Apple has released its weekly update to XProtect, bringing it to version 5318. As usual, it doesn’t release information about what security issues this update might add or change.

This version makes several changes to the Yara definition for MACOS.COMPLIANTPIRATE.DEFU, but doesn’t add any new detection rules.

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_15-5318

Sequoia and Tahoe systems only

This update hasn’t yet been released for Sequoia and Tahoe via iCloud, but hopefully will be shortly. If you want to check it manually, use the Terminal command
sudo xprotect check
then enter your admin password. If that returns version 5318 but your Mac still reports an older version is installed, you should be able to force the update using
sudo xprotect update
However, if the regular update has been installed in the old location, XProtect is likely to update its new location from that. There’s nothing you can do to force that, but it may well explain why your Mac seem to have updated itself.

Before the Dutch Golden Age, painting scenes at night had been restricted to religious and other narrative works, and very few if any landscapes had been depicted during the hours of darkness. After all, what’s the point of a view if it’s all dark and you can’t admire it?

The Dutch Republic changed that, in part because it was in Northern Europe, where for several months each year it’s mostly dark, and these nocturnes had novelty value. Among those of the middle class who could afford to, it was fashionable to cover the walls inside your house with paintings, and nocturnes, known then as maneschijntjes (moonshines), certainly brought variety to those collections.

Aelbert Cuyp’s view of the Sea by Moonlight from about 1648 is one of the earlier maritime nocturnes, something of a sub-sub-genre that must have been sought after. Unlike many others, this appears to be faithful to the original light.

During the 1640s, Aert van der Neer, a landscape painter in Amsterdam, started experimenting with his first nocturnes, and came to specialise in them.

His River View by Moonlight from about 1650-55 shows a bustling village on a river, with several boats under way and two windmills in the distance. The moon appears to be depicted faithfully in terms of size, without the common tendency to exaggerate that as a result of the Moon Illusion. Surviving studies for some of these nocturnes demonstrate that van der Neer initially sketched a landscape in daylight, and based the detail in his finished studio painting on that.

In about 1655, he painted this finely detailed River Landscape with Moonlight, with a larger moon lighting clouds dramatically.

Some of his best nocturnes are lit by a combination of the moon and the warmer light from a fire. This undated Estuary Landscape by Moonlight uses light from both sources to great effect. Landscape details are shown largely in silhouette, and lack internal detail except in the group gathered around the fire in the foreground. Van der Neer is unusually faithful to reality in this monochrome, the result of the severely impaired colour vision we all suffer in conditions of low light, when there’s insufficient to enable colour vision using the cone cells in the human retina.

At some stage, van der Neer started painting more destructive fires, including this undated Fire in Amsterdam by Night, leading to another sub-sub-genre that was taken up by others.

In mid 1652, Jan Abrahamsz Beerstraaten seems to have witnessed the destruction by fire of part of the centre of Amsterdam, which formed the basis of his studio painting of The Old Town Hall of Amsterdam on Fire, 7 July 1652 (1652-55). Local inhabitants are walking in orderly queues to boats, in which they escape from the scene. This may have been the same fire painted by van der Neer, above.

Egbert van der Poel specialised in these brandjes,, and probably painted more than any other artist in history. He moved to Delft in 1650, and four years later was a victim of the massive explosion in a gunpowder store there on 12 October 1654. That killed one of his children, and he moved again to Rotterdam.

It has been thought that most of van der Poel’s Fire of a Church with Staffage and Cattle from 1658 is a carefully-composed composite of his experiences. A small church at the edge of a village is well ablaze, and the inhabitants are abandoning it, taking all the possessions they can, including their horses and livestock, and leaving the fire to burn itself out.

Van der Poel’s undated A Fire at Night shows a similar scene and composition, set this time on the bank of a canal.

One established exception to this is van der Poel’s Fire in De Rijp of 1654, completed in 1662. This shows a fire that worked its way through more than eight hundred buildings in the town of De Rijp during the night of 6 January 1654. This left only the northern section of the town standing and inhabitable, and resulted in more casualties than did the more famous explosion in Delft at the end of that year.

Doubt is cast on this received account of van der Poel’s work by sketches such as this, of The Fire in the Nieuwe Kerk, Amsterdam, in 1645, made in front of the motif using washes with touches of pen and brown ink. Perhaps he was the first ‘ambulance chaser’ who travelled out to sketch fires, from which he later painted his famous brandjes in the studio.

For the non-specialist like Jacob van Ruisdael, winter was an ideal opportunity to explore the effect of negative images, where objects that would normally be seen as dark on a light background were reversed to white on dark.

Van Ruisdael painted at least two such landscapes featuring trees. Both are now known by the same name, and are believed to be from the same decade. This Winter Landscape (c 1660-70), in the Mauritshuis, picks out frosted leaves in the half-light of dusk or dawn, by a hamlet at the water’s edge. In the far distance, to the left of the buildings, there is a church with a spire.

The other version of Winter Landscape (c 1660-70) is in Birmingham, Alabama. With similar sky, cloud, lighting, and composition, the water here appears to have frozen over. The frost on the trees is just as delicately handled.

If you ever encounter an error when checking an APFS volume using First Aid in Disk Utility or fsck_apfs, you won’t be informed of the path and name of the item responsible, but given its inode number, in an entry like
warning: inode (id 402194151): Resource Fork xattr is missing for compressed file

The inode number given can only be resolved to a path and file/folder name if you also have a second number giving the volume for that item. As that will be for the volume being checked at the time, you should be able to identify that immediately. The only time that you might struggle to do that is with items in a snapshot; those should, I think, be the same as the volume they are taken from. However, as snapshots are read-only, there’s probably little point in pursuing errors in them.

To resolve these in my free utility Mints, open its inode Resolver using the Window / Data… / Inode menu command. Drag and drop another file from the same volume onto that window.

The Resolver will then display that file’s volfs path, such as
/.vol/16777242/1241014

All you need do now is paste the inode number given in the warning or error message in Disk Utility or fsck_apfs, into the Inode Number box at the top of the Resolver window, and click the Resolve button. Mints then looks up information for that inode number on the same volume, using GetFileInfo, and displays it below.

One drag and drop, a paste, and a click to discover what APFS is complaining about.

Command line

You’ll sometimes see Terminal’s find command with the option -inum recommended as a way to convert from an inode number to a regular path. Although you can do that, it’s easier to use the command GetFileInfo instead. For that you’ll need the full volfs path, including the volume number.

To find the volume number, use my free utility Precize, and open another file on the same volume. The second line in its window gives the full volfs path for that file. Copy the start of that, leaving the second number, the inode, such as
/.vol/16777238/

Alternatively, you can use the stat command as given below.

In Terminal, type
GetFileInfo
with a space at the end, and paste the text you copied from Precize. Then copy and paste the inode number given in the First Aid warning, to assemble the whole command, such as
GetFileInfo /.vol/16777238/402194151

Press Return, and after a few seconds, you should see something like
file: "/Users/hoakley/Library/Mobile Documents/com~apple~CloudDocs/backup1/0MintsSpotlightTest4syzFiles/SpotTestA.rtf"
type: "\0\0\0\0"
creator: "\0\0\0\0"
attributes: avbstclinmedz
created: 05/17/2023 08:45:00
modified: 05/17/2023 08:45:00
giving the full path and filename that you want.

GetFileInfo is one of the oldest commands in macOS, and has been deprecated as long as anyone can remember. I suspect that Apple is still trying to work out what can substitute for it.

Get a volfs path for a file

Use Precize to run this the other way around: open the file and read the path in that second line. To copy the whole of it, press Command-2.

The simplest ways of obtaining inode numbers and so building volfs paths in Terminal are using the -i option to the ls command, and for individual items using stat:
ls -i lists each item in the current directory, giving its inode number first, e.g.
22084095 00swift
13679656 Microsoft User Data
22075835 Wolfram Mathematica
and so on;
stat myfile.text returns
16777220 36849933 -rw-r--r-- 1 hoakley staff […] myfile.text
where the first number is the volume number, and the second is the inode number of that item, or /.vol/16777220/36849933.

Almost all who paint in oils use conventional brushes, but there’s a significant minority who sometimes, or frequently, use different tools to apply and shape the paint layer. Of those, the most popular are palette knives, generally used to move and mix paint on the palette. Others have used the other end of the brush stick to incise, or their fingers.

Marie Bashkirtseff’s painting of a class in the Académie Julien in Paris in 1881 demonstrates how oil painting should be done by the textbook. The artist, shown in her self-portrait in the centre foreground, is using a long-bladed palette knife to prepare the paint on her palette. At her feet, on an old sheet of newspaper, are her brushes, all with handles of typical length, and the pupil behind her is using a maul stick to rest her right hand while painting with her brush.

Gustave Courbet applied his paint using a palette knife for some of his paintings. This has been identified from the facture in some of his paintings of caves that he made from about 1864, including The Grotto of Sarrazine near Nans-sous-Sainte-Anne above.

Another enthusiast for painting with a knife was Auguste Renoir.

In 1866, Renoir painted his friend Jules Le Coeur and his Dogs in the Forest of Fontainebleau. This is unusual among his works, as it was preceded by two studies, and all three were made using the palette knife rather than brushes. This makes it most likely to have been painted before Renoir abandoned the knife and returned to the brush, by the middle of May 1866.

Renoir returned to the technique in The Mosque, also known as Arab Festival, in 1881. Small strokes of bright colour and energetic work with the palette knife give it a strong feeling of movement, and it so impressed Claude Monet that he bought it from Durand-Ruel in 1900.

Anna Althea Hills’ Fall, Orange County Park (1916) is a classic and highly accomplished plein air painting that appears to have been made with extensive and deft use of the knife, particularly in the foreground.

Perhaps the most famous artist who is known to have painted with his fingers is Leonardo da Vinci.

This Annunciation, painted in oil and tempera on a poplar panel, is generally agreed to be one of the earliest of Leonardo’s own surviving paintings. When it was painted is in greater doubt, but a suggestion of around 1473-75 seems most appropriate. There are numerous pentimenti, particularly in the head of the Virgin. Its perspective projection is marked in scores in its ground and Leonardo used his spontaneous and characteristic technique of fingerpainting in some of its passages.

Finally, some painters are well-known for their use of brushes with exceptionally long handles. These enabled them to stand back, sometimes almost on the opposite side of their studio, get an overall view of their canvas, and paint from the same distance as a viewer.

Like all plein air painters, Paul César Helleu (1859–1927) shown in John Singer Sargent’s An Out-of-Doors Study from about 1889, is using brushes with handles of modest length. His canvas is fairly small, and he’s working close-in while clutching a brace of brushes in his left hand. Some designed for use when painting in front of the motif have even shorter handles, but when back in the studio Helleu would almost certainly have opted for longer.

Whistler was renowned for using brushes with handles over one metre (39 inches) long, and appears to have used them when painting Symphony in White No. 1: The White Girl in 1862 on a canvas just over two metres (78 inches) tall. He reworked it between 1867-72 to make it more ‘spiritual’ and reduce its original realism.

Early in his career, Joaquín Sorolla established his reputation of painting ‘voraciously’, often using brushes with extremely long handles and large canvases. Although Sewing the Sail from 1896 may look a spontaneous study of the effects of dappled light, Sorolla composed this carefully with the aid of at least two drawings and a sketch, and given its 2.2 metre (87 inches) height, he was almost certainly using brushes of similar length.

You’ve just run First Aid in Disk Utility, or fsck_apfs, and that reports warnings or errors. What should you do next?

Failure to unmount

By far the most frequent error encountered in Disk Utility’s checks results from its inability to unmount a volume before it can start testing. While this is reported as an error, and it prevents the checks from running, it can sometimes be solved by manually unmounting the volume in question. It normally doesn’t indicate anything sinister, and is simply frustrating.

Repeat in Recovery mode

If the warnings or errors were reported on your current boot Data volume and you ran that check in normal user mode, consider starting your Mac up in Recovery mode to repeat the check there.

Although macOS does an impressive job of performing checks on a live volume, it’s more reliable and more likely to be able to perform any repairs needed in Recovery mode, when the Data volume isn’t mounted and live. When there, if you prefer, you can still use fsck_apfs in Terminal.

The other case where checks may be best made in Recovery are those on an active Time Machine backup volume. That’s because those can be difficult to unmount before running the checks, although that is possible as long as a backup isn’t being made at the time, or Spotlight indexing taking place. The sure way to avoid those is to do so in Recovery mode.

Warnings or errors?

Any remarks about problems or irregularities encountered during checks should make explicit whether they are warnings or errors, and it’s essential to make a clear distinction between them.

Warnings are observations that could have significance, or might be perfectly normal in the circumstances. Only an APFS engineer is likely to be able to tell the difference. Among the commonest are those reporting missing xattrs for compressed files:
warning: inode (id 113812826): Resource Fork xattr is missing for compressed file
Experience is that those aren’t related to any consequent errors, and you should be able to leave those alone.

Errors are abnormalities that do have more significance, and might have the potential to cause further problems. Where possible, First Aid or fsck_apfs should attempt to repair those, most probably by performing “deferred repairs”. Those are normally minor errors that it already has plans to attend to when that volume is next mounted, the time that APFS normally performs its routine maintenance.

Snapshots

These are read-only copies of the file system metadata at a previous instant in time, and are associated with retained storage blocks. They aren’t part of the active volume, and their metadata are separate. As they’re read-only, any warnings or errors are most unlikely to be fixed, so you have a choice of leaving that snapshot to be deleted routinely by age, or deleting it early yourself.

Snapshots are made by backup utilities including Time Machine, which are required by Apple to have a mechanism that will delete them automatically after a set period. In the case of Time Machine, that’s when the snapshot is over 24 hours old. Snapshots aren’t backups, but augment regular backups, and stand in for them when backup storage isn’t available. In general, there seems little point in deleting a snapshot early just because there’s a reported warning or error for it, as that won’t affect the health of the active volume.

Identifying faulty items

Warnings and errors related to specific files or directories are normally given with an item id, which should be their inode number. To go any further, you’ll need to convert that to a path and file/directory name. You should therefore copy and paste all reports into a separate file as reference. Resolving an inode to a path and item name is detailed in this article.

In many cases involving items that can be resolved to an existing path, the faulty item is in one of the hidden folders such as .Spotlight-V100 for Spotlight indexes, or .DocumentRevisions-V100 for the document version database. In the former, rebuilding Spotlight’s indexes may resolve the problem, but you’re unlikely to be able to do anything about the latter.

If the inode resolves to a regular file, deleting that can remove the problem, but when you try restoring that file from a backup you may discover the backup has the same problem. Getting to the bottom of a recurrent file system error might require the knowledge and skills of an Apple engineer. Consider reporting this using Feedback, as it should then help iron out any remaining bugs in APFS.

You should also consider whether your Mac might be running old third-party software that is causing recurrent errors. Normally, products should work at a higher level that isolates them from the file system itself, but there are some surprising exceptions. If you can identify a cause, please inform the developers of that software so that it can be fixed.

Old versions of APFS

One potentially dangerous practice occurs when an older version of APFS changes a newer file system. APFS back in High Sierra and Mojave knew nothing of boot volume groups, firmlinks, or many of the features of more modern versions of APFS. If you really must run different versions of macOS on the same Mac, or shared external storage, avoid such version conflicts, and never run an older version of Disk Utility or fsck_apfs on a newer APFS container or volume.

When a group of devils armed with long hooks threatens Dante, Virgil hurries him along towards the next rottenpocket in Hell. They work their way around some of the damage wrought by Christ’s harrowing of Hell following his crucifixion. With those devils still hanging around, they then reach a pit of boiling tar, in which the spirits of barrators are trapped. These had traded in public office and bought influence in courts of law.

The devils pull out one of the souls for Dante and Virgil to talk to, but quickly return to hacking with their hooks.

Unlike others, he springs free and escapes their lunges as he plunges back into the pitch.

Dante and Virgil leave the devils attacking other barrators, and walk on in silence. Dante reflects on one of Aesop’s fables about the frog, the rat and the hawk. He blames himself for the tormenting of the devils behind them, but as he looks back he sees them on the wing again heading towards them. As they cross into the next rottenpocket, they realise the pack of devils can’t pursue them beyond that point.

Next are hypocrites, who are dressed up in hooded habits like monks. Although those are coloured bright gold, they’re weighted with lead, forcing the hypocrites into eternal labour against the mass of their clothes.

Dante meets two Bolognese friars, Catalano de’ Malavolti and Loderingo degli Andalò, who formed a fake religious order. They point out a figure staked out naked on the ground, who is Caiaphas, the High Priest of Jerusalem who advised scribes and pharisees that Christ’s death would be a good solution.

Virgil moves Dante on towards the damaged crossing to the next rottenpocket for thieves. After negotiating their descent, Dante sees its pit full of snakes, binding the hands of the souls there and covering their naked bodies.

A snake strikes one of the sinners at the back of the neck, causing the ghost to burst into flames then turn into ash, which falls onto the ground and reconstitutes itself.

There they talk with one of the thieves by the name of Vanni Fucci, a black Guelph from Pistoia near Florence who had stolen holy objects from a chapel and betrayed an accomplice for execution in his place. The snakes then take charge of him, winding their coils around his neck and body, and putting him into a reptile straightjacket.

Dante and Virgil move on and meet a centaur.

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 being used. 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 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.

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 328. Here are my solutions to them.

1:

Click for a solution

Angels

Schwabe’s painting shows a chain of angels emerging from a belfry.

2:

Click for a solution

Daemons

Doré’s engraving shows The Demons Threaten Virgil, from his illustrations to Dante’s Inferno.

3: James Bond, Jason Bourne, George Smiley, Modesty Blaise

Click for a solution

Agents

They are each (secret) agents: James Bond from Ian Fleming, Jason Bourne from Robert Ludlum, George Smiley from John le Carré, and Modesty Blaise from Peter O’Donnell.

The common factor

Click for a solution

They are each run by launchd from property lists in folders titled LaunchAngels (new in Tahoe), LaunchDaemons and LaunchAgents.

I look forward to your putting alternative cases.

For many years, I believed what the log command told me, that log entries could contain any of the 26 or more fields available, although they didn’t. It was only as I was developing utilities like LogUI that I discovered that log entries come in (at least) four types, each with its own format and set of fields. This article is a guide to those, and how they are displayed in LogUI.

Entry fields

Those available in the OSLog API are fewer in number than appear in log command output, and include some of limited interest. Those not exposed in LogUI include:

• store category, which is invariably disk storage here.
• format string, that used to format the contents of messages. This was introduced following serious security leaks in High Sierra.
• components, linking in with the format string.

LogUI displays each entry using the same order of fields and colour-coding. Although they can’t all be seen together in any single log entry, the overall sequence is:

Standard levels are given as text, and chosen from one of the following: fault, error, notice, info, debug, undefined. These are only used with Regular log entries, not other types. LogUI always includes debug level entries when they’re available.

The four types of entry are:

1. Regular
2. Activity
3. Boundary
4. Signpost.

Regular entries

These are normally by far the most common, and are seen throughout the processes and subsystems writing log entries. They normally contain up to the following fields:
datestamp, [1], activity ID, category, level, sender, process, process ID, subsystem, thread ID, message

These examples include:
datestamp, 1, activity ID, category, level, sender, process, process ID, subsystem, thread ID, message
which is fairly normal.

Activities

These mark specific activities, and vary according to the process and subsystem. Some are valuable waypoints, and all are recognisably shorter than most regular entries, containing only the following fields:
datestamp, [2], activity ID, parent activity ID, sender, process, process ID, thread ID, message

These are examples of one of the most valuable activities reported, indicating a mouse-click or tap. They’re also complete, as they consist of:
datestamp, 2, activity ID, parent activity ID, sender, process, process ID, thread ID, message

Boundaries

These are rare but instantly recognisable because of their brevity. They consist of just three fields:
datestamp,[3], message

Two of the most important are the announcement of the start of kernel boot:

and adjustment of the internal clock:

These are also easy to search for, as their message contains the distinctive === string.

Signposts

By default, LogUI extracts omit Signposts, but if you tick the Show Signposts box before loading log entries, they will also be displayed. In parts, they can outnumber regular entries, and are unlikely to provide you with meaningful information unless you know internal details of their process. Each Signpost adds three type-specific fields, shown after the process ID:
datestamp, [4], activity ID, category, sender, process, process ID, signpost ID, signpost name, signpost type, subsystem, thread ID

These examples come from the most prolific user of Signposts, SkyLight for WindowServer, and contain
datestamp, 4, activity ID, category, sender, process, process ID, signpost ID, signpost name, signpost type, subsystem, thread ID
Note there’s no message field, as their meaning is determined by the signpost fields.

Datestamps and times

The OSLog API doesn’t currently give access to Mach times, only to opaque Date variables. From those, LogUI’s datestamps give:
year–month–day hour:minute:second.microsecond+timezone

All times and time zones given are those current when LogUI obtains that extract, not when that entry was written. This can become extremely confusing when clocks change to and from {summer time, daylight time, daylight saving time, daylight savings time, DST}, and when passing through time zones, and great care is required when reading logs containing such corrections. LogUI tries to make this easier, but care is still required.

If you have used the log command, you may be aware that can return Mach times as ticks, offering precision down to the nanosecond. This currently isn’t possible when using the OSLog API, but given the relatively slow clock of Apple silicon Macs, it’s no longer as useful as it used to be with Intel’s nanosecond Mach ticks.

Censorship

By default, all data in message fields is censored to protect the privacy of the user. This replaces chunks of text with the dreaded <private>, and can render many entries devoid of any useful information. In recent versions of macOS log privacy can be removed by installing a profile. However, that doesn’t apply retrospectively, only to log entries collected after the profile has been installed.

Removing privacy also increases the size in storage of log entries, and may reveal sensitive information. As soon as you have completed acquisition of the logs you need with privacy removed, you should therefore remove the profile, to allow normal censorship to resume.

A suitably signed profile is here: enablelogprivatedata

To install the profile, unzip the archive into a convenient folder and double-click it. You’ll be informed by a notification that you need to review the profile to install it. Open System Settings and select Device Management in its View menu, or search for it. Follow the instructions given there to install and activate it.

Sadly, this doesn’t cover all censorship. Some systems require additional configuration changes, for example CFNetwork diagnostic logging. Jeff Johnson explained how to enable that, but Apple has since blocked that, and I don’t know of a practical alternative. In some cases, additional detail can be obtained by adjusting log settings.

Summary

A short practical summary of LogUI’s log entries is provided in its Help book.

In yesterday’s article I showed excerpts from two cycles of paintings of the journey of life, by Nicolas Poussin and Thomas Cole, and started the epic series of 34 images by Louis Janmot that constitute his Le Poème de l’âme (Poem of the Soul). The last painting of his depicted the child growing up in an idyllic country landscape in Spring.

The child’s family are at home during a thunderstorm, shown by flashes of lightning at the window. Grandmother reads a psalm to calm the spirit, while the mother and another young woman sit and sew. Father (a self-portrait at the age of thirty) looks on with concern. An even older woman, perhaps the great-grandmother, sits in the shadows near the window.

The couple have grown now, and find themselves walking along a path by the university. In the niches alongside the path are its professors, each offering false learning that might replace their faith. That learning is represented by the combination of papers and a lighted candle. In the niche closest to the viewer is the figure of death itself, its niche decorated with skeletons. The land is rocky and barren, with a wizened tree, where an owl is perched.

Still dressed in their gowns from their First Communion at church, the two sit together by a pond, with high mountain peaks in the distance. The boy is stroking a dove, a symbol of peace, while the girl strokes a panther, indicating tamed passions. They both hold a lily, for purity, which separates and unifies them.

In a revisit of Jacob’s Ladder, the pair fall asleep in the woods, and dream of a perpetual cycle of nine angels ascending and descending a staircase leading towards God in heaven. The angels each carry a symbol of the arts, such as a musical instrument.

The couple now face life’s challenges, symbolised by the ascent of a mountain, a task they accomplish together. So they achieve the ideals of life, both earthly and spiritual. This also indicates their exploration of space, and the world in which they live.

Later, when they have reached adulthood, she bids him farewell when she is called to ascend to heaven.

Now a man, returned to earth alone, his spirit back in heaven, he kneels before a wooden cross decorated with a garland of flowers that she left him. (It’s said this refers back to flowers she wore at their First Communion, but no such flowers appear in the paintings.) He pines for her memory, as breaks in the cloud cast bright sunlight down on patches of the earth.

Janmot’s story concludes in his series of charcoal drawings, where the man falls in love, but is abandoned. He then experiences doubt and falls into evil ways in an orgy. He suffers, and ages as a result of his sins, but his plight is taken by his mother to Jesus and the Virgin Mary in heaven for their intercession.

The intercession was successful, and a team led by an angel arrives to address the man’s plight. The woman’s corpse is despatched into the waves, perhaps in a form of burial at sea. The angel’s team consists of two other women, who sit and read from books held open by putti. At their feet are symbolic animals: a lion (strength), fox (cunning), and sheep (the sacrifice of Jesus Christ). Above them are three more putti, bearing symbolic objects including a large fish-hook, whose meaning is obscure.

The man is welcomed back at a heavenly Eucharist – the title is from the early words of the service, in Latin. Angels swing censors, there are rows of pious kings and clergy, and in the distance, descending a flight of steps, is the figure of Christ himself, bearing a lamb on his shoulders. The group at the right foreground contains the man’s soul, who looks directly at the viewer. With this, Janmot’s epic is concluded.

Just over a decade after Janmot completed that series of 34 images, Walter Crane condensed his account of the journey of life into a single painting.

Crane’s allegorical narrative of life as a bridge appears unique to him. It shows a newborn baby arriving in the hand of a winged angel in a white punt/gondola, left of centre. The baby is handed over to a mother or nurse, fed at the breast at the bottom left corner, walking up the steps, and learning at the top. Children play, then grow into young adults, and marry as they reach the top of the bridge. Throughout this runs the thread of life.

The mature adult in the middle of the bridge (by its keystone) then ages steadily, bearing the whole globe during the descent. He then gains a long white beard and walking stick during the descent into old age, finally dying, his body being placed in the black punt/gondola, where it is attended by the angel of death. Grieving relatives stand on the shore and make their farewells, one cutting the thread securing the boat to the shore with a pair of traditional scissors.

Crane explained the theme of his Bridge of Life (1884) as “fortune and fame pursued and ever eluding the grasp; til the crown perhaps is gained, but the burden of the intolerable work has to be borne.” It was first shown at the Grosvenor Gallery, then toured venues in the East End of London during a period of social and labour unrest.

My final series is the second of two Friezes of Life assembled by the Norwegian artist Edvard Munch. He seems to have started thinking about this during the 1880s, but it wasn’t until the early 1890s that it crystallised in his personal notebooks. He talked about building them into a ‘symphony’ in early 1893, and by the end of that year exhibited his first self-contained series of images in Berlin, under the title A Human Life.

During 1893 and 1894, Munch painted most of the works that were to form his first Frieze of Life, exhibited in March 1895, in Ugo Barroccio’s gallery in Berlin. His own explanation is that “the paintings are moods, impressions of the life of the soul, and together they represent one aspect of the battle, between man and woman, that is called love” (Heller, in Wood, 1992).

Munch later assembled his second and mature version, titled Frieze: Cycle of Moments from Life, and exhibited it in Berlin in 1902. It then consisted of twenty-two paintings, arranged in four sections. Here I show a small selection of some of the better-known paintings from that.

The Boston version of Summer Night’s Dream (The Voice) (1893), included in the 1895 version of the Frieze, was here titled Evening Star. It shows Munch’s lover ‘Mrs Heiberg’ at the edge of the Borre Woods, to the north of Åsgårdstrand. This features a brilliant golden-yellow pillar of reflected moonlight on the fjord, forming a distinctive ‘i‘ that appears in other paintings. This work initiates a sequence in which Munch gives his personal account of the process of falling in love.

Evening on Karl Johan shows the crowd from his painting Anxiety in an autobiographical scene. During Munch’s affair with ‘Mrs Heiberg’, he had arranged to meet her on Karl Johans Gate, the long, straight main street in the centre of Oslo. As he waited for her, his anxiety grew, exacerbated by crowds of people walking towards him.

Munch’s later depiction of this greatly foreshortens the perspective of this section of the street from the Royal Palace towards the Storting (parliament building), a distance of around 300 metres. This packs the pedestrians together and, coupled with their nightmarish faces, enhances its troubling feeling of anxiety.

A later section closes with The Scream, showing the isolated figure of Munch before the distant city of Oslo, its fjord with ships at anchor, and the surrounding hills. As the artist’s notes explain:
I was walking along a path with two friends. The sun was setting. I felt a breath of melancholy. Suddenly the sky turned blood-red. I stopped and leant against the railing, deathly tired, looking out across flaming clouds that hung like – blood and a sword over the deep blue fjord and town. My friends walked on – I stood there trembling with anxiety, and I felt a great, infinite scream pass through nature.

By the Deathbed (1895) is Munch’s painting from memory of his sister Sophie resting in her deathbed in 1877, when she was 15 and the artist wasn’t quite 14 years old. She died of tuberculosis, an unfortunately common event at the time. Munch explained that, when painting from memory like this, he depicted only what he could remember, and was careful to avoid trying to add details he no longer saw.

Sophie is seen from her head, looking along her length to her feet, her figure compressed into almost nothing by extreme foreshortening. Her deathbed resembles the next step, in which her body will be laid out in a coffin prior to burial. More than half the painting is filled by the rest of the family, father with his hands clasped in intense prayer. At the right is the mother, who had died of tuberculosis herself nearly nine years earlier.

References

Janmot’s Le Poème de l’âme: Wikipedia (in French).
Janmot’s Poem of the Soul 1
Janmot’s Poem of the Soul 2
Janmot’s Poem of the Soul 3
Janmot’s Poem of the Soul 4

Munch’s Frieze of Life
The Munch Museum, Oslo.
Wood, Mara-Helen (ed) (1992) Edvard Munch, The Frieze of Life, National Gallery Publications. ISBN 978 1 857 09015 4.

Before macOS Tahoe, the biggest sticking point in virtualising macOS on Apple silicon Macs has been their lack of support for the App Store. From the outset this has been an ironic limitation. Here’s some of Apple’s most advanced technology running on its latest hardware, and it can’t even run the apps that Apple sells, only those supplied direct by their developers.

VMs can now have iCloud and iCloud Drive support, Messages, FaceTime, FileVault, and plentiful shared folders, but the one thing they have lacked that renders them useless for many users and many purposes is that can’t sign into Apple services, particularly the App Store. Some apps, including those in Apple’s iWork suite, will run in a VM despite it being unable to sign into your account, but you can only window-shop in the App Store, and most of its apps will simply refuse to run, even free ones.

I’ve long suspected that this is an example of Apple Commercial constraining Apple Engineering. To be useful, macOS VMs would have to be exempted limits on the number of Macs authorised to access services, and that could open up the possibility of third-parties bypassing FairPlay and the digital rights controls embedded in macOS. It must be deeply frustrating to those working on virtualisation, knowing that it could be done but won’t be.

So the only substantial new feature for macOS virtualisation in Tahoe is the introduction of ASIF disk images. For the time being, I’m not sure they’re going to change much for most of us who host our VMs on local APFS storage. As they still don’t enjoy proper API support, I don’t see any compelling reason to rush into their use, unless you want to host your VMs in the cloud.

Upgrading to Tahoe has, though, drawn attention to problems lurking for those who created VMs of 50 GB or smaller, who now want to enlarge them for this purpose.

Resizing VMs

Don’t skimp when creating a new VM. Give it a useful size, as its Disk.img is stored as a sparse file, so won’t take all that disk space unless you fill it to capacity. I now make my default VMs 100 GB to ensure there’s ample free for updates and anything else that might arise.

If you do have a treasured VM that’s too small, you may well be able to increase its size, either using Disk Utility or the hdiutil resize command tool if you prefer. To do this, start by duplicating your VM in the Finder. That creates a clone, and lets you fall back to the unaltered original if the resizing goes horribly wrong.

To resize the disk image using Disk Utility, you first have to move it out from inside its VM bundle, easily done in the Finder. Then in Disk Utility’s Images menu use the Resize… command, select that Disk.img and enter its new size. Add a little, around 8%, to allow for overheads, and let Disk Utility get on with the work.

Here’s Disk Utility inside this Tahoe VM, showing its 50 GB virtual disk.

I then resized it to just over 100 GB.

Here it is afterwards, now showing a full 100 GB.

I gather from others that resizing doesn’t always work. If you can’t get it to, then the only way forward is to create a new VM with the larger capacity and copy across the contents of your old VM. One obvious way to make that simpler and more thorough would be to use Migration, either during configuration of the new VM, or shortly afterwards.

I’m very grateful to Michael for telling us of his success in migrating from a small to a larger VM in Tahoe. I’m also more than a little jealous, as I’ve so far been unable to get it to work for me.

I’m also mystified as to how two macOS VMs running concurrently on the same Mac could establish a connection to support the file transfers required in migration. Neither can expose its virtual folders as shared folders for the other, and in any case shared folders are strictly circumscribed. Sharing them over AFP runs into a quirk of their bridged networking, that both of the VMs will default to using the same network IP address. In my failed tests, the destination Migration Assistant was able to recognise the source, but failed to connect to it successfully.

For the moment macOS virtualisation hasn’t made any substantial improvements in Tahoe. It still can’t sign into Apple services, and AI remains unavailable. Let’s hope the next year brings more and better, and realises more of its potential.

Series paintings of times of the day and the seasons have been popular, but those trying to depict the whole of life are unusual and challenging. This weekend I look at some of the better attempts to tell the story of the journey of life. Because some of these series consist of more than five paintings, I here show selections of those longer accounts.

One of the earliest painted accounts of life is Nicolas Poussin’s series The Seven Sacraments. His first version of this was started in about 1636 as a commission for his patron and mentor Cassiano dal Pozzi, and was completed four years later.

The first in the series shows The Baptism of Christ, as an unusual example of a baptismal scene. The white dove of the Holy Spirit above the figure of Christ is one link across some of the others in the series.

The white dove reappears in Poussin’s genteel account of Marriage.

The series is completed by Extreme Unction, showing the sacrament being administered to a cadaveric man as his family are gathered around his deathbed.

Although several of William Hogarth’s series were biographical, such as his first two of A Harlot’s Progress (c 1731) and its compliment A Rake’s Progress (1732-5), none attempted to depict the whole journey of life from birth to death.

The next is probably Thomas Cole’s Voyage of Life, painted in 1839-42. Like Poussin before him, Cole wasn’t satisfied with painting this cycle of four phases. When he was in Rome in 1842, fearing that he wouldn’t see his series again, nor be allowed to exhibit it, he painted a second version, now in the National Gallery of Art in Washington, DC, and shown here. He had already painted a precursor cycle, The Course of Empire, in 1833-36, telling the story of an idealised civilisation, inspired by Byron’s poem Pilgrimage (1812-8).

Cole’s first series The Voyage of Life was commissioned to show a Christian allegory of the stages of life. He divided this into childhood, youth, manhood, and old age.

Childhood establishes the scene: the lush coastal undercliff, rich in flowers and the vibrant green of vegetation. A boat has emerged from a large cave in the cliff, symbolising the mother’s birth canal and the process of birth. A young baby is standing in the boat, with an angel at its tiller. A carved angelic figure forming the prow holds out an hourglass as the symbol for time.

In Youth, the young man has taken the helm of the boat, leaving the angel on the bank. The morning light is bright, and the weather fair. The young man is navigating the boat along the river, through lush waterside meadows and avenues, towards a distant vision of a celestial temple. The coastal cliffs are now in the background on the right, and in the centre distance is a rocky mountain spire.

By Manhood, the hero has noticeably matured, and his boat is on a fast-flowing river just approaching dangerous rapids passing through a rocky chasm. It is now dusk, and the angel is watching over from a break in the dark and forboding clouds. The man no longer holds the tiller, indeed the rudder is missing altogether, but both hands are clasped in prayer, as he looks anxiously up towards the heavens. In the foreground on the right are twisted trees, splintered by storms, with autumnal leaves.

Old Age shows the man in the boat far older, bald and with a grey beard. His boat is now in placid waters at the coast again, making no way. The boat itself is battered, its figurehead missing. He sits in the boat talking with the angel, who beckons him up through a parting in the black clouds, to a distant angel, far up in the heavens, rising through beams of sunshine towards brightness at the top left.

The painter who came closest to creating an epic in his works must be Louis Janmot, whose series Le Poème de l’âme (Poem of the Soul) consists of no less than 34 images, of which the first eighteen are painted in oils, and the remaining sixteen are in charcoal. Miraculously, the complete series is still together in the Musée des Beaux-Arts in Lyon, France. Although the captions don’t report it, each of the oil paintings is 130-145 cm in height, and 140-145 cm in width, although I have also seen them stated as being much larger, approximately 394 x 500 cm.

Like Blake and Dante Gabriel Rossetti, Janmot was also an accomplished poet, and his series is accompanied by an epic poem of nearly three thousand lines. He had a deep Catholic faith, and both the poem and the paintings are framed within his beliefs.

The series opens in heaven, with the mystical formation of a human soul, shown in symbolic form as a baby. This takes place under the watch of the Holy Trinity, although the three figures surrounding the newborn soul include a woman who represents love. Around this tight group are seemingly endless ranks of angels.

The newborn soul is brought down to earth by its guardian angel. This view, midway between heaven and earth, shows the succession of newborn souls being taken down to earth in the centre, and the judgement of the dead taking place at the side. The souls of the virtuous are seen being accompanied back up to heaven by their guardian angels, at the left. On the right are those destined for hell.

Below, on the right, is the figure of Prometheus bound, being attacked by an eagle. Prometheus is a strange figure from classical mythology to appear in this series, but a strong symbol of eternal suffering.

This is set by the Lake of Moras, where the mother sits with the newborn soul on her lap. Its guardian angel is kneeling in prayer for the mother and the soul of her new child. This painting combines the images of the annunciation to the Virgin Mary, and the Virgin Mary with the infant Jesus, in a unique way.

As the child grows up, Janmot represents it as a duality of boy, shown here in pink, and girl, in white symbolising purity and innocence. The pair are shown at play, picking flowers, in an idyllic country landscape during the spring.

This mystical duality continues through most of the rest of the oil paintings. At times, the pair appear to be brother and sister, or even lovers, but as we will see in tomorrow’s sequel, in the end they represent the earthly body (boy) and the spirit (girl). They are usually colour-coded, the boy wearing pink, and the girl white.

References

Poussin’s Sacraments
Cole’s Voyage of Life
Janmot’s Poem of the Soul 1
Janmot’s Poem of the Soul 2
Janmot’s Poem of the Soul 3
Janmot’s Poem of the Soul 4

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

1:

2:

3: James Bond, Jason Bourne, George Smiley, Modesty Blaise.

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.

Every self-respecting file system identifies files and directories using numbered data structures. In most modern file systems, those data structures are known as inodes, and their numbers are inode numbers, sometimes shortened to inodes. The term is thought to be a contraction of index node, which certainly makes sense, but is lost in the mists of time.

In any file system, for example an individual APFS volume, the inode numbers uniquely identify each inode, and each object within that file system has its own inode. Whatever else the file system might do, the inode number identifies one and only one object within it. Thus one invariant way of identifying any file is by referencing the file system containing it, and its inode number.

HFS+

The Mac’s original native file systems, ending most recently in Mac OS Extended File System, or HFS+ from its origins in the Hierarchical File System, don’t use inodes as such, and don’t strictly speaking have inode numbers. Instead, the data structures for their files and folders are kept in Catalogue Nodes, and their numbers are Catalogue Node IDs, CNIDs.

With Mac OS X came Unix APIs, and their requirement to use inodes and inode numbers. As CNIDs are unique to each file and folder within an HFS+ volume, for HFS+ they are used as inode numbers, although in some ways they differ. CNIDs are unsigned 32-bit integers, with the numbers 0-15 reserved for system use. For example, CNID 7 is normally used as the Startup file’s ID.

Although not necessarily related to CNIDs, it’s worth noting that the Mac’s original file system MFS allowed a maximum of 4,094 files, its successor HFS was limited to 65,535, and HFS+ to 4,294,967,295. Those are in effect the maximum number of inode numbers or their equivalents allowed in that file system.

APFS

Unlike HFS+, APFS was designed from the outset to support standard Posix features, so has inodes numbered using unsigned 64-bit integers.

Strictly, the APFS inode number is the object identifier in the header of the file-system key. Not all unsigned 64-bit integers can be used as inode numbers, though, as a bit mask is used, and the number includes an encoded object type. APFS also makes special allowance for volume groups consisting of firmlinked System and Data volumes, to allow for their inode numbers to remain unique across both volumes. Officially, those allow for a maximum number of inode numbers of 9,223,372,036,854,775,808, either in single APFS file systems, or shared across two in a volume group.

Every file in APFS is required to have, at an absolute minimum, an inode and its associated attributes, shown above in blue, including a set of timestamps, permissions, and other essential information about that file.

There are also three optional types of component:

• although some files may be dataless, most have data, for which they need file extents (green), records linking to the storage blocks containing that file’s data (pink);
• smaller extended attributes (yellow), named metadata objects that are stored in a single record;
• larger extended attributes (yellow), over 3,804 bytes in size, whose data is stored separately in a data stream.

Interpretation

When looking at inode numbers in volume groups, they can be used to determine which of the firmlinked file systems contains any given file. Both volumes share the same volume ID, and files in the System volume have very high inode numbers, while those in the Data volume are relatively low. I have given further details here.

Inode numbers are more generally useful in distinguishing files whose data appears identical, and the behaviour of various methods of linking files.

Copying a file within the same file system (volume) creates a new file with its own inode number, of course. However, duplicating a file within the same file system results in an APFS clone file, with a distinct inode, although it shares common data, so their inode numbers are also different.

Instead of duplicating everything, only the inode and its attributes (blue and pink) are duplicated, together with their file extent information. There’s a flag in each clone file’s attributes to indicate that cloning has taken place.

A symbolic link or symlink is merely a pointer to the linked file’s path, and doesn’t involve inode numbers at all. Because of that, changing the linked file’s name or path breaks its link. Finder aliases and their kindred bookmarks do contain inode numbers, so should be able to cope with changes to the linked file’s name or path, provided it remains in the same file system and doesn’t change inode number.

Hard links are more complex, and depend on the way in which the file system implements them, although the fundamental rule is that each object that’s hardlinked to the same file has the same inode number. According to Apple’s reference to APFS, this is how it handles hard links.

When you create a hard link to a file (blue), APFS creates two siblings (purple) with their own IDs and links, including different paths and names as appropriate. Those don’t replace the original inode, and there remains a single file object for the whole of that hardlinked file.

Inode attributes keep a count of the number of links they have to siblings in their link (or reference) count. Normally, when a file has no hard links that’s one, and there are no sibling files. When a file is to be deleted, if its link count is only 1, the file and all its associated components can be removed, subject to the requirements of any clones and applicable snapshots. If the link count is greater than 1, then only the sibling being removed is deleted.

Easy access

Inode numbers are readily accessed using command tools in Terminal. For example, ls -i lists items with their inode numbers shown. One free utility that displays full information about inode numbers and much more is Precize.

The volume ID is given as the first number in the volfs path, and the second is the inode number of that file within that. Note that the File Reference URL (FileRefURL) uses a different numbering system, and the Ref count of 1 indicates this file has no hard links.

The appearance of new objects or unexpected phenomena in the sky was an event of great significance in the past, and often considered to be a portent of the future, good or bad. This article considers the few that were recorded in paintings, and starts with the most famous of all, the star of Bethlehem that appears in many depictions of the birth of Christ.

The linked stories of the birth of Christ in a shed at Bethlehem, and the subsequent adoration of the infant by three wise men, kings or Magi “from the east”, are among the most popular and enduring among paintings in the Christian canon. The outlines given in the Gospels of Luke, chapter 2, and Matthew, chapter 2, have conventionally become elaborated.

Three wise men had seen a new star, possibly a comet or an unusually bright planet, which they believed would lead them to the birth of a great prophet. They travelled by the guidance of that star, to arrive at Bethlehem. There they found the newborn Christ with Mary his mother, paid homage to him in the shed in which the holy family was lodging, and presented their gifts of gold, frankincense, and myrrh.

Giotto’s Adoration of the Magi from about 1305 shows the star as a celestial ball of fire streaking across the sky, and the three wise men pay their respects to the newborn Christ and his mother.

Above Bosch’s view of the local Brabant countryside in his Adoration of the Magi of 1490-1500 he places a more modest and stationary star shining bright over its distant city, as shown in the detail below.

Blake’s version of the Adoration of the Kings is conventional in showing the three wise men presenting their gifts to Jesus and his parents. At the left, outside, shepherds are tending to their flocks of sheep beneath a stylised star, and at the right are the ox and ass.

There remains controversy over what celestial event might have occurred at the time.

Very few paintings show known events in the sky, and I know of only one depicting a full solar eclipse.

Although many painters, particularly the Impressionists, have shown fleeting effects of light and the occasional rainbow, Enrique Simonet took the opportunity of a solar eclipse on 30 August 1905 to paint his Eclipse (1905). This was visible across eastern and northern Spain between about 1300 and 1320 UTC, and this painting is one of its few remaining records.

Realistic paintings of comets are also rare, and unimpressive.

Generally acclaimed as William Dyce’s finest painting, Pegwell Bay, Kent – a Recollection of October 5th 1858 (c 1858) shows this bay on the Kent coast, during a family holiday visit: a coastal scene worked up into a large finished oil painting. Although not easily seen in this image, there’s a small point of light high in the middle of the sky which is Donati’s comet, not due to return until 3811. Couple that with the inclination of the sun and the state of the tide, and you should be able to place this view precisely in both time and space, and confirm that it does indeed show this bay on 5 October 1858.

A few paintings show impossible celestial events.

John Martin’s painting of The Deluge from 1834 has two points of reference: the Biblical account of the flood, and Martin’s personal belief in prior catastrophe. As the sciences became ascendant during the nineteenth century, some educated people believed that in the past there had been an alignment of the sun, earth, and moon, and the collision of a comet resulting in global flooding. This was promoted by the French natural scientist Baron Georges Cuvier, and subscribed to by Martin.

True to form, his painting is dark and apocalyptic: near the centre, tiny survivors are just about to be overwhelmed by an immense wave bearing down at them from the left and above. The misaligned sun and moon barely penetrate the dense cloud, and to the top right is a melée of rock avalanche and lightning bolt. This was awarded a gold medal at the Paris Salon of 1835.

Several of Paul Nash’s surrealist landscapes show the moon in its phases, among them Landscape of the Vernal Equinox (III) from 1944, which presents the impossible view of a full moon and the sun visible close together and just above the horizon.

Browsing through the /System/Library folder in macOS Tahoe you’ll no doubt be surprised to see a new folder, between LaunchAgents and LaunchDaemons, named LaunchAngels. This article takes a preliminary look at what’s in there, and what these new additions to Apple’s bestiary do.

Launch Agents and Launch Daemons

These have been used in macOS for a great many years, probably since the introduction of launchd in Mac OS X 10.4 Tiger in 2005. These folders contain property lists for:

• Launch Daemons are standalone background processes managed by launchd, running as root before the user logs in, and communicating indirectly with user processes, normally by XPC. They’re not allowed to connect to WindowServer.
• Launch Agents are also managed by launchd, but normally run on the user’s behalf, communicating with other processes and daemons. Although they can have GUI interfaces, they’re normally minimal.

Before you have logged in, launchd runs services and other components specified in property list files in the LaunchAgents and LaunchDaemons folders in /System/Library, and in /Library. Those in /System/Library are all part of macOS, owned by Apple, and locked away on the SSV, but those in /Library can include those installed by third party products, although these days more are being enclosed in app bundles. As they’re run before the user logs in, those work for all users, so are global services.

These property list files contain keyed settings to determine what launchd does with what. Although they can contain many other key-value pairs, two most important ones are ProgramArguments (or Program), which tells launchd what to run, and RunAtLoad, which determines whether launchd should run the service or app whenever your Mac starts up and it loads those agents and services. Other keys determine whether the agent/service should be kept running at all times; if that is set, if it crashes or is otherwise terminated, launchd will automatically start it up again. That’s important for background services that apps rely on to function.

Launch Angels

As of macOS 26.0.1 there are three Launch Angels, each with a property list in /System/Library/LaunchAngels. Those relate to three apps now in /System/Library/CoreServices,

• AccessibilityUIServer,
• GameOverlayUI,
• PosterBoard.

AccessibilityUIServer is an addition to the Accessibility process group, and is listed in the processes in Activity Monitor as Accessibility. It thus runs in the background, supporting Accessibility features in Tahoe. These might perhaps extend the Accessibility enhancements for UIKit provided in UIAccessibility to macOS.

The other two apps aren’t run at load, so must be run on demand. GameOverlayUI appears to be responsible for providing the new Game Overlay features, and I suspect that PosterBoard is responsible for Lock Screen customisation. A key set for each of these in their property list is _ExperimentalNonLaunching, suggesting that these are still in test.

Apple describes Game Overlay as allowing “players to stay in the game when it matters most. Players can easily adjust settings, connect with friends, and check out the latest In-App Events and supported Game Center features, all without leaving their game.”

RunningBoard

What’s most unusual, and may be new with Tahoe, is that all three property lists include settings for RunningBoard and its life cycle management. These are the keys

• Managed, to require life cycle management by RunningBoard, set to true for all three;
• Reported, presumably to set RunningBoard to report its use of system resources, again set to true for all three.

I’m not aware of any similar RunningBoard settings for property lists in the LaunchAgents or LaunchDaemons folders, though.

Conclusions

• Launch Angels are currently three new services for macOS 26 Tahoe, run through launchd using property lists in /System/Library/LaunchAngels.
• Those extend Accessibility, provide Game Overlay, and probably support Lock Screen customisation.
• They are unusual in having RunningBoard settings in their property lists.
• At least for the moment, Apple doesn’t intend anyone else trying to use Launch Angels of their own.
• As the LaunchAngels folder is on the SSV, it isn’t exploitable. Whether a LaunchAngels folder might work in the main Library folder is a different question, though.

In the autumn of 1888, Christian Krohg married Oda Engelhardt, his former pupil, in Oslo. Although their relationship appears to have been open and stormy at times, Krohg now had a partner and a family to paint.

In the summer of 1888, the Krohgs returned to Skagen in Denmark where he painted Oda Krohg (1888). Although not as clinical as his series of portraits of the Gaihede family there, he uses the same profile pose, with his subject looking straight ahead as if in an identity photograph. That contrasts with his informal and sketchy facture.

Krohg’s three-quarter length Portrait of the Painter Oda Krohg, née Lasson (1888) is a marked contrast. Although still quite formal in its composition, Oda is here shown in her role as a ‘princess of the Bohemians’ that sadly overshadowed her own art.

Over this period Krohg had been working on his next major painting, The Struggle for Existence, also translated as The Struggle for Survival (1889). It shows Karl Johan Street in Oslo in the depths of winter, almost deserted except for a tight-packed crowd of poor women and children queuing for free bread. This is the central street in the capital city, and three years later was to be the setting for Edvard Munch’s famous painting of Evening on Karl Johan Street.

These people are wrapped up in patched and tatty clothing, clutching baskets and other containers in which to put the food. A disembodied hand is passing a single bread roll out to them, from within the pillars at the left edge. That was yesterday’s bread; now stale, the baker is giving it away only because he cannot sell it. A policeman, wearing a heavy coat and fur hat, walks in the distance, down the middle of the icy street, detached from the scene.

On this pessimistic note, Krohg’s ‘naturalism’ or social realism came to an end.

The Krohgs spent the summer of 1889 not at Skagen, but in the coastal resort of Åsgårdstrand, about sixty miles (100 km) south of Oslo. Nearly ten years later, Edvard Munch was to buy a summer house here. The Krohgs’ son Per, their second child, was born there that summer, and was almost certainly the model for In the Bathtub (1889). This shows the ceremonial surrounding the bathing of a newborn baby, with the mother and women relatives providing endless advice and taking charge of the event.

In the autumn, the family travelled to Copenhagen, Denmark, where they lived until early summer of 1890. They made a short visit to France, where Krohg was awarded a bronze medal at the Exposition Universelle in Paris. At this time, he had been working as a journalist and teaching, particularly at the painting school run by Harriet Backer.

When he was living in Copenhagen, Krohg painted one of his few works in Impressionist style, View over Frederiksberg, Copenhagen (1890), but decided not to further pursue landscape painting.

Instead, Krohg painted some history of contemporary relevance. Returning to his seafaring theme, his next successful work was a period drama dear to the Nordic heart: Leiv Eirikson Discovering America (1893). Leif Erikson was Nordic and had probably been one of the Norse inhabitants of Iceland between about 970-1020. The son of Erik the Red, who colonised Greenland, Leif visited Norway in about 999, and according to the Icelandic Sagas went on later to discover Newfoundland in Canada. When Krohg painted this, no archaeological evidence had been discovered to support the sagas, and that didn’t follow until 1960.

Krohg’s choice of motif drew on growing contemporary desire for complete independence of Norway from Sweden, and referred to the many Norwegians who had migrated to a better life in the US.

Probably painted in the same year, Krohg’s 17th of May 1893 was an even bolder statement about Norway’s nationhood. The seventeenth of May had been increasingly celebrated as Constitution Day since the signing of the national constitution in 1814. Not only is this painting full of Norwegian people, but the Norwegian flag shown lacks the ‘herring salad’ badge marking the union of Norway with Sweden, a clear indication of his feelings about independence.

From the autumn of 1893, Krohg was away from home almost constantly. He first went to Copenhagen, then on to Berlin and Paris. He stayed in Skagen for his last summer there in 1894 before returning to Oslo.

In 1895, he painted one of his more enigmatic works, a throwback to his social narratives, and something of a ‘problem picture’: Eyewitnesses. It’s nighttime in a living room. Two fishermen stand in front of a door, still wearing their soaked and soiled oilskins, and appear to have entered the room straight after coming ashore from the sea. One stares in shock towards the viewer, the other looks down and away. Both appear full of unease, silent and immobile.

At the right, a young woman is standing, leaning forward towards the men, as if listening to them. She looks anxious, with her hands clasped in front of her chest. Behind her an oil lamp burns brightly, there are the leaves of a large potted plant, and a couple of paintings on the wall behind a large blue settee.

One possible reading is that the men have brought news of the loss at sea of the woman’s husband, an event of which they were eyewitnesses.

In the coming years Krohg was to return to the sea in his paintings.

References

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

If you bought an M1 Mac with just a 256 GB internal SSD and have kept up with macOS upgrades and updates, should you be worried that it’s running out of space by the time it makes it to Tahoe? Dare you look at Storage settings to see how much of the SSD is now swallowed up by System Data? This article explains why macOS 26 shouldn’t devour the last of your SSD, and how you can ensure that it doesn’t.

What’s on your Mac’s internal SSD?

Internal boot disk layout is most complex in Apple silicon Macs, as theirs is divided into three partitions (or APFS containers). Two are hidden and contain pre-boot and other low-level support files, and amount to around 6 GB. The Macintosh HD partition then takes the lion’s share, the whole of the remainder. Even on a 256 GB SSD, that’s about 250 GB.

Volumes within Macintosh HD include:

• System, just over 12 GB,
• VM, varies in size according to how much virtual memory is swapped out to disk,
• Preboot, just under 8 GB,
• Recovery and others not normally mounted, a total of less than 2 GB,
• Data, whose size is determined by what you store there.

The system your Mac actually boots into isn’t the System volume itself, but a snapshot made of it, occupying the same space, plus a little extra for the snapshot’s metadata including its tree of hashes to form its seal and signature. Because this is a snapshot it uses the same data stored for the System volume, and doesn’t double that up.

This should allow your Data volume a maximum of 228 GB, less any space required by the VM volume. Although installation of a macOS upgrade or update will require substantial additional space, once that’s complete the space taken by the System volume and its snapshot should fall to little more than 12 GB.

What happens when macOS is upgraded?

In traditional macOS upgrades, the Installer app was downloaded first, and itself required around 13-15 GB. That was run, and expanded its contents to be installed onto the System volume, replacing much or all of it.

Updates work more economically, as they contain only the files that have changed, so far less than the Installer app. When they’re installed, they replace only those files changed in the System volume, ready for a new snapshot to be made from that, to be used to boot that Mac. So an update-style upgrade, as you should get when going from macOS 15.7 to 26.0, should require a much smaller download, a faster install, and less space to install the new version of macOS. However, the end result should be identical, with exactly the same files installed in the System volume, and exactly the same in the snapshot used when running.

Whichever is used, the installation process is similar. First, the files to be installed are expanded, then they’re written to the mounted System volume, with some going onto the Data volume as well. Once the System volume is complete, a snapshot is made of it, and that’s sealed using a tree hierarchy of hashes, culminating at the top of the tree in the seal.

What is System Data?

Storage settings scans the contents of the boot volume group, Macintosh HD, and divides the storage used into different categories like Applications and Podcasts. It appears to total those up and account for the remainder of storage used in the category System Data. That doesn’t include the size of the System volume, or its snapshot, but can include temporary files like caches, snapshots, and anything else it can’t account for in other categories.

Taking control

If there are substantial amounts of space that aren’t accounted for on your Mac’s internal SSD, and you want to reduce that, you need to account for it before deciding what to do about it.

First check for large snapshots. I hear repeatedly of Macs that turn out to have hundreds of GB being used by snapshots unnecessarily, and the current record is over 400 GB. The easiest place to check for those is in Disk Utility. In the sidebar on the left select the Data volume, then Show APFS Snapshots in the View menu for them to be displayed at the foot of the main view.

Backup utilities including Time Machine normally make a snapshot with each backup, and retain them for 24 hours, following which they’re automatically deleted. As snapshots can’t exclude folders in the way that Time Machine can in its backups, if you’ve been working with a couple of 100 GB VMs then they will be retained in snapshots even though you probably exclude them from being backed up.

Once you’re happy that free space isn’t being retained in snapshots, use a disk mapping utility like DaisyDisk or GrandPerspective to hunt down other large files and folders that you may not need. One reader here recently discovered that their iOS and iPadOS backups had taken over more than half the space on their Mac’s SSD.

Wait a day or two after upgrading

Installing a macOS upgrade also changes files on your Data volume, and may retain temporary support files. These are normally cleaned up in the next 24 hours, and you may be able to encourage that by starting your Mac up in Safe mode, leaving it a couple of minutes, then restarting it in normal user mode.

By a couple of days after the upgrade, your Mac should have returned to normal use of storage. If it hasn’t, check snapshots and go hunt that missing space.

Apple has released its weekly update to XProtect, bringing it to version 5317. As usual, it doesn’t release information about what security issues this update might add or change.

This version adds five new detection signatures to its Yara file. These include another newcomer with four signatures, MACOS.DAILYDUMPLING, and MACOS.SOMA.SEEND to add to the large Amos/Soma family.

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_15-5317

I apologise for the late announcement of this update, which seems to have been released after 22:00 GMT on 30 September, but was still incomplete here through the whole of today, 1 October.

Sequoia and Tahoe systems only

This update has already 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 5317 but your Mac still reports an older version is installed, you should be able to force the update using
sudo xprotect update

Before the Dutch Golden Age, paintings of everyday life, now widely termed genre paintings, were seldom seen. That changed in the Dutch Republic, when they became among the most popular, if not the majority. Several of the best known artists of this period specialised in them, among them Gerard ter Borch (1617–1681) who made himself something of an international career as a result.

Ter Borch was born in the city of Zwolle, well to the east of Amsterdam. As his father was also an artist with the same name, he’s sometimes distinguished as Gerard ter Borch the Younger. He had already started to travel in 1632, when he was training in Amsterdam, and for the next twenty years or so he painted in England, Germany, France, Spain and Italy.

For the thirty years between 1618-1648, central Europe had been engulfed in a bitter war between the Habsburg states, including the Holy Roman Empire and Spain, and their enemies, including the Dutch Republic. Ter Borch’s magnificent painting of The Ratification of the Treaty of Münster, 15 May 1648 (1648) recorded the moment that the Thirty Years War ended, with the ratification of this treaty between the Dutch Republic and Spain. It also marked the birth of the Dutch Republic as an independent country.

The artist even seized the opportunity to include himself among the ranks of dignitaries: he is at the far left, with long hair and looking directly at the viewer. Although this may look a large and grand work, ter Borch painted it on copper, and it is little larger than a miniature.

But most of his surviving works are portraits and interior scenes of everyday life.

The Messenger, popularly know as Unwelcome News, from 1653, develops what came to be one of his favourite themes. The young man at the left is still booted and spurred from riding to deliver a message to this couple. Slung over his shoulder is a trumpet, to announce his arrival and importance. The recipient wears a shiny breastplate and riding boots, and is taken aback at the news. His wife leans on her husband’s thigh, her face looking serious.

The scene is the front room of a house in the Golden Age. Behind them is a traditional bed (typical in living areas at the time), with some of their possessions resting on a table between the couple and their bed. Hanging up on a bedpost is the husband’s sword, and behind them is a gun and powder horn. Is the letter news of his recall to military service, perhaps? Will he soon have to ride away from his wife, leaving her to bring up their family?

At about the same time, ter Borch painted A Maid Milking a Cow in a Barn (c 1652-54), incorporating its own still life of everyday farming objects including a winnowing sieve and an axe.

Mother Combing the Hair of Her Child (c 1652-53) shows a regular domestic routine, expressed more bluntly in its alternative title of Hunting for Lice. The mother is looking intently at her young daughter’s hair for traces of lice and nits, and running a fine-tooth comb through it to remove any.

Three Figures Conversing in an Interior (c 1653-55) is another of his narrative genre works, and more popularly known as Paternal Admonition. Standing with her back to us, wearing a plush going-out dress, is the daughter. To her left is a table, on which there is a small reading stand with books, almost certainly including a Bible. Her parents are young, and they too are fashionably dressed. Her mother appears to be drinking from a glass, but her father is at the very least cautioning his daughter, if not giving her a thorough dressing-down. He wears a sword at his side. Behind them is a large bed, and to the right the family dog looks on from the gloom.

Ter Borch’s half-sister Gesina, herself a painter, appears to have been his model for Woman Writing a Letter (c 1655), which makes obvious his connection with Vermeer. Move this woman to a desk lit through windows at the left, light her surroundings, and you have a painting very similar to some of Vermeer’s. This painting shows a heavy decorated table cover pushed back to make room for the quill, inkpot, and letter. Behind the woman is her bed, surrounded by heavy drapery, and at the lower right is the brilliant red flash of the seat.

The Spinner is dated to about 1655, but may well have been the pendant to Mother Combing the Hair of Her Child (c 1652-53), and uses the same model. Here she looks intently at her work, a small dog on her lap.

Long before its value in preventing scurvy was realised in 1747, or it was carbonated even later, still cloudy lemonade had become a popular soft drink. Extensive trade links of the Dutch Republic made this drink available to the middle classes, as celebrated in ter Borch’s The Glass of Lemonade (1655-60).

A fashionably-dressed young man is helping to prepare a glass of lemonade for a young woman, who is equally open about her love of fashionable clothing. Behind her is the woman’s nurse or maid, who is having to comfort her through the excitement of the experience. They’re surrounded by a contemporary Dutch interior, with the inevitable bed lurking in the dark at the right, a small but heavily-built wooden table to the right, and a lighter-weight table at the lower left.

The Letter from about 1660-62 returns to his favourite theme of the reading and writing of letters. Two young women are working together, apparently to write a reply to the letter which is being read by the woman on the right. A boy, perhaps their younger brother, has just brought in a tray bearing an ornate pitcher of drink. In front, a small dog is curled up asleep on a stool.

Ter Borch’s backgrounds become lighter in his later work, as shown in The Music Lesson from about 1668. A teacher stands over a young woman, who is learning to play the lute. By this time, the basic lute had become extended to accommodate additional strings for a wider register. This is often referred to as a theorbo, although in modern terminology it’s probably more of an archlute, and seems to have been fashionable in the Dutch Republic at this time. Resting on the table is a cello, and asleep on a chair is a small dog. Note that the room still contains a bed in the background.

Just as mothers had to check their children for parasites in the hair, so pet owners had to remove fleas from their pets. Ter Borch’s late painting of A Boy with his Dog, also known as The Flea-Catcher (after 1666), shows this, in fairly barren surroundings.

As promised earlier this week, I’m delighted to offer a new version of my log browser LogUI that provides a Diagnostics Tool to help you understand log folders and discover any problems with them.

Open its window using the Diagnostics Tool command in the Window menu, and you’re offered four tools at the top.

The first, Get Info, performs a simple analysis on the files in the selected diagnostics folder. By default, that’s your current live log, in the path /private/var/db/diagnostics, in your Data volume. After telling you how many log files there are in each of its three main folders, and the number of timesync files, it reports the date and time of the oldest Persist log file, marking the start of the continuous log record, in this case nearly 4 days ago.

You can use these tools on any diagnostics folder you can access through its dialog. This includes Time Machine backups, external boot disks, and other bootable systems. Don’t click on the Open button, though, until you’ve selected the diagnostics folder in the view above.

Locating the diagnostics folder in a Time Machine backup can be interesting, but once you’ve found it, LogUI will happily check it for you.

The Catalogue tool lists all the tracev3 log files in the folders inside diagnostics, starting with those in Persist. It gives each file’s creation and modification timestamps, indicating the range for log entries within them, their size in bytes, and an estimate of the period that file covers.

The Analyse tool extracts information from each of logd‘s statistics files, with the number of log entries broken down in frequency order. If you tick the CSV checkbox, they will be delivered in CSV format, ready to import into other software such as a spreadsheet.

The last of the tools, Save Text, saves the contents of the window to a text file for your records.

Further information about locations used for log files is in this article.

LogUI 1.0 build 74 is now available from here: logui174
from Downloads above, and from its Product Page.

Enjoy!

If you’ve left plates coated with egg for a while, you’ll know how difficult its residue can be to remove. No one knows when people first took advantage of this in paints, but earliest surviving examples date from late classical times. By the Renaissance, egg yolk was popular as a binder in artists’ paints, and the technique of egg tempera was used to create many of the masterpieces of the day.

Pure egg tempera technique uses the proteins, fats and other constituents of the yolk of fresh hens’ eggs as its binder; being water-based, water is its diluent. Applied thinly to an absorbent ground such as powdered chalk in a gesso, this quickly sets to form a hard if not brittle paint layer which, unlike glue tempera, can’t readily be removed by water.

Because egg tempera forms such a hard paint layer but is applied thinly, it’s prone to cracking unless the support is rigid and doesn’t change dimensions over time. Early egg tempera paintings were almost exclusively made on wood, but more recently stretched canvas has been used instead. That can lead to cracks and eventual mechanical failure of the paint layer. Egg tempera on wood panel was the favoured combination for easel paintings during the early Renaissance, particularly in Italy.

The finest paintings in egg tempera use only fresh eggs; as eggs age, particularly when they’re not refrigerated, separating the yolk becomes more difficult, and the resulting paint layer doesn’t appear as strong.

Since the nineteenth century, some paint manufacturers such as Sennelier have offered tubed paints with egg as their main binder, but with the addition of some drying oil to form an egg-oil emulsion. These have some of the properties of pure egg tempera, but are more versatile in their handling, and can be used like gouache and even, to a degree, like oil paints. These appear to have been derived from recipes recorded during the Renaissance.

Earliest European examples of egg tempera, such as Margarito d’Arezzo’s The Virgin and Child Enthroned, with Scenes of the Nativity and the Lives of the Saints from the middle of the thirteenth century, often incorporate extensive gilding and today might appear ‘primitive’.

Even the earliest paintings in egg tempera can be remarkably well preserved, such as Duccio’s Healing of the Man born Blind from the early fourteenth century. Although it only forms a thin paint layer, egg yolk is sufficient to preserve high levels of chroma in the pigments.

As the modelling of flesh and clothing became more realistic, egg tempera proved more than sufficient for the task.

One of the finest early works painted entirely in egg tempera is the anonymous Wilton Diptych in London’s National Gallery. Thought to have been made in France at the end of the fourteenth century, its exquisite detail would have been painted in multiple thin layers using fine brushes, much like miniatures painted on vellum.

But it was in Italy that painting in egg tempera reached its apogee, with masters like Masaccio, in his Santa Maria Maggiore Altarpiece from about 1428-29 (above) and Piero della Francesca’s Baptism of Christ (below) of a decade later.

During the fifteenth century, egg tempera was progressively replaced by oils in Italy, as it had been earlier in the Northern Renaissance.

Uccello’s large panel of the Battle of San Romano incorporated some drying oils, including walnut and linseed, although it was still fundamentally painted in egg tempera.

By the end of the fifteenth century, many studios had changed to oils. Among the last large egg tempera paintings are Botticelli’s Primavera (above) and The Birth of Venus (below), from the 1480s. The craft labour involved in producing these large works must have been enormous. Although Primavera was painted on a panel, Venus is on canvas, making it more manageable given its size of nearly 2 x 3 metres (79 x 118 inches).

In the closing years of the fifteenth century, Michelangelo kept to the hallowed tradition of egg tempera on wood in this unfinished painting of the Virgin and Child known now as The Manchester Madonna. This shows how he painstakingly completed each of the figures before moving onto the next, and the characteristic green earth ground.

By this time, the only common use for egg tempera was in the underpainting before applying oils on top. This remains a controversial practice: performed on top of gesso ground it can be successful, but increasingly studios transferred to oils. Egg tempera didn’t completely disappear, though. With so many fine examples of how good its paintings both look and age, there were always some artists who have chosen it over oils.

Some nineteenth century movements that aimed to return to the more wonderful art of the past experimented again with egg tempera. In the late 1870s, John Roddam Spencer Stanhope started to use the medium, and made one of his finest works, Love and the Maiden (1877), using it.

A later exponent who was rigorous in his technique was Adrian Stokes, who used it to great effect in this landscape of Autumn in the Mountains in 1903.

But for my taste, the greatest painter in egg tempera since the Renaissance has to be one of the major artists of the twentieth century: Andrew Wyeth (1917–2009). As his works remain in copyright, I recommend that you browse his official site, where you can see just how effective egg tempera can be in the hands of a great master. It may not be as popular as in the past, but egg tempera still has a great deal to offer.

One seemingly widespread complaint about recent versions of macOS has been slow launch times of notarized apps even after they have cleared quarantine in their first run. Debate on the cause of this was vigorous in April and May, but was overtaken by Apple’s announcement of macOS 26 Tahoe. I therefore postponed further work on app launch and Gatekeeper until after Tahoe’s release.

This proved worthwhile, as soon after the first beta-release, it was suggested that Tahoe would accelerate the first launch of notarized apps by exempting them from a malware scan, although I have been unable to confirm that from Apple’s published information. That would make good sense: if an app’s CDHashes verify and match those of its notarization ticket, and no known malware was found when it was notarized, then it’s not plausible for it to contain malicious content since notarization was performed. This article considers what has changed in Gatekeeper in macOS 26.0.

Although Apple hasn’t yet updated it for macOS 26, its Platform Security Guide explains what Gatekeeper does in macOS Sequoia. For an app, plug-in or an installer package downloaded from outside the App Store and opened on a Mac, Gatekeeper verifies the software:

• is from an identified developer, in signature checks;
• is notarised by Apple to be free of known malicious content, in notarization ticket checks;
• hasn’t been altered, in CDHash verification;
• doesn’t contain known malicious content the first time it’s opened, regardless of how it arrived on the Mac, in a first run XProtect scan.

To assess this, I have used Calibre version 8.11.0 installed in a macOS virtual machine running on a Mac mini M4 Pro. Calibre is a large app at just over 1 GB with many components to be checked. This version has 82 items in its Frameworks folder, 20 executables in its MacOS folder, and 25 dylibs in its Plugins folder, totalling 113 dylibs and others that need to be checked.

Two VMs were prepared, one with macOS 15.7 Sequoia installed, the other with macOS 26.0 Tahoe. Both were run with 5 CPU cores, 16 GB memory, 100 GB disk, and bridged networking.

Calibre was launched three times in Tahoe, first when freshly installed and still in quarantine. Following that, the VM was shut down, started up 4 hours later and Calibre was run a second time. The VM was shut down again, and started up two days later for a third run. Log extracts were collected within a minute using LogUI.

Tahoe: First run in quarantine

This proceeded similarly to first run in Sequoia, with the exception of XProtect malware scanning. Soon after com.apple.syspolicy.exec reported that a GK (Gatekeeper) process assessment was starting, it wrote the log entry
Skipping up front XProtect scan on: PST: (path: f0970f7f0ab1ff9f), (team: NTY7FVCEKP), (id: (null)), (bundle_id: (null))
That was reiterated later, shortly before the outcome of the GK evaluation
Skipping XProtect scan on seen software: PST: (path: f0970f7f0ab1ff9f), (team: NTY7FVCEKP), (id: (null)), (bundle_id: (null))
There were no other log entries that suggested an XProtect malware scan had been attempted.

As is normal in the first run, notarization was checked using CloudKit, there was abundant evidence of CDHash verification, the user was prompted for their approval, and once that was complete the code was allowed to proceed.

Despite the lack of an XProtect scan, launch was as long as previous first runs in recent versions of macOS, taking 10.4 seconds from the second click to launch the app, to display of the prompt for user approval. During that period, a standard progress dialog was displayed. Entries in the log consisted of about 13,000 messages of SecKeyVerifySignature from syspolicyd and trustd, with repeated errors of
SecError com.apple.securityd Malformed anchor records, not an array

Tahoe: Subsequent runs

The second and third runs, out of quarantine, were almost identical in the log, and similar to those in macOS 15.7 (below). com.apple.syspolicy.exec announced early that the code had already been evaluated, and those previous results would be used. Provenance data was found, and the evaluation completed without any CloudKit check of notarization. Times from the second click to launch the app, to loading of the app’s preferences were 0.64 and 0.66 seconds.

At various times, the kernel reported that it was considering a malware scan on one of the executables being checked, for example
ASP: considering malware scan (activeRulesVersion: 11716915239283693719 lastScanVersion: 0 chgtime: 1758884893 lastFileScanTime: 1758884893 threshold: 1758884893 pid: 949 info_path: /Applications/calibre.app/Contents/MacOS/calibre proc_path: /Applications/calibre.app/Contents/MacOS/calibre isNewerThanScan: 0 needsVersionScan: 0 is_time_eval_exempt: 0 is_scan_version_exempt: 1
Those appear new to macOS 26, and haven’t been seen in any log records from macOS 15.7 or earlier. Executables cited in those messages extended beyond components of Calibre to others that happened to be running at the time, but none was followed by any report of whether a scan was performed as a result.

Although they didn’t delay app launch, at the same time amfid entered the path of the main executable and 112 dylibs and others to check each individually. For the dylibs and others, each was accompanied by a report from the kernel of
AMFI: constraint violation [dylib path] has entitlements but is not a main binary
Those took a period of approximately 3 seconds in each of the two runs.

Sequoia: 2nd and 3rd runs

These were remarkably similar, and in many parts identical, to those in Tahoe, except that there were no messages reporting consideration of malware scans. Times from the second click to launch the app, to loading of the app’s preferences were slightly quicker than Tahoe, at 0.59 and 0.59 seconds. Concurrent time to iterate through all the executable components was also shorter at 2.6 seconds, with identical reports of constraint violations.

Conclusions

• macOS 26.0 Tahoe does now skip reported XProtect malware scans when a notarized app is run for the first time, when in quarantine.
• Despite that, first run checks undertaken in Tahoe can still take significantly longer than in subsequent runs.
• This is the result of a vast number of SecKeyVerifySignature entries written during checks on executables.
• Tahoe also considers explicitly whether to perform malware scans on other processes being run, although none were undertaken. These are new in Tahoe.

From this evidence, I’m not convinced of any significant improvement in launch times. Please let me know whether you think that Tahoe has improved the speed of your app launches.

Previous articles:
Why some apps launch very slowly
Gone to launch

Apple has just released macOS 26.0.1 Tahoe, which fixes the problem upgrading to 26.0 on Mac Studio M3 Ultra models, and apparently fixes other urgent bugs.

For Apple silicon, the update is a 1.76 GB download.

Tahoe 26.0.1 fixes a single vulnerability, although Apple doesn’t report that it’s already being exploited. The same is also fixed in Sequoia 15.7.1, and in Sonoma 14.8.1.

macOS 26.0.1 has build number of 25A362, Safari version 26.0.1 (21622.1.22.11.15), and a Darwin Kernel version of 25.0.0. There has been no change in iBoot firmware, which remains at 13822.1.2.

As Apple hasn’t been forthcoming about what else has changed, here’s my list:

• Passwords app has gone from version 2.0 to 2.0.1, suggesting it has at least one significant bug fixed.
• AppKit framework has had an increment in build number, also suggesting bug fixes.
• CoreText framework likewise, with bug fixes for a higher build number, possibly related to the fixed vulnerability in font handling.
• Security framework has a substantial increase in build number, implying bug fixes there as well.

Otherwise, remarkably little has changed.

Updated 1910 29 September 2025.

In their descent into the depths of Hell, Virgil and Dante have just entered circle eight for those who committed fraud in its broadest sense. This consists of what Dante refers to as malebolge, best translated as rottenpockets, a series of ten deep trenches each of which caters for a different type of fraud. Dante compares these to the defensive earthworks surrounding the outer walls of castles of the day.

Virgil leads Dante into the first of these rottenpockets, where souls are being lashed by demons to keep them moving constantly. These are pimps and seducers, among whom is a Bolognese man, a Guelph, who pimped his sister, the beautiful Ghisolabella, for political gain.

The pair move on past other sinners being scourged, where they see Jason, who seduced then abandoned the young Hypsipyle, queen of Lemnos, and later did the same with Medea. They then enter the second rottenpocket, for flatterers, who are wallowing in excrement.

They find a contemporary figure from Lucca, and see Thaïs, a Greek courtesan who notoriously flattered her partners. She is now covered in filth and thoroughly crabby.

In the third rottenpocket, Dante and Virgil come across corrupt religious leaders or Simonists, who sold church privileges, and are trapped headfirst in rock holes, their protruding feet being roasted with flames. The key figure here is Pope Nicholas III, who at first confuses Dante with Pope Boniface VIII, who is also in the same rottenpocket. Pope Nicholas was known for his nepotism, which included appointing three of his own family as cardinals.

Virgil carries Dante on to the fourth rottenpocket, reserved for soothsayers. Their heads are turned to face backwards, so that the tears streaming from their eyes wet their buttocks.

Virgil identifies several of them from classical times, including the Theban Tiresias; Dante recounts how he became a soothsayer after he had twice changed gender, as told by Ovid in his Metamorphoses. The list concludes with three near-contemporaries: Michael Scot, a scholar and astrologer to Emperor Frederick II, and two well-known Italians.

The fifth rottenpocket they find to be filled with corrupt public officials, or barrators, who sold public appointments and are immersed in a sea of boiling pitch, while being further tormented by a pack of vicious devils known as malebranche, ‘evil-claws’.

The latter are armed with long hooks, which they use to push the souls down into the pitch, much as you might push down lumps of meat that rise to the surface of a stew. Those devils are so evil as to threaten Dante, so Virgil whisks him on to the next rottenpocket for hypocrites.

Any resemblance to real persons, living or dead, is not only intentional, but of their own making.

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

Giotto di Bondone (c 1267–1337) was one of the great masters who bridged between the late Middle Ages and the early Renaissance. He was born near Florence, and is reputed from about 1296 to have painted a cycle of frescoes in the Basilica di San Francesco d’Assisi, in Assisi. This is hotly disputed though, and those may have been painted by Cimabue instead. The scene of The Devotion of the Devils from Arezzo shows what may, directly or indirectly, have been an inspiration to Dante, although I don’t know whether there is any evidence that the poet ever visited Assisi.

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 327. Here are my solutions to them.

1: Lost rocket platform as an app for your apps.

Click for a solution

Launchpad

Lost (it has been removed from Tahoe) rocket platform (a launchpad) as an app for your apps (what it was, an app for launching other apps).

2: Burning telegraph and lynx now disconnected.

Click for a solution

FireWire

Burning (fire) telegraph (wire) and lynx (Texas Instruments’ name for FireWire, IEEE 1394) now disconnected (support has been dropped from Tahoe, although oddly its kernel extensions are still present).

3: Happy Christmas 2017 is sad September 2025 for the most powerful Mac.

Click for a solution

iMac Pro

Happy Christmas 2017 (although announced the previous June, it shipped in December 2017) is sad September 2025 (it’s one of the T2 models dropped from Tahoe) for the most powerful Mac (when introduced, it was described as “the most powerful Mac ever made”, at least until the Mac Pro 2019).

The common factor

Click for a solution

They have all been dropped from Tahoe.

I look forward to your putting alternative cases.

By far the most common problem experienced with the Unified log isn’t its large number of entries, but a lack of entries. You go to check your Mac’s security using SilentKnight, or Skint runs its automatic daily check, and they can’t find any log entries recording XProtect Remediator scans. Since those are obtained by analysing the log for the previous 36 hours, when your Mac’s logs only go back 8-12 hours, entries for the last set of scans are likely to be missing. This article looks at why that happens, and how macOS maintains its log.

Traditional Unix-style logs are maintained according to their age. Every 24 hours, routine housekeeping procedures delete log files over a certain age, typically five days, in the process of rolling the log. Because the Unified log could over that five-day period have swallowed many GB of storage, its maintenance service logd deletes log records according to multiple criteria including the space they occupy, their age, and the type of entry. This is considerably more complex, and occurs in three phases, according to where the entry is stored.

Ephemeral entries

Log entries are initially written to memory, before logd writes most of them to permanent storage on disk.

The first substantial purging of entries thus occurs when logd decides which are ephemeral and won’t be written to disk. This can be seen by following the number of entries in a short period of high activity in the log, over time, and is shown in the chart below for a sample period of 3 seconds.

When fetched from the log within a minute of the entries being written, a total of 22,783 entries were recovered. Five minutes later there were only 82% (18,655) of those remaining. Attrition of entries then continued more slowly, leaving 80% (18,309) after 8 hours. Analysis suggests that over this period in which there were about 6,100 log entries per second written to disk, approximately 1,700 log entries per second were only kept in memory and never written to disk. That suggests about 22% were ephemeral, a proportion that’s likely to vary according to the origin and nature of log entries.

Persist entries

The great majority of log entries that survive to be written to permanent storage are kept in the tracev3 files in /private/var/db/diagnostics/Persist, where logd maintains them according to the total size of that folder, with a target of 520-530 MB. As each tracev3 file is up to 10.5 MB in size, that results in logd retaining about 50 files in that folder, although some are smaller than the maximum.

Two of my apps currently provide the datestamp of the start of the current collection of Persist log files as an indicator of the oldest log entry available from them: XProCheck, and Mints with its Logs button. This is a feature I intend adding shortly to LogUI.

However, not all log entries are stored in those Persist files. Looking back in time at total log entries available for a set ten minute period each day, you might see totals like:

• 1 day old 33,827 in 10 minutes
• 2 days old 98,534
• 3 days old 59,296
• 4 days old 10
• 5 days old 1
• 6 days old 40
• 7 days old 0
• 8 days old 358
• 9 days old 1.

Those for the last 3 days are almost all Persist entries, but older entries are those retained in tracev3 files in the Special folder.

Special entries

Fault and Error log entries are normally written to the tracev3 files in the Special folder, and may contain additional message content kept in the warren of folders and files inside /private/var/db/uuidtext. logd purges entries from Special files separately, and apparently on the basis of their type and content rather than size. As a result, the Special folder can contain many tracev3 files of sizes ranging from over 2 MB to just a few KB, with their size tending to reduce with age. Any log entries recovered from dates before the oldest Persist file thus must have come from Special files.

Although files stored in the uuidtext folder are small, there can be a great many of them, and total size of that folder can exceed 1 GB. Those too are maintained by logd.

Other folders and files

tracev3 files stored in the Signpost folder contain only Signpost log entries used for performance assessment, and are purged at a slower rate than Persist files, but not retained as long as Special files. The High Volume folder appears seldom if ever used. The timesync folder contains time synchronisation data, small files that normally cover the whole period of Special files.

The /private/var/db/diagnostics folder contains several other files, including the logs of logd and logd_helper, and most significantly pairs of statistical summaries written during log maintenance, named logdata.statistics.[n] where n is a number starting from 0, in both .txt and .jsonl (JSON) format.

Each time logd performs maintenance on a tracev3 file, or on associated uuidtext files, it records data about the files in the current logdata.statistics files, both as plain text and in JSON format. The most useful of these records occurs when a Persist tracev3 file is rotated from being the file into which new log entries are written, to being retained without further additions. That entry records:

• the name of the tracev3 file;
• the time of rotation, thus the time immediately following the last log entry to be made to that file;
• the total number of log entries in that file, for example 42,365,476;
• for the top 20 processes that wrote entries in that period, the number of entries, the percentage of total entries, and the path to the process, listed in order of number of entries.

For example, in that tracev3 file containing a total of 42,365,476 entries, the kernel might have written 13,095,296 entries, 30.9%, and be top of the list, while runningboardd might only have written 1,223,157 or 2.9%. These statistics can be valuable in drawing attention to periods when there were problems, and for discovering which entries are limiting the coverage of Persist files, making it impossible for apps to recover entries for XProtect Remediator scans, for example.

Statistics entries for memory rollovers can also be useful, as are those for Special file rotation, although the latter contain fewer entries than Persist files.

Extending the period of log coverage

Currently, there doesn’t appear to be any way to set logd‘s size allowance for Persist files. When the Unified log was first introduced, it wasn’t unusual for that setting to preserve full log records covering a period of up to 20 days. As more processes now write copious entries in the log, a Mac that’s left awake and running at all times may only retain the last 20 hours of Persist entries, or even less.

Macs that don’t need to be awake and running at all times can extend their log coverage by sleeping or being shut down, when of course no entries can be written. If that isn’t possible, you can write your own XML property lists to /Library/Preferences/Logging to limit the retention of specific categories of entry. However, experience shows that only achieves small extensions to time coverage. It’s also worth bearing in mind that disabling privacy protection in the log will increase the size taken by most log entries, so shortening time covered by the retained logs.

Perhaps the wisest and most effective way to extend the time coverage of logs is to discover the causes of excess entries and address those, although that’s inevitably the most difficult solution.

One little-used technique is to turn log records in backups into logarchives, enabling old log entries to be accessed days or even years after they have been written. As an example of what can be achieved, the log entries below were written eight years ago, on 26 September 2017, saved in a logarchive, and browsed using LogUI on 26 September 2025.

I will explain how to do this in a future article in this series.

Summary

• Log maintenance is a sophisticated managed process that discards log messages for several reasons, most generally to keep total log file size within limits, rather than removing entries purely on the basis of age.
• A fifth of log entries are likely to be ephemeral, and lost from the log within the first minutes after they’re written. If you want the fullest entries possible, obtain the log excerpt as soon as possible after its entries have been written.
• Most retained log entries are written in Persist logs, where tracev3 files are removed by age to keep their total size to just over 500 MB. Those should preserve log entries for hours or days after they’re written.
• Entries for Faults and Errors are stored in Special logs, where they’re kept for longer, sometimes for weeks.
• logdata.statistics files provide detailed statistics for log files as they’re rotated, and can tell you which processes wrote most entries.
• As logs aren’t written during sleep, or when shut down, allowing sleep and shutting down will extend the duration of log records.
• Time Machine and other backups can be used to recover old logs as logarchives.

This weekend we’re visiting what used to be a small village on the bank of the River Oise, where several of the French Impressionists developed their skills in painting landscapes en plein air. In yesterday’s first article we had reached 1876, the year of the second Impressionist Exhibition in Paris.

In complete contrast to his few landscapes influenced by Paul Cézanne, in 1876 Pissarro also painted some views of the commercial barges trading on the River Oise, including this of Barges at Pontoise, the only canvas in which the boats dominate his composition. This painting remained unsold at the time of the artist’s death, and wasn’t even exhibited until 1936.

The Oise near Pontoise in Grey Weather is another of Pissarro’s views of the River Oise from 1876.

The Rainbow, Pontoise, which Pissarro painted in 1877, was shown at the Third Impressionist Exhibition that year. It’s a panoramic view of the fields around the neighbouring area of Épluches viewed from Pontoise, with a modest and realistic rainbow.

Around 1877, when Pissarro was probably in company with Paul Cézanne at Pontoise, the pair of them painted the same motif hidden or revealed by the same trees. Pissarro’s version of Côte des Bœufs, Pontoise, above, is the more famous, and captures texture in everything, from the smoother surface of the track to the smaller branches, and presents an essay on the form and structure of trunks and branches.

Cézanne’s La Côte Saint-Denis à Pontoise shows little or no anatomical basis to the construction of his trees, whose branches are only loosely related to foliage. He simplifies throughout, with little or no texture, and more basic shadows, on the trunks, and the foliage is depicted as amorphous areas of leaf colour.

Béliard’s Moulin de Chauffour, Effect of Snow (1878) is another winter scene from the area near Pontoise, and is significantly less painterly than Pissarro or Cézanne.

By 1880, when Pissarro painted this Landscape at Le Valhermeil, Auvers-sur-Oise, his work was losing its conventional Impressionist facture, as he adopted smaller, staccato brushstrokes and his style became more ‘pointillist’.

Pissarro also started to transfer his attention from the land to its inhabitants, here the rural poor of these Cottages at Le Valhermeil, Auvers-sur-Oise (1880).

Pissarro’s Peasant Woman Digging, the Jardin de Maubuisson, Pontoise (1881) shows two women working in the vegetable garden of this large house in the village. This painting was first shown at the seventh Impressionist Exhibition the following year.

The Harvest, Pontoise, from 1881, is one of several of Pissarro’s paintings focussing more closely on agricultural activities, and now becoming overtly ‘pointillist’. Because of the brushwork involved, he couldn’t have painted this in front of the motif, and it turns out to be a second copy of an earlier and apparently identical painting.

This increasingly human content, in paintings such as his Peasant Woman and Child Returning from the Fields, Auvers-sur-Oise from 1881, drew comparisons with Millet, from whom Pissarro sought to distance himself in terms of modernity. This painting was bought by Durand-Ruel later that year, and shown at the seventh Impressionist Exhibition.

Pissarro later concentrated his attention on Éragny, then cityscapes of Paris. Cézanne returned to his family home in Aix-en-Provence, and Béliard became the mayor of Étampes further south. Today Pontoise is part of the ‘new town’ of Cergy-Pontoise, and its population has grown to well over 30,000, within an urban area of nearly a quarter of a million.

Last week’s outstanding news was the discovery of a potential treatment for Huntington’s disease, that killed Woodie Guthrie at the age of 55, a tragedy I learned of from his son Arlo’s movie Alice’s Restaurant (1969).

That treatment is so complex that even James Gallagher’s diagrammatic account doesn’t do it justice, but it provides a much clearer picture than some of the treatment offered for our Macs. Although in a different league, our novel treatment of the week is Device Recovery Assistant, as I showed here on Friday. It’s sufficiently new that Apple hasn’t quite gone firm on what to call it. Its sole account refers to it as Recovery Assistant, in accordance with the menu command used to open the app in Recovery mode. But when it’s running, it claims to be Device Recovery Assistant, which sounds like it might also be good for your iPhone or iPad, but isn’t. That’s a similar feature added to iOS and iPadOS 26, as explained here.

I’m still a little wary of magic healing tools in Recovery mode. The first is there even now, waiting to catch those who’ve taken AI a little too seriously, and think running repairHomePermissions might be a good idea. Whatever you do, please don’t try this one at home, as its effects can be devastating. I now only run it in a disposable virtual machine, as reversing its changes would be so time-consuming.

In Recovery mode, typing repairHomePermissions into Terminal launches a GUI app to ‘repair permissions’ in a selected Home folder in the Data volume. Far from repairing them, each time I have tried this it locks me out of every folder in my Home folder and wreaks havoc elsewhere. Yet somehow this historical remnant has been left behind in Recovery mode to catch the unwary.

(Device) Recovery Assistant doesn’t appear to do anything so disastrous, but Apple is completely opaque as to what it actually does. Even its description for macOS 26 beta testing used the same words, “Recovery Assistant is a new way to recover your device if it doesn’t start up normally. It can look for problems and attempt to resolve them if found.”

Just what “issues” can it discover, and how might it attempt to “resolve” them? One thing I can report is that it doesn’t attempt to repair the damage done by repairHomePermissions, and doesn’t see anything wrong with a user not having permissions to access their own folders. Maybe it isn’t that smart yet.

One small clue given by Apple is that it can leave your iCloud connection in need of a further recovery process run when back in normal user mode. Once again, though, information is lacking as to what that does, and why it might be needed.

Of course, if your Mac does have an appropriate problem that prevents it from starting up normally, and it instead puts itself into Recovery Assistant, you have little option but to give it a whirl and hope that it fixes whatever was causing the problem. But why might you want to run Recovery Assistant voluntarily from Recovery mode? Is this something worth doing for specific reasons, or is it just a universal panacea?

With Apple silicon Macs, we’re running out of panaceas. If you don’t know of a specific fix for a problem, most of the old tricks such as resetting NVRAM and SMC, repairing permissions, installing the Combo updater, and re-installing macOS have either become impossible or demonstrably futile. We’re currently left with the innocuous procedure of starting up in Safe mode, and quickly run out of ideas after that.

I’m not suggesting for a moment that Recovery Assistant is a placebo, but until we know more about it, neither can it be a new panacea.

If your Mac starts up in this new Recovery Assistant, or you use it manually in Recovery mode, please let us know what happened and whether it did resolve your problem.

This weekend we travel to what used to be a small village of around six thousand on the bank of the River Oise, to the north-west of Paris. Pontoise was the centre of early Impressionist landscape painting in front of the motif, and appears in hundreds of works painted there from the late 1860s. It’s where Camille Pissarro lived and developed his skills, Paul Cézanne learned to paint en plein air, and others including Vincent van Gogh and Charles Daubigny painted.

The country around Pontoise has also been painted extensively. In these two articles, I include some from Auvers-sur-Oise, a little upstream, but exclude those from Ennery to the south, Éragny down river, where Pissarro settled later, and Osny to the north-west, all names you’ll see in the titles of significant Impressionist paintings.

We start in 1867, in the early days of the development of Impressionism, with Camille Pissarro’s Côte de Jalais, Pontoise. This realist view shows the hill of Les Jalais at l’Hermitage, where Pissarro lived at the time, viewed from the Chemin des Mathurins in Pontoise.

The year after he painted these Apple Trees at Pontoise, the House of Père Gallien (1868), the Pissarro family moved to Louveciennes, also to the north-west of Paris, where they intended to settle down in a large rented house. It was here that Pissarro first got to know Alfred Sisley well, when they painted in company, and alongside Monet and Renoir, all four of them starving and fighting off despair from their lack of sales.

The forgotten Impressionist Édouard Béliard may well have painted Boulevard de Fossés in Pontoise alongside Pissarro, Cézanne and Guillaumin in 1872.

Béliard’s Pontoise, View of the Lock (1872-5) was probably among his paintings shown at the first Impressionist Exhibition in 1874. Its composition is reminiscent of Sisley’s The Canal Saint-Martin, Paris from 1872, and its style is similar to those of Pissarro and Sisley at that time.

Paul Cézanne started learning to paint en plein air alongside Pissarro’s easel in 1873, when he painted this view of the House of Père Lacroix, Auvers-sur-Oise. As with all beginners, he took a long time getting the painting to look right, so different sections of the roof were painted several hours apart, as reflected in the orientation of the shadows here.

This view from Cézanne’s first campaign along the River Oise shows the northern bank near the hamlet of Valhermeil, slightly up-river from Pontoise.

Of all the paintings shown at the first Impressionist Exhibition in Paris in 1874, Cézanne’s The Hanged Man’s House, Auvers-sur-Oise (1874) was among the most successful, as he sold it to the collector Count Doria for three hundred francs.

Béliard’s Pothuis Quay in Pontoise, Effect of Snow from 1875 may have been exhibited at the second Impressionist Exhibition in 1876, and is similar in subject and style to the winter scenes painted around Louveciennes by Pissarro and Sisley from 1870 onwards.

In February 1875, with snow still falling, the Pissarros returned to their house in Pontoise, for Camille to paint there again. Effect of Snow at L’Hermitage, Pontoise (1875) strikes a fine balance between an impression captured in haste, and sufficient detail to make it more than just a passing moment.

That year a few of Pissarro’s paintings appear to have been influenced by Cézanne. Perhaps the best example is The Small Bridge, Pontoise, which could easily be mistaken for one of Cézanne’s views in the woods of northern France.

View of the Côte des Gratte-Coqs, Pontoise from the same year is also less distinctively one of Pissarro’s works.

In 1876, Pissarro painted this large view of one of the gardens in Pontoise: The Garden of Les Mathurins at Pontoise, belonging to the Deraismes Sisters. In fact, the sisters were only renting this large and impressive property, just down the road from where the Pissarros lived, in the Hermitage district of Pontoise. It had formerly been a convent until the French Revolution.