he worked on during that winter.

Bazille clearly liked painting his studio, but the three canvases he completed showing his different studios aren’t as simple as they might appear. Inspired by Fantin-Latour’s A Studio in the Batignolles Quarter (1869-70), which includes Bazille, it is in some ways its antithesis.

Bazille was careful in the choice of paintings shown, which include View of the Village on the easel, Fisherman with a Net, Terrace at Méric, and La Toilette as yet unfinished. The largest painting hanging is Renoir’s Landscape with Two Figures, and there is also a small still life by Monet. Bazille used these as pictures within a picture to map his career, from the past to his aspirations for the Salon in 1870, not in his successes so much as in the paintings refused, and better appreciated by the colleagues shown.

Flowers (c 1870) is one of a small group of floral paintings made during the Spring of 1870, when he moved to his own studio in the rue des Beaux-Arts.

Bazille painted two related but different versions of La négresse aux pivoines (Young Woman with Peonies) in the Spring of 1870. His professional model is the same as that used for La Toilette. She is normally read as being a servant engaged in making the floral arrangement, although in the other version (at the National Gallery of Art in Washington) she appears to be a flower seller.

At the time, the dominant flower, the peony, was a relatively recent import to France, and would probably have been seen as bringing a touch of exoticism to the two paintings. The striking vase may have been borrowed from Fantin-Latour. Rishel has proposed that this painting in Montpellier was intended as homage to Gustave Courbet, and that in Washington to Eugène Delacroix.

In the summer of 1870, Bazille worked on three paintings when he was staying alone at Méric. Study for a Young Male Nude appears odd because it was painted over an unfinished painting of two women in a garden, and the lower third of the canvas shows the lower part of their dresses.

On 19 July 1870, France declared war on Prussia. Within a month, Bazille had enlisted in the Third Zouave Regiment. He spent September training in Algeria, then returned into combat in France. On 28 November 1870, Bazille was killed at the Battle of Beaune-la-Rolande. He would have celebrated his twenty-ninth birthday just over a week later.

In but eight years of painting, Bazille had shown great technical skill, originality, and high promise for his future in the Impressionist movement. Unlike his close friends Monet and Renoir, he was particularly interested in and adept at depicting figures in landscapes. That brilliant future, which would surely have changed Impressionism too, was abruptly ended in a futile attempt to relieve the Siege of Paris.

References

Wikipedia.

Hilaire, Michel, & Perrin, Paul (eds) (2016), Frédéric Bazille and the Birth of Impressionism, Flammarion. ISBN 978 2 080 20285 7.

It has been barely a year since XProtect changed from stalwart to bogeyman. Over the course of dozens of updates through to macOS Sonoma, if there was one security data update you could rely on, it was XProtectPlistConfigData containing the many rules for XProtect. They guarded us through the dangerous days of Flash Player, the perils of ransomware, and a succession of stealers.

Then in Sequoia that changed, and XProtect’s data became stored in two locations, each with its own update method. The traditional location in CoreServices continued to be updated through softwareupdated, while the copy in the new location in /var/protected/xprotect has been updated by XProtectUpdateService over a connection to iCloud.

With both locations in play, XProtect updates have become more complicated. Some updates only came for one location, such as versions 5273 and 5275 that were released only to Sequoia’s new location. To help us manage XProtect in its new location, Apple provided a command tool, xprotect. That can check which version is available via iCloud, and update that when the local copy was no longer the latest.

One valuable feature was that it could also use a copy in the traditional location to update the new location, in the event that version was more recent than that available from iCloud, but most recently that has been disabled. Now, if a Mac running Sequoia or Tahoe has successfully updated its traditional location but not the copy in the new location, the user is unable to do anything to rectify that, and has to wait until that update is made available from iCloud. Sometimes both are provided at the same time, but it’s also common for iCloud to lag the traditional version by an hour or more, sometimes even longer.

Last week, with the update to XProtect 5315, the day after many of us were preoccupied with macOS updates, something even stranger happened. At around 18:00 GMT on 16 September, softwareupdated became able to download and install that new version into its traditional location, enabling macOS versions up to Sonoma to update successfully. But no such update was made available via iCloud for Sequoia or newly upgraded Tahoe systems, not for another 24 hours. Over that period attempts to obtain or convert the update using xprotect update were unsuccessful.

However, some hours after the traditional update was installed by those who had upgraded to Tahoe, XProtect’s new location was silently updated to 5315. Its version number had gone bump in the night. But if the xprotect command tool couldn’t accomplish that for the user, how could macOS? Were these silent updates coming by telepathy or radio waves?

Although there was no record in any of the usual places, such as Installations in System Information, or even found by my app SystHist, the xprotect version command disclosed that my Mac mini had updated XProtect’s new location at 06:46 GMT on the morning of 17 September, enabling me to hunt that event down in the log.

That update had been accomplished by a background check scheduled and dispatched by DAS-CTS (I have corrected times here to GMT):
2025-09-17 06:46:42.615072 com.apple.duetactivityscheduler REQUESTING START: 0:com.apple.security.syspolicy.xprotect-update:7874AD

This in turn fired up XProtectUpdateService
2025-09-17 06:46:42.695517 com.apple.xprotect Connecting to XProtectUpdateService
2025-09-17 06:46:42.744182 com.apple.security.XProtectFramework.XProtectUpdateService XProtectUpdateService booting
2025-09-17 06:46:43.157255 com.apple.security.XProtectFramework.XProtectUpdateService Attempting to apply update: [private]
2025-09-17 06:46:43.191178 com.apple.security.XProtectFramework.XProtectUpdateService Update completed. Activated update [private]

So the XProtect update had been completed and activated at 06:46 that morning. But how, given that iCloud was still only offering the old version?
2025-09-17 06:46:43.193159 com.apple.syspolicy.activities Finished Xprotect update in 496.4100122451782 ms: Error Domain=XProtectUpdateError Code=2 "Activated update LocalUpdate[5315]" UserInfo={NSLocalizedDescription=Activated update LocalUpdate[5315]}
2025-09-17 06:46:43.193285 com.apple.syspolicy Sent CloudTelemetry event: Xprotectupdateresult

“Activated update LocalUpdate” can only mean one thing, that XProtectUpdateService did what xprotect update used to do, and used the copy of XProtect 5315 in the traditional location to update the new location, taking just under half a second. In addition, com.apple.syspolicy had sent news of that event to Apple via iCloud.

That didn’t work for my old iMac Pro, still running Sequoia, though, which had to wait for the iCloud version of XProtect data to be updated, and wasn’t using version 5315 until 20:17 GMT on 17 September, over 26 hours after its initial release.

Prior to Sequoia, all supported and many unsupported versions of macOS got the same XProtect updates, available immediately they were released through Apple’s software update servers. Just over a year later,

• Macs running Sonoma and unsupported versions of macOS could be updated as soon as the softwareupdated update became available, in the traditional way;
• Macs running Sequoia could only be updated 24 hours later, when the iCloud update was made available;
• Macs running Tahoe could have been updated at any time after the traditional update had been installed, until the update was finally made available through iCloud.

I’m so looking forward to the time when I don’t need to use SilentKnight, the xprotect command and my log browser LogUI to track XProtect updates, and when those become timely again.

Impressionist painting is today known overwhelmingly from the many landscapes painted by Claude Monet and Camille Pissarro. The figurative paintings of Auguste Renoir are often thought of as more of a commercial undertaking, those of Edgar Degas are seen as exceptions, and Paul Cézanne’s are usually glossed over altogether.

One of the reasons that Impressionist figurative painting is now largely ignored is that its greatest exponent was killed in 1870, just as he was reaching his peak. When Frédéric Bazille was shot dead by Prussian soldiers during the Franco-Prussian War, that changed the course of Impressionism. This weekend I show some of the paintings from the seven short years of his career as an oil painter before his sudden death.

Jean Frédéric Bazille was born into an affluent family in Montpellier, France, a city on the Mediterranean coast with one of the oldest universities in the world. He was inspired to paint when he saw some of Delacroix’s works, but his family wanted him to study medicine. An accommodation was reached, and in 1859, he started his medical studies at Montpellier University.

In November 1862, Bazille left his home city to transfer to medical studies in Paris. A friend introduced him to Charles Gleyre’s studio, and some time in early 1863, he seems to have started as a pupil there, while continuing his medical training. He met Claude Monet there in March or April of that year, and started painting en plein air with him, probably with Sisley and Renoir too. By the end of 1863, he seems to have been making good progress with Gleyre, although his parents were keen to remind him of the precedence of his medical studies.

In January 1864, he started renting his first studio, and that summer travelled to Normandy with Monet. Shortly after that, he failed his medical exams, and dropped out from those studies, leaving him painting full-time.

In the late summer of 1864, in an effort to convince his family that he was serious about his career in art, Bazille started work on his La Robe Rose (The Pink Dress). Using his cousin Thérèse des Hours, aged fourteen, as his model, he painted this from a drawing he made at Méric, looking towards the village of Castelnau-le-Lez, near Montpellier.

In his drawing, the model is looking to the right and out of the picture plane, with her head rotated by about ninety degrees from that shown in this painting. As this was his first painting of a figure set in a landscape, Bazille seems to have wanted to avoid tackling her face, and opted for her looking away from the viewer.

This painting wasn’t seen by the public until 1910, but since then has become accepted as one of his major works, which is surprising for such a challenging motif and such a relative novice.

In the autumn of 1864, when he returned to Paris, Bazille didn’t go back to Gleyre’s studio, but painted mostly from the models in Monet’s studio. In January 1865, the two painters moved into a new studio together, above Delacroix’s former flat in rue de Furstenberg.

It’s not clear exactly when he painted his Self-Portrait with Palette, but it was most probably in 1865. It’s a remarkably accomplished work, given the complexity of arranging the mirror and canvas to result in this unusual pose.

In May 1865, Bazille left the city for the Forest of Fontainebleau, where the Barbizon School had been centred. There he painted Landscape at Chailly in company with Monet, and possibly Renoir and Sisley. Although clearly influenced by that style, Bazille’s colours are much brighter, and escape the sombre browns and greens that dominated Barbizon paintings.

In May of the previous year, Bazille and Monet had travelled to the Channel coast, to Le Havre. This was Monet’s home ground, but the first time that Bazille had explored this coast. Oddly, Bazille painted The Beach at Sainte-Adresse a year later, in May 1865, as one of a pair of paintings for an uncle. It appears to have been partially copied from a painting of the same name by Monet, made when the two had visited Sainte-Adresse the year before. Bazille re-arranged the yachts and changed the staffage of the beach, but the sea, sky, and coastline are essentially the same.

During the summer of 1865, Bazille painted Monet lying in bed, injured, at the Lion d’Or Inn, in The Improvised Field Hospital (1865); sadly I have been unable to find a good image of that painting.

In the late autumn, Gustave Courbet visited Monet and Bazille, and congratulated them on their work. However, in January 1866, Bazille left their shared studio to set up in his own at last. In the Spring, he submitted two paintings to the Salon, of which one, Still Life with a Fish, was accepted. For a while during the winter of 1866-67, Monet lodged in Bazille’s studio.

During this period, he started to paint The Little Gardener (1865-67), but seems to have abandoned it with the foreground incomplete. It was another step in his development of figures in landscapes, and a precursor to his paintings of 1868.

Bazille first wanted to paint at Aigues-Mortes, east of Montpellier, in the summer of 1866, but didn’t get there until May 1867. He then produced one of his most painterly and brilliant landscapes of The Western Ramparts at Aigues-Mortes, as well as several other views, including many sketches.

I include this Portrait of Paul Verlaine (1867) because of its controversial history. On the strength of the signature on it (which isn’t legible in this image), it had been attributed to Gustave Courbet, but most recently has been claimed to have been painted by Bazille. If that’s accurate, its painterly style is surprising and impressive.

In the Spring of 1867, Bazille submitted two more paintings for the Salon, but both were refused. He drafted a petition calling for a new Salon des Refusés, which was signed by Daubigny, a distinguished member of the Salon jury at the time.

During the summer of 1867, Bazille started work on Portraits of the *** Family also known as The Family Gathering, which he didn’t complete until January the following year. This seems to have been one of his most carefully composed paintings, and he devoted a series of sketches to getting the arrangement of the figures and the terrace just right.

The figures include the artist, squeezed in last at the extreme left, an uncle, Bazille’s parents seated on the bench, Bazille’s cousin Pauline des Hours and her husband standing, an aunt and Thérèse des Hours (model for The Pink Dress) seated at the table, his brother Marc and his partner, and at the right Camille, the youngest of the des Hours sisters. This painting marked a special version of a regular summer meeting, as Pauline des Hours and Bazille’s brother Marc married the partners shown in the late summer of 1867.

At the time, such group portraits were exceptional in French art, although they were popular in Britain, and had been so in the past in the Netherlands, of course. It’s perhaps unsurprising that it was exhibited at the Salon in 1868, and remains one of Bazille’s finest and most innovative works.

In January 1868, Bazille moved into a new studio with Renoir, at what was renamed the following year rue La Condamine, in the Batignolles. He was a regular attender at the Café Guerbois with Manet, Degas, Duranty, Zola, Astruc, and Cézanne.

Bazille painted another of his best-known works, View of the Village, during the summer of 1868. He based this on sketches made in the Spring at Saint-Sauveur, of a farmer’s daughter in her Sunday-best dress, in Bel-Air Wood, overlooking the River Lez, near Montpellier. Its location and composition are variations of the theme he first developed in The Pink Dress, and he was also reminded of his model for that painting, his cousin Thérèse des Hours.

He probably completed this in the autumn and early winter of 1868, and the following year it was exhibited at the Salon. Puvis de Chavannes and several of the critics were full of praise for it, and for Bazille. He also made an etching of it, the only print made from one of Bazille’s paintings during his lifetime. It remains his greatest success.

References

Wikipedia.

Hilaire, Michel, & Perrin, Paul (eds) (2016), Frédéric Bazille and the Birth of Impressionism, Flammarion. ISBN 978 2 080 20285 7.

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

1: Melody containing cocoa plugs the ears.

2: Confident bearing of attached label to track your stuff.

3: Breeze reduction moves files wirelessly.

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.

The original 128K Mac from 1984 came with a single Motorola 68000 processor running at 8 MHz that could only run one app at a time. Yet today’s Macs come with multiple CPU cores that can comfortably run several substantial apps simultaneously, while running a Time Machine backup and other tasks in the background. This brief history outlines the journey between them.

A processor with a single core and no support for multi-tasking runs one sequence of instructions at a time. When those call for an operating system function to be performed, the running app is interrupted to hand control over to the system, and once that has completed, control is passed back to the app. That’s what the first Macs did until Andy Hertzfeld wrote Switcher, released by Apple in April 1985. This allowed the user to switch between running more than one app, but was still limited to running just one of them at a time.

Multitasking

Over the next couple of years, some third-party utilities were produced to go further than Switcher, but it wasn’t until 1987 that MultiFinder replaced Switcher, and was integrated into System 7 in 1991. Developed by Erich Ringewald and Phil Goldman, this brought cooperative multitasking, which was to become the mainstay of classic Mac OS.

In computers with a single processor core, multitasking is a way of cheating to give the impression that the processor is doing several things at once, when in fact all it’s doing is switching rapidly between two or more different programs. There are two fundamental models for doing that:

• cooperative multitasking, in which individual tasks yield to give others processing time;
• preemptive multitasking, in which a scheduler switches between tasks at regular intervals.

When a processor switches from one task to the next, the current task state must be saved so it can be resumed later. Once that’s complete, the next task is loaded to complete the context switch. That incurs overhead, both in terms of processing and in memory storage, which are less when switching between lightweight tasks. Different strategies have been adopted to determine the optimum size of tasks and overhead imposed by context switching, and terminology differs between them, variously using words such as processes, threads and even fibres, which can prove thoroughly confusing.

Classic Mac OS thus has a Process Manager that launches apps in cooperative multitasking. This works well much of the time, but lets badly behaved tasks hog the processor and block other tasks from getting their fair share. It’s greatly aided by the main event loop at the heart of Mac apps that waits for control input to direct the app to perform work for the user. But when an app charges off to spend many seconds tackling a demanding task without polling its main event loop, that app could lock the user out for what seems like an age.

In February 1988 Apple released the first Unix for Macintosh, A/UX, which came with preemptive multitasking. That was added to Mac OS in 1996 in System 7.5.3, in Multiprocessing Services, and further enhanced in Mac OS 8.6 three years later. Cooperative multitasking was also supported by the Thread Manager.

Threads

In 2000 Apple’s hardware and software changed radically. Its first Macs with dual processors (apart from the Power Mac 9600/200MP that was available briefly in 1997) came in PowerPC 7400 (G4) chips in Power Mac G4 desktop systems, and Mac OS X brought several types of thread that could be used to manage processing on multiple processors or CPU cores, together with preemptive multitasking. Thread types include low-level Mach threads, higher-level POSIX threads or Pthreads that replaced Multiprocessing Services, Java Threads, Cocoa’s NSThreads, and cooperatively scheduled threads using the Carbon Thread Manager. The following diagram summarises Apple’s current terminology.

In most cases, we’re considering applications with a GUI, normally run from a bundle structure. These can in turn run their own code, such as privileged helper apps used to perform work that requires elevated privileges. In recent years, there has been a proliferation of additional executable code associated with many apps.

When that app is run, there’s a single runtime instance created from its single executable code, and given its own virtual memory and access to system resources that it needs. This is a process, and listed as such in Activity Monitor, for example.

Each process has a main thread, a single flow of code execution, and may create additional threads, perhaps to run in the background. Threads don’t get their own virtual memory, but share that allocated to the process, although they have their own stack. On Apple silicon Macs they’re easy to tell apart as they can only run on a single core, although they may be moved between cores, sometimes rapidly.

Within each thread are individual tasks, each a quantity of work to be performed. These can be brief sections of code and are more interdependent than threads. They’re often divided into synchronous and asynchronous tasks, depending on whether they need to be run as part of a strict sequence.

In 2005 the Power Mac G5 was the first Mac to use dual-core PowerPC G5 processors, then the iMac 17-inch of the following year used Apple’s first Intel Core Duo processor with two cores.

Grand Central Dispatch

In 2009 Mac OS X 10.6 Snow Leopard introduced a new dispatcher, named Grand Central Dispatch (GCD) after Grand Central Terminal in New York City, and that was enhanced in macOS Sierra a decade later. More recently it has been referred to simply as Dispatch.

At its heart, GCD is a dispatcher managing queues of tasks, activating those that need most to be run, and leaving the less pressing to wait a bit longer. It has its own queues, as well as those assembled by apps. Some are run as simple queues with a first in first out rule, others using sophisticated heuristics to determine relative priorities. There’s a detailed account of GCD internals in Jonathan Levin’s book *OS Internals volume 1, and Apple’s current developer documentation is here.

GCD was introduced for Macs with multiple identical cores, to support their symmetric multiprocessing (SMP), and with the release of the first Apple silicon Macs in November 2020 it has managed queues of threads to be dispatched for execution on two CPU core types, Performance and Efficiency. Core allocation is now managed according to the Quality of Service (QoS) assigned to each thread. When used on SMP processors with no contention for core availability, QoS has limited effects on thread performance, but performance on P and E cores may differ by a factor of 10.

Over the last 41 years, macOS has gained thorough support for getting the best performance from multiple tasks, threads, and processes in chips that contain up to 32 CPU cores of two types – a far cry from that single 68000 processor.

The humble domestic chicken is probably the most common and widely distributed farm animal. It originated in about 8,000 BCE in south-east Asia and spread its way steadily across every continent except Antarctica. It probably reached Europe before the Roman Empire, and since then has been commonplace. Perhaps because of its small size and frequent presence, it features in relatively few paintings.

The cruel sport of cockfighting accompanied its spread, and is depicted in Jean-Léon Gérôme’s first successful painting in 1846.

This motif had started from a relief showing two adolescent boys facing off against one another. Gérôme felt he needed to improve his figurative painting, and after Delaroche’s advice decided to develop that image by replacing one of the boys with a girl. In both Greek and English (but not French) the word cock is used for both the male genitals and a male chicken, and the youthful Gérôme must have found this combined visual and verbal pun witty and very Neo-Greek.

There’s a curious ambivalence in its reading too: two cocks are fighting in front of the young couple. Is one of the birds owned by the girl, and if so, is it the dark one on the left, which appears to be getting the better of the bird being held by the boy? Either way, it’s a lightly entertaining reflection on courtship and gender roles, and a promising debut. The Cock Fight earned Gérôme a third-class medal, and he sold the painting for a thousand francs. With the benefit of favourable reviews from critics, the following year brought him lucrative commissions, and a growing reputation.

A dead chicken plays a significant role in one of Rembrandt’s most famous group portraits.

His vast group portrait of The Night Watch (1642) is the most famous of all those of militia in the Dutch Republic. It features the commander and seventeen members of his civic guard company in Amsterdam. Captain Frans Banninck Cocq (in black with a red sash), followed by his lieutenant Willem van Ruytenburch (in yellow with a white sash) are leading out this militia company, their colours borne by the ensign Jan Visscher Cornelissen. The small girl to the left of them is carrying a dead chicken, a curious symbol of arquebusiers, the type of weapon several are carrying.

For a young child, cockerels can appear large and threatening, as used by Gaetano Chierici in a delightful visual joke.

His undated painting of A Scary State of Affairs calls on our experience of the behaviour of cockerels and geese. An infant has been left with a bowl on their lap, and their room is invaded first by cockerels, then by those even larger and more aggressive geese. The child’s eyes are wide open, their mouth at full stretch in a scream, their arms raised, and their legs are trying to fend the birds away.

Being among the most humble and everyday domestic species, chickens seldom make the limelight in religious narratives.

Murillo’s Adoration of the Shepherds from about 1650 is an exception featuring unusual additional details including the old woman carrying a basketful of eggs, and chickens in front of the kneeling shepherd.

In most paintings including chickens, though, they are just extras in the farmyard.

Paulus Potter’s Figures with Horses by a Stable (1647) includes finely painted horses, chickens, a dog, and distant cattle, with a magnificent tree in the centre and a sky containing several birds.

In Chickenfeed from 1867, Hans Thoma tackles this genre scene in a traditional and detailed realist style.

Alberto Pasini’s Market Scene from 1884 has an eclectic mixture of produce, ranging from live chickens to pots and the artist’s signature melons.

Évariste Carpentier’s undated Eating in the Farmyard, an example of the rural deprivation which sparked Naturalist art, shows two kids surrounded by animals and birds in this much-used space.

Here, Carpentier’s old woman is busy Feeding the Chickens.

Friedrich Eckenfelder’s Zollernschloss, Balingen from about 1884-5 shows a small yard just below the back of this castellated farm in Germany, with its lively flock of chickens.

Gustav Klimt had probably painted his first small landscapes between 1881-87, and returned to the genre more seriously in about 1896. This work, variously known as After the Rain, Garden with Chickens in St. Agatha, or similar, is thought to have been painted when Klimt stayed in the Goiserer Valley with the Flöge family in the summer of 1898.

Very occasionally, a chicken may come as something of a surprise.

Hieronymus Bosch’s Ship of Fools, a fragment from a larger Wayfarer triptych painted in 1500-10, is actually a small boat, into which six men and two women are packed tight. Its mast is unrealistically high, bears no sail, and has a large branch lashed to the top of it, in which is Bosch’s signature owl. Its occupants are engaged in drinking, eating what appear to be cherries from a small rectangular tabletop, and singing to the accompaniment of a lute being played by one of the women. A man has climbed a tree on the bank to try to cut down the carcass of a chicken from high up the mast.

Each of the main security services in macOS such as XProtect relies on data commonly stored in separate files on the Data volume so they can be updated directly outside full macOS system updates. Those are released silently by Apple, unannounced, and you aren’t even sent a notification when they’ve been updated.

Currently, those most frequently updated are XProtect and XProtect Remediator, the former being updated most weeks. However, Sequoia changed the way that XProtect’s data is updated, and it’s now intended to occur over a connection to iCloud rather than through Software Update, while XProtect Remediator continues to rely on the latter rather than iCloud.

This article details each of the main security data files found in macOS 26 Tahoe, together with others involved in related system functions. Several other bundles that formerly had roles in security have now been emptied, left frozen in time, or removed completely. As Apple doesn’t document any of them beyond mentioning their existence and simplified role, the information given is the best that I can find currently.

Main Security Data

XProtectPayloads, alias XProtect.app and XProtect Remediator
This contains a suite of specialised malware detection and remediation tools, in the app bundle XProtect.app in the Data volume at /Library/Apple/System/Library/CoreServices. This was introduced in macOS 12.3, then version 62 was pushed to Catalina and later on 17 June 2022. Executables include a replacement for MRT, and many scanners for specific malware types. My free XProCheck inspects its reports for malware detection and remediation. This is normally updated every month or so using Software Update or a substitute.

XProtectPlistConfigData
These are whitelists and blacklists used by XProtect. Since Sequoia, two different locations are used: the primary is at /var/protected/xprotect/XProtect.bundle in the Data volume; the secondary is also in the Data volume at the traditional location of /Library/Apple/System/Library/CoreServices/XProtect.bundle, and can used as a fallback when there’s no bundle at the primary location. While previous versions of macOS still obtain updates through Software Update, Tahoe is also intended to update the primary bundle via a CloudKit connection to iCloud. This is routinely updated every week, at the same time as updates for previous versions of macOS. You can force an update using the command sudo xprotect update in Terminal, if a more recent version is available.

Bastion
These provide rules and exceptions for XProtect Behaviour Service (XBS). First introduced in Ventura, this service monitors for and logs processes that access sensitive locations such as folders containing browser data. This doesn’t block behaviours, only records them in its database at /var/protected/xprotect/XPdb, and reports them to Apple as security intelligence. Bastion rules are defined in bastion.sb and BastionMeta.plist inside /Library/Apple/System/Library/CoreServices/XProtect.app Those are updated irregularly.

AppleKextExcludeList
Latest version: 21.0.0, 9 September 2025 (26.0 release).
This is a huge list of kernel extensions that are to be treated as exceptions to Tahoe’s security rules, and is stored in the Data volume in /Library/Apple/System/Library/Extensions/AppleKextExcludeList.kext, at Contents/Resources/ExceptionLists.plist. At one time, this was a blacklist of kexts to block, but in Mojave 10.14.5 that changed, and it has since been a list of over 18,000 kexts that are given exceptional treatment, as explained here. However, this doesn’t appear to apply to Apple silicon Macs, as they have their own separate rules about which kexts to allow and which to block, that are far more stringent. Accordingly, this list should go away in macOS 27.

Others

IncompatibleAppsList
Latest version: 260.200 (26.0 release).
This is a bundle in the Data volume at /Library/Apple/Library/Bundles/IncompatibleAppsList.bundle which contains IncompatibleAppsList.plist, listing many known incompatible versions of third-party products, including Flash Player.

Vestigial Data

MRTConfigData
Last version: 1.93, 14 July 2022.
This was Apple’s Malware Removal Tool stored in the Data volume at Library/Apple/System/Library/CoreServices/MRT.app, so that it could remove any malware which macOS detected. This has now been replaced by the XProtectRemediatorMRTv3 executable module in XProtect Remediator, and may disappear in future versions of macOS. It usually isn’t installed as part of macOS, but is installed later as a security data update.

Gatekeeper Configuration Data (GK Opaque)
Latest version: 181, but can instead be 94.
This is an SQLite database in the Data volume in /private/var/db/gkopaque.bundle/Contents/Resources/gkopaque.db and may have been used to provide whitelists for Gatekeeper’s security system, which checks the code signatures of apps. Macs that have never had Catalina or earlier installed normally have the very old version 94, indicating this database isn’t currently used.

Gatekeeper E Configuration Data (GKE), alias Gatekeeper Compatibility Data
Latest version: 1.0 dated 2 October 2019.
This was an SQLite database in the Data volume in /private/var/db/gke.bundle/Contents/Resources/gk.db with an additional file gke.auth, which may have provided whitelists for Gatekeeper’s security system. gke.auth is believed to contain data for checking signed disk images, and seems to have remained largely unchanged since Sierra. gk.db was new in Catalina and hasn’t changed since. Although this is still downloaded and installed, it’s nowhere to be found in Tahoe, and appears to be a historical remnant.

Last updated: 19 September 2025.

Next month we will commemorate the centenary of the death of one of the most influential Nordic artists of the late nineteenth and early twentieth centuries, Christian Krohg (1852–1925). Although he never achieved great international fame, he was a key figure in the artistic development and life of Edvard Munch, was the first professor and director of the Oslo State Academy of Art, a widely-read author and critic, and a social and political campaigner.

Krohg’s background was anything but poor: his grandfather had been a government minister, and his father was a lawyer and statesman. However, his mother died when he was only eight years old, and the oldest of his four sisters, Marie, assumed responsibility for running the household and bringing him up. His family expected him to study law, but his aspiration was to become a painter. The compromise was that he studied law for four years at university, and attended a drawing school.

In 1873, with the death of his father and the completion of his law studies in Oslo, he went to study painting in Karlsruhe, Germany, where he was taught by the great Norwegian landscape artist Hans Gude among others. In 1875, he transferred to the Royal Academy in Berlin, where he was inspired to become a ‘naturalist’ by Max Klinger and Georg Brandes.

Among the earliest of Krohg’s surviving paintings is his Portrait of Lucy Parr Egeberg, 1876, a demonstration of his skills in line and form.

In 1879, on the encouragement of the artist Frits Thaulow, Krohg travelled to Skagen at the northern tip of Jylland (Jutland) in Denmark, where he joined the group of Nordic painters there who were working largely in Impressionist style. Krohg started his first major project to document the lives of the Gaihede family of Skagen over the next decade.

His early painting of Ane Gaihede as a Woman Cutting Bread (1879) was the start of his social realism. Krohg documents her in almost ethnographic detachment. She is aligned in profile, against an almost bare wall, perfectly framed at three-quarter length.

Another major work from this period began his career-long series of paintings of working seamen, in Port Side! (1879). Krohg started this when he was still in Berlin, and completed it when at Skagen that first summer. It was one of two of his paintings exhibited at the Salon in Paris in 1882, and although it didn’t attract much critical attention, its reviews were positive.

Krohg crops this closer, leaving just a few millimetres beyond the tips of his fingers. He adds the dynamics by ensuring that no lines are anywhere near horizontal or vertical, and you can almost feel the heel of the ship’s deck under your feet. The seaman’s oilskins have been patched repeatedly, and have deeply ingrained grime.

In Niels Gaihede Netting (c 1880), another of his Skagen series, he shows the Gaihedes together, with Niels at work on his fishing net, and Ane in the background, staring sternly. Their surroundings are less spartan, but still frugal: the furniture is basic wood, and has seen better days, probably long ago. A clock and some sheets of prints taken from a magazine are the only objects on the blank white wall behind. Niels wears large wooden working clogs, and his trousers have been patched many times.

After his time in Skagen, Krohg started teaching at an art school for women, which in common with others across Europe was trying to address the growing demand from budding women artists, and the conservative attitudes persisting in major academies at the time. Perhaps influenced by this experience, he opened another theme which he was to explore repeatedly, that of illness in the family, with his Sick Girl (1881). The sickness in question is tuberculosis, then prevalent throughout Norway and much of the rest of Europe, King Death as it was nicknamed at the time.

The girl’s face indicates that her end is drawing near. On her lap is a single pale pink rose, its leaves dropped like tears down the blanket covering her legs. He again crops the image closely. This was a direct inspiration for a motif taken up early in the paintings of Edvard Munch, who eventually made around twenty variants of the same theme.

In 1881, Krohg met the Skagen artist Peder Severin Krøyer, and went to live in Paris for a year. He was particularly influenced by the Impressionists, Edouard Manet, and Gustave Courbet, together with the social realism of Jules Breton, Jules Bastien-Lepage, and Léon Lhermitte.

Among the Impressionists, he seems to have been most attracted to the work of Gustave Caillebotte. Krohg’s Portrait of the Swedish Painter Karl Nordström (1882) (above) appears to have been motivated by Caillebotte’s Man on a Balcony, Boulevard Haussmann (1880), below, which in turn was developed from Caillebotte’s earlier painting of his brother as a Young Man at His Window (1875). Curiously, Krohg didn’t paint this in Paris, but towards the end of his time in France, in the artists’ colony of Grez-sur-Loing, in the Spring of 1882.

Perhaps just before Krohg went to Grez, he may have visited Normandy, to paint this interesting little view of a Village Street in Normandy (1882). Its curved recession of umbrellas with disembodied legs is striking.

Krohg then went to stay in Skagen over much of the next couple of years. His sailing painting Hard Alee (1882) was exhibited in the Salon in Paris that year, and was one of the silver wedding gifts from the Norwegian people to King Oscar II and Queen Sophia of Nassau, who were also the king and queen of Sweden, as the countries were in union at the time.

This time his seaman is sailing a small yacht singlehanded. The tiller, his arms, and a line he is holding, trace a bold and dynamic zigzag down the centre of the canvas. Again Krohg is careful to ensure that there is only one horizontal (or vertical) line, that of the horizon.

Krohg’s paintings from this period at Skagen form an absorbing account of life in the artists’ colony there, and several are displayed in the excellent Skagen Museum there. Charles Lundh in Conversation with Christian Krohg (1883) shows this Norwegian painter who lived from 1856-1908, and Krohg’s legs. Lundh stayed in Skagen that summer, living in a house with Krohg, then painted in Persia for five years. Krohg visited Paris again in the Spring of 1883, then returned to Skagen for the summer.

This Self-portrait (1883) of him clutching his huge smoking pipe with a well-used palette in the other hand, shows him at the age of about 31.

It contrasts with The Day After, Self-portrait (1883) which reflects the intensity of the social events held in Skagen, a true confluence of spirits.

References

Skagens Museum, Denmark
Øystein Sjåstad (2017) Christian Krohg’s Naturalism, U Washington Press. ISBN 978 0 295 74206 9.

macOS 26 Tahoe has many smaller enhancements to make life easier. Among them is a novel way of customising folder icons, as explained here.

Traditional custom folder icons

One of the most ancient features in macOS is adding a different icon to a file or folder, by pasting it into the top left of the Get Info dialog for that item. I have detailed how to do that, and how it works, in this article. While that still works, it has some significant limitations and is fiddly.

Another disappointing behaviour in previous macOS is the effect of adding coloured Finder tags to folders, which don’t change the colour of the folder as displayed.

Tahoe custom folders

macOS 26 changes the behaviour of folder icons in three ways:

• Default folder colour is now set in Appearance settings. In most cases, that will be left to use the Theme colour.
• Applying a coloured Finder tag to a folder now changes the colour of that folder, as well as displaying a coloured dot.
• Folders can be customised additionally using the Customise Folder… command in the Finder’s File or contextual menu.

The last of those merits further attention, and an explanation of how it works.

Customising folders

Rather than adding an arbitrary icon to a folder, Tahoe’s custom folders consist of a traditional folder icon with a symbol or emoji superimposed. These are selected from a wide range of vector graphic symbols drawn from Apple’s huge SF Symbols collection, or the standard range of Unicode emoji.

Symbols appear embossed with little difference in tone, so aren’t easy to distinguish unless the folder icon is quite large. This isn’t suitable for use in the Finder’s Column or List views.

The familiar range of emoji is usually clearer and readily distinguishable in most sizes.

Adding a coloured Finder tag to a customised folder makes it even more distinctive, and increases colour contrast with the emoji.

Not only does this look good, but it solves the problems associated with old-style custom folder icons. Copy that folder anywhere within your Mac, and its new look goes with it. Move it into iCloud Drive, and it goes there too. Although Macs and devices running older versions don’t show the custom folder in its full glory, those running OS 26 do. Yes, open Files on your iPhone and you’ll see the custom icon there too.

The only shortcoming that I can find is that, while you can search for specific Finder tags in Spotlight, you can’t search for the symbol or emoji displayed on the folder icon. There is a search attribute Custom Icon, but these folders aren’t considered to have that attribute.

How it works

Tahoe’s custom folders rely on a combination of two extended attributes (xattrs) attached to the folder:

• com.apple.FinderInfo, 32 bytes that is also used in other Finder settings;
• com.apple.icon.folder, new to Tahoe and containing details of the symbol or emoji to be displayed.

Both have to be attached to the folder for it to be displayed correctly.

com.apple.icon.folder is of particular interest, as it has an S flag, and is itself usually displayed as com.apple.icon.folder#S. The S tells macOS that xattr should be preserved during syncing with services such as iCloud Drive. A full list of xattr flags is given in the Appendix. This xattr contains a Unicode string such as
{"emoji":"🔍"}
for an emoji, or
{"sym":"person.crop.circle")
for one of the vector graphics in SF Symbols. The first is self-explanatory, while the second uses the name of that symbol in the SF Symbols library. This currently only supports a subset of the whole library, and my attempts to get it to use others from SF Symbols have so far failed.

Conclusion

macOS has succeeded because of its attention to detail. Tahoe’s new custom folders are an excellent example. Enjoy them!

Postscript

For those who want to disable Tahoe’s default of colouring tagged folders according to one of the tag colours, I’ve now discovered that you can disable that in the control Tint folder based on tags at the foot of the Tags view in Finder’s Settings.

Appendix: Xattr flags

Flags can be upper or lower case letters C, N, P, S or B, and invariably follow the # separator, which is presumably otherwise forbidden from use in a xattr’s name. Upper case sets or enables that property, while lower case clears or disables that property. There are currently five properties:

• C: XATTR_FLAG_CONTENT_DEPENDENT, which ties the flag and the file contents, so the xattr is rewritten when the file data changes. This is normally used for checksums and hashes, text encoding, and position information. The xattr is preserved for copy and share, but not in a safe save.
• P: XATTR_FLAG_NO_EXPORT, which doesn’t export or share the xattr, but normally preserves it during copying.
• N: XATTR_FLAG_NEVER_PRESERVE, which ensures the xattr is never copied, even when copying the file.
• S: XATTR_FLAG_SYNCABLE, which ensures the xattr is preserved during syncing with services such as iCloud Drive. Default behaviour is for xattrs to be stripped during syncing, to minimise the amount of data to be transferred, but this will override that.
• B: XATTR_FLAG_ONLY_BACKUP, which keeps the xattr only in backups, including Time Machine (added recently).

These operate within another general restriction of xattrs: their name cannot exceed a maximum of 127 UTF-8 characters.

If you have a Mac Studio M3 Ultra and want to upgrade it to run macOS 26.0 Tahoe, then I’m afraid you’re going to have wait for Apple to build a new release that will install on your Mac.

I’m very grateful to Ken who has tried unsuccessfully to upgrade from 15.7 to 26.0. There are plenty of others reporting exactly the same: the upgrade goes well until towards the end, then aborts and the Mac is restarted back into 15.7. The problem seems to originate from an error in its neural engine driver.

Having just taken a look through a comparison between kernel extensions shipped with macOS 15.6 and 26.0, there are several Apple silicon hardware kexts that seem to have gone missing in 26.0, although whether that’s the cause only Apple’s engineers should know.

Apple is advising all those affected to put their Tahoe upgrade on pause until it releases a new build that does fully support the M3 Ultra. Until then, 15.7 is the limit for Apple’s most powerful and expensive Macs yet.

Landscape painting was another of the genres that had developed little before the Dutch Golden Age, when it became one of the most popular. It also proved an interesting challenge for its exponents, who had to fill their canvases with a land that was almost completely flat. The favoured solution was to look to the heavens, resulting in the first cloudscapes.

Simon de Vlieger’s Beach View from 1643 uses boats, many figures, and careful composition to swell the land over the bottom of its panel. It shows well, though, how important is the sky, marvellously rendered here, with a small group of white birds shown against the grey of the clouds. De Vlieger was born in Rotterdam, and painted in Delft and Amsterdam, where he was best known for his landscapes.

Jan van Goyen’s View of Dordrecht with the Grote Kirk Across the Maas from 1644 is another example of a low horizon cramming a lot of detail into the foot of the painting, leaving the major part devoted to sky.

The action and excitement, even fear, in Aelbert Cuyp’s Thunderstorm over Dordrecht from about 1645 is in its bolt of lightning, with the cattle lying passive in the fields below.

At about the same time, Jacob van Ruisdael painted his first panoramic landscape, this View of Naarden and the Church of Muiderberg from 1647. Still working on a very wide support orientated conventionally in ‘landscape’ mode, his immense sky is no passive backdrop to the land, but the scene of intriguing cloud formations.

Salomon van Ruysdael filled his panels and canvases with the sky, as in his View of Alkmaar from the Sea from about 1650, where he has turned his panel from the usual ‘landscape’ mode. Clouds had now become subjects in their own right, and differences in their form and texture some of the most important features.

At their best, Cuyp’s coastal landscapes, such as The Maas at Dordrecht from about 1650, are full of rich light, earning him the nickname of the Dutch Claude Lorrain. This shows a passage boat packed with passengers, together with its drummer, below a finely detailed sky.

Cuyp also populated the strip at the foot of his landscapes with farm animals. In his Cows in a River from about 1650, the landscape has been minimised to concentrate on the cattle, although most of his panel is still taken by its striking sky.

Unless backed by elevated dunes, there was no way that an artist could expand thin strips of beach and sea. The dominant towers of cumulus clouds in Adriaen van de Velde’s View of a Beach from 1663-65 have become his subjects.

Jacob van Ruisdael also turned his canvases for these portraits of towering clouds, as in his View of Haarlem with Bleaching Fields from about 1665. The distant town of Haarlem with its monumentally large church of Saint Bavo – works of man – are dwarfed by these high cumulus clouds, the works of God. This motif proved so popular that van Ruisdael painted many variants of the same view, making it now one of the most widespread landscapes across the galleries of Europe.

Other artists like Philip de Koninck marvelled at cloud formations, here in his River Landscape from just after the end of the Golden Age, in 1676.

Among the many new features Apple lists for macOS 26 Tahoe is a new disk image format, Apple Sparse Image Format or ASIF. In that list it appears as a feature for virtualisation, and is explained as: “Create virtualized disk images with a virtualized file format that can be formatted to any kind of file system.”

Yet in the help pages for Disk Utility, the claim goes further: “A modern sparse read/write image. The space it uses on your disk is proportional to the data it contains, making it efficient and general-purpose.” In Apple’s developer documentation for virtualisation, there’s more detail still:
“Apple Sparse Image Format (ASIF) files transfer more efficiently between hosts or disks because their intrinsic structure doesn’t depend on the host file system’s capabilities. The size the ASIF file takes on the file system is proportional to the actual data stored in the disk image.”

This article considers whether this new ASIF disk image format, as implemented in macOS 26.0, is more suitable for general purposes than the other two leading contenders. Should you use ASIF instead of sparse bundle or read-write (UDRW) disk images?

Testing

To assess the performance of these disk images, read and write speeds were measured in macOS 26.0 Tahoe running on a Mac mini M4 Pro with a 2 TB internal SSD. Each disk image was created using Disk Utility, with a single APFS volume in a disk of maximum size 100 GB stored on the internal SSD, with FileVault enabled. Each format was tested using plain APFS, and separately using APFS Encrypted with 256-bit AES.

When each disk image was created and mounted, a single folder was created in it, and the image unmounted. The disk image was mounted again, and a standard write test performed into the folder using Stibium. That writes in random order a total of 160 files ranging in size from 2 MB to 2 GB, totalling 53 GB. Once the write speed had been measured the image was unmounted again and Stibium closed. For the read test the image was mounted again and all 160 files in the test folder were read in random order using Stibium to measure their speed.

Results

Read and write performance for each of the tests are shown in the table, where results are ranked by read speed.

All three disk image formats achieve similar read and write speeds with unencrypted images. There were substantial differences in performance, though, when encryption was used. With encryption, the sparse bundle was faster than both RAW (Read-Write, UDRW) and ASIF. The new format read at exactly half the speed of a sparse bundle, and at 57% of write speed. ASIF with APFS Encrypted was the slowest of the seven tests in both read and write.

Differences in the size on disk of images were small. Empty disks were smallest for sparse bundles and ASIF, and following deletion of all test files, ASIF returned to the smallest size, indicating that it’s the most space-efficient.

Why use ASIF?

If ASIF doesn’t perform any better than existing formats, and any gains in space on disk are small, when and why should you use the new format? To appreciate its strengths, you need to consider how the other two formats work in terms of the file system they’re hosted on, and the file system they run internally.

A sparse bundle stores its contents on many band files inside its bundle. When its internal file system is able to compact free space, used space can be compacted into a minimum number of bundles, and those containing just free space can be deleted. Thus the total size of its bundle will vary according to the space required to store its contents. Coupled with efficient read and write support this results in good space efficiency and performance.

When a Raw Read-Write disk image has an internal file system that is capable of Trimming free space, as APFS and HFS+ can, that process will compact free space within the image. When the image is stored on a host file system that supports sparse file format, as APFS does, the space in the image that is free can be skipped, resulting in a space-efficient sparse file. However, a host file system like HFS+ that doesn’t offer a sparse file format is unable to take advantage of that.

ASIF is claimed to be able to accomplish similar economy of storage space without relying on the host file system’s special file formats, making it more suitable when the conditions required by sparse bundles and Raw Read-Write disk images aren’t available.

Although this new feature has been announced for virtualisation, it’s most probably only going to be useful for those running VMs stored on file systems other than APFS. Prior to the introduction of ASIF, VMs hosted on APFS have used Raw Read-Write style storage which has benefited from sparse file format, whether they’re macOS or Linux. Where ASIF may be of greatest benefit is for VMs run from network shares or cloud services, whose host file system won’t be APFS.

Recommendations

• ASIF should be the disk image format of choice when neither sparse bundles nor Raw Read-Write images can achieve similar economy in host storage space.
• In other circumstances, where sparse bundles or Raw Read-Write images can provide space-efficient storage and full performance, they are still to be preferred.
• At present, ASIF isn’t generally a better replacement for sparse bundles or Raw Read-Write images, particularly when their internal and host file systems are APFS.
• ASIF is likely to be of greatest benefit to those running macOS or Linux virtual machines from network shares or cloud services, where the VM can’t be hosted on APFS.

Apple has just released its weekly update to XProtect for all supported versions of macOS, bringing it to version 5315. As usual, Apple doesn’t release information about what security issues this update might add or change.

This version adds three new detection signatures to its Yara file, two for a new entry named Zuru as MACOS.ZURU.LOAD and MACOS.ZURU.BEACON, and the third as another Soma/Amos component named MACOS.SOMA.SEENA.

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_15-5315

Sequoia and Tahoe systems only

This update has finally 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 5315 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 1100 GMT 17 September 2025, Apple still hasn’t released this via iCloud for Sequoia and Tahoe systems.

Further update: Sequoia and Tahoe systems are now receiving the 5315 update silently, without any change in the version reported by the xprotect tool. So don’t be surprised if your Mac gets updated without the xprotect tool knowing anything about it.

Further further update: over 24 hours after release of this update for older macOS, it has now been made available via iCloud, and the xprotect commands now work, for those Macs that still haven’t updated themselves.

In the distant past, fresco painting was ideal for brightening up the walls or ceiling of a substantial building, but there was also demand for smaller, more portable works of art. Some would have been painted onto animal skins, and were ultimately developed into miniatures in beautiful manuscripts, using the precursors of watercolours. One alternative medium developed most successfully was wax, in encaustic painting.

Characteristically this uses binder that in most ambient temperatures is solid, but becomes liquid paint at higher temperatures, usually no higher than the boiling point of water. This enables the painter to heat mixtures of pigment and binder kept at around 50˚-90˚C (120˚-200˚F), apply them while still hot, and for them to bind the pigment to its ground once the paint cools.

People started to keep bees by around 7000 BCE, and one of their most important products has been the wax from which they build their hives. Beeswax has a typical melting point of about 63˚C (145˚F), a temperature readily achieved by heating water but well above daytime maximum air temperatures experienced where people live, which very seldom reach 50˚C (120˚F). Beeswax was therefore most probably the first binder used for encaustic painting.

Encaustic paint is thus unusual as it doesn’t rely on a chemical process to form the dry paint layer, but a physical change of state, which is fully reversible. Common supports include panels of wood, which originally didn’t have any ground applied. More recently grounds of gesso have been used successfully, but encaustic paints have also been applied to a wide range of supports including dried and fired clay tablets, pots, and sculpture.

One significant limitation with the process of painting using encaustic media is that heated paint tends to be thin and runny. Most artists therefore apply their paint with the support laid flat, and leave their work horizontal until the paint has solidified. Instead of painting stood up in front of an easel, they tend to work lying down.

Although encaustic paintings are susceptible to physical damage and decay, some from before the Christian era have survived, and it’s thought that the medium was used for several hundred or even thousands of years before the birth of Christ. The best-known early encaustic paintings are those made by colonists from Greece and Rome when living in Egypt between about 80-250 CE, particularly those found in the Fayum (or Faiyum) Basin. These were first discovered in about 1615, with most being removed during the nineteenth century and spread across collections in Europe and America. These funerary portraits are among the most haunting images in European art, and demonstrate how skilled encaustic painting can rival other media. It can achieve a remarkable lucency, although this depends on the processing of the beeswax and its ageing.

This Funerary Portrait of a Woman ‘Isidora’ is rendered in fine, close-packed strokes of encaustic wax to model the form, and the eyelashes have been formed by scraping away wax to reveal the underlying black ground. Originally painted on a rectangular cedar board, small squares of gold leaf were applied around her neck, and the board cut down to size to fit the facial area of the woman’s mummy for interment.

Modelling of the skin in this Funerary Portrait of the Boy Eutyches is well in advance of its time, and appears more characteristic of portraits from the Renaissance over a thousand years later.

A tradition of encaustic painting also grew up in early Christian communities, where it was used to create icons for places of worship and the homes of the wealthiest.

This encaustic painting of the Virgin Mary and Child with Saints Theodor of Amasea and George, and Angels was made in about 580 CE for Saint Catherine’s Monastery in Sinai, not far from where the Fayum portraits had been interred.

A few artists continued to paint in encaustic even after the Renaissance, although this has remained a minority pursuit. Giovanni Francesco Romanelli’s painting of Boys Fishing from about 1640 curiously uses cardboard as its support, suggesting it may have been more of an experiment.

The nineteenth century saw a resurgence in the use of more traditional media such as egg tempera. In addition to painting with that, some like Arnold Böcklin returned to try encaustics, here in one of his major works, the first version of Villa by the Sea from 1864.

More followed suit in the twentieth century, including James Ensor, Diego Rivera and Jasper Johns, and today encaustic methods have a small but enthusiastic following.

A couple of weeks ago I estimated how much power and energy were used when performing Visual Look Up (VLU) on an Apple silicon Mac, and was surprised to discover how little that was, concluding that “it’s not actually that demanding on the capability of the hardware”. This article returns to those measurements and looks in more detail at what the CPU cores and GPU were doing.

That previous article gives full details of what I did. In brief, this was performed on a Mac mini M4 Pro running macOS Sequoia 15.6.1, using an image of cattle in a field, opened in Preview. powermetrics collected samples in periods of 100 ms throughout, and a full log extract was obtained to relate time to logged events.

Power use by CPU cores, GPU and neural engine (ANE) are shown in this chart from that article. This tallies against log records for the main work in VLU being performed in samples 10-24, representing a time interval of approximately 1.0-2.4 seconds after the start. There were also briefer periods of activity around 3.2 seconds on the GPU, 4.2 seconds on the CPU, and 6.6-7.1 seconds on the CPU. The latter correlated with online access to Apple’s SMOOT service to populate and display the VLU window.

To gain further detail, powermetrics measurements of CPU core cluster frequencies, active residencies of each core, and GPU frequency and active residency, were analysed for the first 80 collection periods.

Frequency and active residency

Cluster frequencies in MHz are shown in the chart above for the one E and two P clusters, and the GPU. These show:

• The E cores (black) ran at a baseline of 1200-1300 MHz for much of the time, reaching their maximum frequency of 2592 MHz during the main VLU period at 1.0-2.4 seconds.
• The first P cluster (blue), P0, was active in short bursts over the first 1.5 seconds, and again between 6.3-7.0 seconds. For the remainder of the period the cluster was shut down.
• The second P cluster (red), P1, was most active during the three periods of high power use, although it didn’t quite reach its maximum frequency of 4512 MHz. When there was little core activity, it was left to idle at 1260 MHz but wasn’t shut down.
• The GPU (yellow) ran at 338 MHz or was shut down for almost all the time, with one brief peak at 927 MHz.

This chart shows the total active residencies for each of the three CPU clusters, obtained by adding their % measurements. Thus the maximum for the E cluster is 400%, and 500% for each of the two P clusters, and 1,400% in all. These are broadly equivalent to the CPU % shown in Activity Monitor, and take no account of frequency. These show:

• The E cores (pale blue) had the highest active residency throughout, ranging from as little as 30% when almost idle around 5 seconds, to just over 300% during the main VLU phase at 1.4 seconds.
• The first P cluster (purple) remained almost inactive throughout.
• The second P cluster (red) was only active during the periods of highest work, particularly between 1.0-2.4 seconds and again at 6.4-7.1 seconds. For much of the rest of the test it had close to zero active residency.

Taken together, these show that a substantial proportion of the processing undertaken in VLU was performed by the E cores, with shorter peaks of activity in some of the cores in the second P cluster. For much of the time, though, all ten P cores were either idle or shut down.

Load

Combining frequency and active residency into a single value is difficult for the two types of CPU core. To provide a rough metric, I have calculated ‘cluster load’ as
total cluster active residency x (cluster frequency / maximum core frequency)
where the maximum frequency of these E cores is taken as 2592 MHz, and the P cores as 4512 MHz. For example, in the sample period at 2.2 seconds, the P1 cluster frequency was 4449 MHz, and the total active residency for the five cores was 122%. Thus the P1 cluster load was 122 x (4449/4512) = 120.3%. Maximum load for that cluster would have been 500%.

The chart above shows load values for:

• The E cluster (black) riseing to 150-260% during the peak of VLU activity, from a baseline of 20-30%.
• The P0 cluster (blue) which never reached 10% after the initial sample at 0 seconds.
• The P1 cluster (red) spiking at 90-150% during the three most active phases, otherwise remaining below 10%.

Caution is required when comparing E with P cores on this measurement, as not only is E core maximum frequency only 57% that of P cores, but it’s generally assumed that their maximum processing capacity is roughly half that of P cores. Even with that reservation, it’s clear that a substantial proportion of the processing performed in this VLU was on the E cores, with just one cluster of P cores active in short spikes.

Finally, it’s possible to examine the correlation between total P cluster load and total CPU power.

This chart shows calculated total P load and reported total CPU power use. The linear regression shown is
CPU power = 4.1 + (42.2 x total load)
giving a power use of 4,200 mW for a load of 100%, equating to a single P core running at maximum frequency.

Conclusions

• Cluster frequencies and active residencies measured in CPU cores followed the same phases as seen in CPU power, with most of the processing load of VLU in the the early stage, between 1.0-2.4 seconds, a shorter peak at 6.6-7.1 seconds correlating with online lookup, and a small peak at about 4.2 seconds.
• A substantial proportion of the processing performed for VLU was run on E rather than P cores, with P cores only being used for brief periods.
• Visual Look Up used remarkably little of the capability of an M4 Pro chip.

Apple has just released macOS 26.0 Tahoe (build 25A354), together with security updates to Sequoia taking it to 15.7, and for Sonoma to 14.8. As expected, there are no further security updates provided for Ventura, which is now unsupported.

The upgrade to Tahoe is once again provided as an ‘update’ rather than a full Installer app. If you want to run the Installer app to upgrade, download it from the App Store rather than using Software Update. If you’re updating Sequoia or Sonoma and your Mac is capable of running Tahoe, be very careful to select the right update in Software Update.

The Tahoe upgrade weighs in at 7.7 GB for Apple silicon Macs upgrading from a recent version of Sequoia. For Intel Macs it should be 6.1 GB.

On Apple silicon Macs, iBoot is updated to version 13822.1.2. Intel Macs have their firmware updated to version 2092.0.0.0.0 (iBridge 23.16.10350.0.0,0). Safari is version 26.0 (21622.1.22.11.14). The Darwin kernel version is 25.0.0.

Security release notes are also available:

• Tahoe 26.0 lists 75 vulnerabilities fixed, none of which is reported as already being exploited.
• Sequoia 15.7 lists 34 vulnerabilities fixed.
• Sonoma 14.8 lists 38 vulnerabilities fixed.

Useful links

Prepare to upgrade macOS – what you should have done already
What should you do when an update goes wrong?
When you should use Safe Mode, and what it does
What to do when there’s something fundamentally wrong with an Apple silicon Mac
Eclectic Light software updates for Tahoe

Last updated at 1928 GMT 15 September 2025. My apologies for some previous incorrect versions, which were the result of an unintended update.

macOS 26 Tahoe’s big thing is its redesigned interface, with additional variations to appearance modes and its new Liquid Glass effects. Whether you’re installing the upgrade because of those, or in spite of them, allow me to take you on a quick tour of how you can set its interface up, and which controls do what.

There are three sets of controls:

• Appearance mode, Light or Dark, in Appearance settings;
• Display variations to Reduce transparency or Increase contrast, in Accessibility settings;
• Icon & widget style, in Appearance settings.

That comes to a total of more than 20 combinations before factoring in icon tinting colour, so there’s no shortage of choice.

Light mode

There are three overall variations of light mode, depending on those Accessibility settings.

The starting point and default is in light mode without Accessibility, and icon & widget style set to Default. Note the effects of transparency on the menu bar, widgets, the Liquid Glass effect in the left side of the Dock, and the upper row of icons in the Finder window. If you like those, you don’t have to change any settings.

This is light mode with Reduce transparency enabled in Accessibility settings. This disables all Liquid Glass effects and restores the traditional menu bar and Dock. The effect on Desktop widgets is perhaps less beneficial.

In light mode with Increase contrast (automatically coupled with Reduce transparency) enabled, the predominant effect is the outlining of controls within each window, rather than any change in contrast. Colours used by the system, such as the traffic light controls at the top left of each window, and those in themes, are darker, but those elsewhere, as in icons, aren’t changed. The effect here is to make controls clearer rather than actually changing contrast.

Dark mode

Without changing Accessibility and leaving Icon & widget style set to Default, dark mode shows transparency and Liquid Glass effects as you expect. These are again most visible in the menu bar, Dock, and the upper row of icons in the Finder window.

With Reduce transparency enabled in Accessibility settings those transparency and Liquid Glass effects are removed.

Enabling Increase contrast outlines controls clearly, but any changes in system colours are more variable than in light mode.

Icon & widget style

This is new to Tahoe and only affects the rendering of icons and widgets.

Using light mode without any Accessibility changes, the Default setting for Icon & widget style is the baseline, showing icons in their ‘normal’ state.

Dark icon settings in light mode contrasts more but their readability may suffer.

When Icon & widget style is set to Clear, most are decolourised, making them significantly harder to read, and impossible to distinguish in the sidebar of System Settings.

The final option is for Icon & widget style to be Tinted, where they’re rendered in monochrome using a colour of your choice, selected from the popup menu below. On iPhones and other devices that are available in several case colours, some have decided to set tinting to match the case, something you might like to try with an Apple silicon iMac, for example.

However, be careful in both Clear and Tinted styles, as it’s easy to end up making many icons unreadable and almost indistinguishable, here by setting the last of those to Graphite colour. This is one of the obvious drawbacks in Tahoe’s flexibility, in that many combinations of appearance mode, Accessibility settings and icon and widget style degrade its human interface rather than enhancing it. At least you now know what not to try, and how to return it to its defaults.

Summary of controls

• Appearance mode, light or dark, in Appearance settings;
• Display variations to Reduce transparency or Increase contrast, in Accessibility settings;
• Icon & widget styles, in Appearance settings, with Icon, widget & folder colour when appropriate.

Have fun!

Virgil has led Dante into a gorge taking them from the heretics further into the depths of Hell. As they descend, Virgil advises they should take their time so they can become accustomed to the stench emanating from these depths. This allows him to explain to Dante the layout of the parts they are about to enter.

Within the next pit are three sub-divisions, catering for the sins of malice in their different forms. The first ring is for those of violent will, and is divided again into three, for homicides and bandits, for suicides, and blasphemers. Dante’s verbal descriptions of these sub-divisions can readily become confusing, and have been turned into diagrammatic maps by several artists.

One of the most famous is Botticelli’s Map of Hell from 1480-90, in which these lower zones are shown as a funnel at the bottom, leading to the Devil himself.

Jan van der Straet’s diagram from 1587 is similar in form, and packs these zones into the narrow section at the foot.

Dante opens Canto 12 as the pair are scrambling down boulders as if in the Alps, dislodged during the earthquake resulting from Christ’s harrowing of Hell, to meet the Minotaur from Crete.

Like so many of Dante’s beasts, the Minotaur is drawn from classical mythology. This monstrous cross between a bull and human was kept in the labyrinth on Crete, where it was periodically fed with young Greek men and virgin women. For George Frederic Watts, in his painting of The Minotaur from 1885, it represented the worst of Victorian society and its moral values, in the industry of child prostitution flourishing in London at the time.

Dante and Virgil hurry past the Minotaur when they can, and continue their descent through more fallen boulders and scree, to enter the seventh circle, for sins of violence. They are then hailed by one of a group of centaurs armed with bows and arrows. Virgil responds that they will discuss their mission with Chiron, rather than the hot-headed Nessus. Chiron was a centaur in mythology, but one known for his wisdom, and for teaching the young Achilles. Nessus was another centaur, who tried to abduct Heracles’ wife Deianeira and was killed for that, but laid a plot that led to Heracles’ death.

Chiron directs Nessus to aid Virgil and Dante in their passage.

They pass along the rocks beside the damned souls, who are immersed in boiling blood to a depth appropriate to their sins. Dante recognises some as they go: Alexander the Great, Dionysius the Elder and tyrant of Syracuse, one of the d’Este family who was suffocated by his own son. Further on are Attila the Hun, Pyrrhus, Sextus son of Pompey, and a couple of infamous contemporary highwaymen.

Virgil then leads Dante into a strange wood, whose thorn trees form the nests of Harpies. These composite creatures have the heads of humans and the bodies and talons of birds, and live in sub-ring number two. In classical legend, the Harpies inhabited the Strophades, islands where they attacked Aeneas and his companions in Virgil’s Aeneid.

Virgil tells Dante to break a small branch from one of the trees. When he does, the tree screams out in pain, and the wound oozes blood. The tree explains that they were once people, but had taken their own lives. In this case, Dante is talking to the poet Pier della Vigna, who was ruined by envious rivals.

Dante is filled with pity for the spirit, who can only look forward to the Day of Judgement, while they are tortured by the Harpies feeding on their leaves. After learning of another two suicides from Siena and Florence, Dante moves on in profound sorrow.

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 Primavera (c 1482) and The Birth of Venus (c 1485), he was a lifelong fan of Dante’s writings. He produced drawings that 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 engraved. He later began a manuscript illustrated edition on parchment, but few pages were ever fully illuminated.

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 continuing in use. These were followed in 1867 by more illustrations for Purgatorio and Paradiso. This article looks at his paintings.

John Flaxman (1755–1826) was a British sculptor and draughtsman who occasionally painted as well. When he was in Rome between 1787-91, he produced drawings for book illustrations, including a set of 111 for an edition of The Divine Comedy. In 1810, he was appointed the Professor of Sculpture to the Royal Academy in London, and in 1817 made drawings to illustrate Hesiod, that were engraved by William Blake.

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.

Jan van der Straet, also commonly known by his Italianised name of Giovanni Stradano (1523-1605), was a painter who started his career in Bruges and Antwerp in Belgium, but moved to Florence in 1550, where he worked for the remainder of his life. Mannerist in style, he worked with printmakers in Antwerp to produce collections of prints, including an extensive set for The Divine Comedy.

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 325. Here are my solutions to them.

1: Not quite a dogcow functions in six modules from 1991.

2: Suite in three movements replacing 1 from 2004.

3: Yoga position with syncopated music, but it wasn’t the sequel to 1-2-3.

The common factor

I look forward to your putting alternative cases.

When Apple launched its new iPhone 17 range last week, it also announced a major change in their security. This article tries to explain what that means, and whether Apple intends building it into future Macs.

Handling of memory is an important facet of security, and securing that should eliminate plenty of vulnerabilities from Apple’s operating systems. For example, the single vulnerability fixed in Sequoia 15.6.1, and known to be actively exploited, resulted in memory corruption from processing a malicious image file. Many of those fixed in 15.6 also cite memory problems in their cause, such as corruption, out-of-bounds and use-after-free errors. Apple’s research indicates that some of the vulnerabilities used in the most sophisticated attacks, particularly those against iOS, could have been prevented by making memory handling more secure in the first place.

Over the last few years, Apple has focussed attention on making memory handling safer. Starting in iOS 15, it introduced a new interface known as kalloc_type to be used throughout the kernel and all kernel extensions. This requires Apple’s engineers to adopt its new features, and by iOS 16 it’s estimated that 95% of the kernel-space codebase in iOS had been converted. This has been fed through into macOS from Ventura onwards.

Although kalloc_type has helped, more is needed if memory handling is going to as safe as Apple wants, in what it terms Memory Integrity Enforcement. Unlike most other security measures, the principle of this is relatively simple: to allocate and control memory using secure tags. When a kernel extension, for example, requires some memory, it’s provided with a secure tag. When it wants to access any of that memory, the kext then has to provide the tag with its request. The tag is then checked and access only granted if the tag is successfully validated for the address requested.

This can be used to prevent one of the commonest types of vulnerability, accessing memory beyond that allocated in a buffer overflow. As that memory request is out-of-bounds of the memory allocated, the secure tag provided won’t extend to cover that, and the request is refused. Another common type of vulnerability is when code requests memory that has already been freed, in use-after-free access. MIE prevents that as the secure token is invalidated when that memory is freed, so the request is refused.

While the principle underlying MIE is simple, its implementation is more complex. One obvious problem is that it imposes significant overhead to memory allocation and access. The only way to work around that is to implement it in hardware, hence its current limitation to devices using Apple’s new A19 and A19 Pro chips, the first to offer that support. These come with additional features for Arm’s Enhanced Memory Tagging Extension, an option from the Armv8.7 instruction set architecture, and not yet available in an M-series chip for Macs. If you look for FEAT_MTE4 among the hardware options in sysctl (shown easily in Mints, for example), there’s no mention of it in Apple’s latest M4 chips. Additionally, for apps to support MIE, they have to opt in to enable hardware memory tagging, a feature that’s only available for now in the iPhone 17 range, including the iPhone Air.

Critics have pointed out that MIE only tackles some vulnerabilities, but Apple’s analysis of recent real-world exploits used in malware shows how the combination of defences can now disrupt the chains many rely on. By achieving that early in a chain, Apple argues that those developing attacks will be forced to redevelop the whole of that exploit chain. Neither is MIE completely new, as other operating systems like GrapheneOS, popular on Google’s Pixel devices, have already been using their own implementation of similar protection. Apple claims that those have shortcomings it has addressed in implementing MIE for iPhones.

Apple hasn’t yet made any announcement about whether or when MIE might be coming to its M-series chips using in Apple silicon Macs. I suspect we’re unlikely to see the debut of an M5 complete with Neural Accelerated GPU and hardware support for MIE in Apple’s Halloween Mac event, and more likely with macOS 26.3 early next year. Of course, MIE doesn’t protect against everything, but it should make life significantly harder for those intending to attack us.

Further reading

Apple on kalloc_type
Apple on Memory Integrity Enforcement
Arm on Enhanced Memory Tagging Extension
Apple on Enhanced Security for app developers.

In this second and concluding article showing the seasons in paintings, I resume with one of the treasures of the Louvre in Paris. Towards the end of his life, Nicolas Poussin’s hands developed a severe tremor making painting fine details very difficult. Despite that, his final years saw some of his greatest landscape paintings, and standing head and shoulders above those is his series of the Seasons, believed to have been painted between 1660-64.

Each of these is both a fine painting of an idealised landscape, together with narrative referring to a Biblical story. They not only move through the seasons of the year, but through the times of the day, starting in the early morning of Spring, and ending at night for winter, a device used later by others including William Hogarth.

Spring starts at the beginning of the Bible, with the story of Adam and Eve in the Garden of Eden. Eve is persuading Adam to join her in an apple, the opening step of the Fall.

For Summer, Poussin chose the story of Boaz discovering Ruth gleaning after the wheat had been cut in his fields, as told in the Book of Ruth. In its contrasting Italian coastal setting, this shares common ground with earlier paintings of the Brueghels.

Poussin refers to a story from the Book of Numbers for Autumn, in which Israelite spies visited the Promised Land, and brought back grapes as evidence of what lay ahead.

Winter returns to the Book of Genesis, to show the great flood, with lightning crackling through the sky, and survivors trying to escape the rising waters. This also demonstrates Poussin’s lifelong dread of snakes: one is slithering up the rocks on the left, and there is another in the water, although not visible in this image.

Early in William-Adolphe Bouguereau’s career he was commissioned to paint a series showing The Four Seasons (1854-55) for the music pavilion in the garden of the Monlun banking family in La Rochelle. In keeping with their opulent surrounds, these were painted on gold grounds, a layer of gold leaf into which the artist embossed a geometric pattern to result in this unusual appearance. He painted a series of young women with seasonal attributes. These include the flowers of Spring, with their reference to Flora, sheaves of ripened corn (Ceres), a bacchante with her goblet of wine and thyrsus, and wrapped up for winter with snow on her clothing.

The greatest series of mythological allegories of the seasons is that painted in the final years of Eugène Delacroix’s life. These were commissioned by the Alsacian industrialist Frederick Hartmann, and completed just before the artist’s death in 1863. Although considered to be allegories, in that they don’t directly show each season, they are unconventional in using stories from classical myths that are tied into the seasons.

For Spring, Delacroix chose Eurydice Bitten by a Serpent while Picking Flowers (Eurydice’s Death), in which the bride Eurydice is bitten on the foot (or ankle) by a snake immediately after her wedding, and dies.

For summer, the story is another tragic myth of Diana Surprised by Actaeon, again set in the season shown. Actaeon stumbled across the goddess bathing when he was out hunting; as a result of his unintentional glimpse of her naked body, he’s turned into a stag and killed by his own hunting dogs. He’s already in transition, with antlers growing from his head.

Delacroix’s choice for autumn draws on the common association between that season and wine, with Bacchus and Ariadne. After being abandoned on the island of Naxos by Theseus, who had promised to marry her, Ariadne is discovered by the young Bacchus. Here, the god has just arrived and is helping the gloomy and despondent Ariadne to her feet. They then fall in love and marry.

For the final season of winter, the artist chose Juno Beseeches Aeolus to Destroy Ulysses’ Fleet, with a slight conflation between the stories of Ulysses and Aeneas. In the Aeneid, Juno offers Aeolus a nymph as a wife if he will let loose his winds on the fleet of Aeneas. That he does, and the fleet is driven onto the coast of North Africa by a winter storm.

At the end of the nineteenth century, Alphonse Mucha made several series of prints showing the four seasons. Among these is The Four Seasons, probably from around 1897-1900. These make interesting comparison with Bouguereau’s more conventional paintings above.

A Masque for the Four Seasons, painted in oils between 1905-09, was possibly Walter Crane’s last major work in oils. This draws on Botticelli’s Primavera, in its frieze before a dense woodland background, and copious seasonal wild flowers. Its four Grace-like women are colour-coded from the Spring on the left.

The seasons are also a pervasive feature of much of East Asian art, and I close with a relatively modern example.

Araki Jippo 荒木 十畝 painted Birds and Flowers of Four Seasons 四季花鳥 on silk in 1917, which makes a fascinating comparison with the landscapes of de Momper.

For the last three months, since Apple released the first developer beta of macOS 26 Tahoe, I’ve been fairly busy updating my apps so they’re ready for its release. This quarter of the year is usually quite busy, but the changes brought by Tahoe have required more work than any version of macOS so far. This article provides checklists of every one of my apps and command tools that I believe should be compatible with macOS 26, and in most cases I have tweaked and rebuilt to ensure that.

The first problem posed by Tahoe was its rough handling of app icons that it didn’t like, because they deviated from its standard square with rounded corners. This isn’t something to be ignored, as if you can’t recognise apps in the Dock, how can you use them?

Here are two icons for the same app viewed in Tahoe. The left one uses a traditional AppIcon.icns icon image, while that on the right is the same circular PNG that has been applied using Icon Composer and added as a .icon file for Tahoe. So every supported app has required a new icon to be designed for it, and incorporated into a new build. Here’s part of my beauty parade.

Unfortunately, the moment you rebuild an app with its new icon, its whole interface is also rebuilt to Tahoe’s new standards. Those not only include all those infernal rectangles with rounded corners, but many controls and elements are larger than in Sequoia. While this is implemented intelligently so as not to upset layouts when running in older versions of macOS, Tahoe’s new look can wreak havoc with windows and dialogs.

This demo, Mallyshag, looks the same in Sequoia above, but has become a mess in Tahoe (below) because of those changed control dimensions.

Those three buttons are significantly wider, so now overlap one another and are wider than the text box below. They need a careful overhaul before they’re ready for Tahoe. Conversion can also have unexpected side-effects: for example, I’ve had some selectable text fields changed to be editable as well.

Here are the 31 updated apps that I have equipped with a new icon and adjusted their interface for Tahoe:

• Alifix version 1.4
• Apfelstrudel version 1.6
• Cirrus version 1.16
• Cormorant version 1.6
• DelightEd version 2.4
• Dintch version 1.8
• DropSum version 1.2
• Dystextia version 1.9
• Fintch version 1.4
• LogUI version 1 build 70
• Metamer version 1.6
• Mints version 1.21
• Nalaprop version 1.4
• Podofyllin version 1.4
• Precize version 1.16
• Revisionist version 1.10
• SilentKnight version 2.12
• Skint and SkintM version 1.09
• Sparsity version 1.4
• Spotcord version 1.0
• SpotTest version 1.1
• Spundle version 1.9
• Stibium version 1.2
• SystHist version 1.21
• The Time Machine Mechanic (T2M2) version 2.03
• Ulbow version 1.11
• UTIutility version 1.4
• Versatility version 1.1
• xattred version 1.6
• XProCheck version 1.7

There are also my three macOS virtualisers for Apple silicon Macs, which require more than an overhaul. However, I regularly use these in Tahoe and believe they’re fully compatible, even if their icons will disappoint:

• Viable version 1.0.12 (b12)
• ViableS version 1.0.12 (b12)
• Vimy version 0.7 (fourth beta)

I intend working on those in the coming months, to update them and cast them into fresh interfaces.

I have also tested five of my command tools, and believe they too are fully compatible with Tahoe:

• alisma version 4
• blowhole version 11
• cintch version 3
• cmpxat version 4
• unorml version 5

At least they don’t have custom icons.

So that was the summer of 2025, in more nutshells that I had expected. I hope you still find these useful, and will report any problems you encounter.

Those of us in the northern hemisphere are just sliding into the autumn/fall, as those in the southern are entering Spring. This weekend I celebrate the seasons with the help of an array of some of the finest painters of their time. This article shows sets up to that painted by Pieter Brueghel the Younger. Tomorrow I conclude from the most famous set of all, completed by Nicolas Poussin shortly before his death in 1665, up to the early twentieth century. In each case, I show the seasons in chronological order, starting with Spring, and ending with winter.

The earliest paintings in modern Europe depicting seasons were calendar miniatures in Books of Hours like those of the Limbourg Brothers, such as the famous Très Riches Heures of the Duc de Berry, from about 1411-1416.

One of the early artists who transferred the theme to full-size easel paintings was Giuseppe Arcimboldo, who made several of his marvellous anthropomorphic portraits in sets of four. Less well-known, but more ambitious, is his Four Seasons in One Head from about 1590. He combines different passages to represent the seasons in turn. Spring is in the flowers on the body, summer in the sheaves of ripe corn, autumn in the fruits decorating the hair, and winter in the leafless face and branches.

Although best known for these anthropomorphic paintings, Arcimboldo was by no means their only exponent. At about the same time, Joos de Momper painted anthropomorphic landscapes, in which figures appear from crafted landforms. These come together in an undated series of four allegories of the seasons.

The most conventional platform for depicting the seasons was, inevitably, in landscape paintings. In another series, de Momper painted one of the finest landscape sets between about 1612-15. Each of these is carefully composed with a checklist of different details: trees and their foliage, domestic animals, birds both species and activity, human dress and activity, weather, sky, and so on. This provides much common ground with traditional East Asian paintings of the seasons, as shown in tomorrow’s article.

The Bruegels had also been working for many years on their series showing the seasons. Pieter Bruegel the Elder (c 1525-1569) had been commissioned to produce designs for prints in the mid 1560s, but after his early death the incomplete project was taken over by Hans Bol (1534-1593) and completed as prints in 1570. Pieter Brueghel the Younger (1564–1638) used those as the basis for one of his standard series of paintings, of which two complete sets are known to survive. The images below are of the set in the National Museum of Art of Romania, in Bucharest.

In Spring, gardeners are planting out a formal Italianate flower-garden, a sight that was probably inspired by Pieter Bruegel the Elder’s visit to Italy. It has been suggested that this composition is even more ingenious, in showing March in the foreground, April behind, and May at the furthest end of the garden.

Summer shows the conventional country sight of the wheat harvest, as more fully developed in other paintings by the Brueghels, and one of the most familiar with its golden stooks and bustling activity.

The composition used for Autumn is taken from Bol’s print, although here the number of figures has been reduced to simplify and clarify. The villagers are busy slaughtering and preparing animals, as stooks of corn are laid up in lofts.

Winter draws on several earlier paintings showing skating on ice, and is influenced by those and Bol’s composition used in his 1570 series of prints.

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

1: Not quite a dogcow functions in six modules from 1991.

2: Suite in three movements replacing 1 from 2004.

3: Yoga position with syncopated music, but it wasn’t the sequel to 1-2-3.

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.