Most urban societies have had some form of police, in addition to soldiers and armed guards. In the Roman Empire these were known as lictors, employed to act as bodyguards to magistrates, who could also arrest suspects and punish offenders under the magistrate’s authority.

Henryk Siemiradzki’s Christian Dirce of 1897 refers to Dirce, a figure in Greek mythology who was killed by being tied to the horns of a bull. Accounts of Roman martyrdoms report that the killing of Christian women sometimes occurred in enactments of the death of Dirce, hence the scene shown here, in which a woman’s near-naked body is draped over the body of a bull. Siemiradzki shows the emperor and his entourage, including two lictors holding their fasces, symbolic rods and axes, gazing at the grim aftermath. The word Fascism is derived from the fasces, which are themselves often symbolic of Fascist groups.

Various police forces evolved across Europe after the Middle Ages, but it wasn’t until the early nineteenth century that they became recognisable in modern form, with organised professionals. Although by no means the first, the city of London’s Metropolitan Police force was created by Act of Parliament in 1829, and quickly became known as Peelers after the minister responsible.

These police forces adopted distinctive dress, typically dark blue, to set them apart from civil guard and other military formations. Most also wore headgear that made them instantly recognisable as officers of the law.

Jules Breton’s first masterpiece, The Gleaners (1854), shows their oversight by the garde champêtre or village policeman, an older man distinguished by his official hat and armband, who was probably an army veteran.

William Powell Frith’s The Railway Station (1862) is set in the crowded and busy Paddington railway station in London that had only been completed a decade earlier by the great Victorian engineer Isambard Kingdom Brunel. The centre of action is at the right of the painting, where an arrest is being made, shown in the detail below. A man dressed in brown clothes is about to board the train, within which a woman stares aghast at the scene. Two Scotland Yard detectives, complete with top hats, are in the process of serving him a warrant for his arrest, the other stood ready with a pair of handcuffs.

Police forces came to the fore later in the century when industrial unrest spread across the coalfields of Europe.

One of the first prominent paintings of a strike is Alfred Philippe Roll’s Miners’ Strike, exhibited in the Salon of 1880 or perhaps the following year. It’s most probably based on a strike at Denain in the Nord-Pas de Calais coalfield of that year. It shows the desperate and increasingly worrying gathering of striking miners and their families. A woman is restraining one man from throwing a rock at the pithead buildings. Mounted police are present, handcuffing one of the strikers.

Police also became involved in the regulation of prostitution in some cities.

Just before Christmas 1886, Christian Krohg’s first novel Albertine was published by a left-wing publisher. Its central theme is prostitution in Norway at the time, and the police quickly seized all the copies they could find, banning it on the grounds of violating the good morals of the people. At the same time as he was writing that novel, Krohg had been working on his largest and most complex painting: Albertine in the Police Doctor’s Waiting Room (1885-87).

In the novel, Albertine starts as a poor seamstress, who is mistaken for a prostitute by the police officer in charge of the section controlling prostitutes. He plies her with alcohol then rapes her. She is summoned to be inspected by the police doctor, whose examination further violates her, making her think that she is destined to be a prostitute, and that is, of course, exactly what happens.

Albertine isn’t the prominent woman in the centre looking directly at the viewer: Krohg’s heroine is the simple and humble country girl at the front of the queue to go into the police doctor for inspection. Behind her is a motley line of women from a wide range of situations. At the right, in the corner of the room, is another country girl with flushed cheeks. Others are apparently more advanced in their careers, and stare at Albertine, whose profiled face is barely visible from behind her headscarf. Barring the way to the surgery door, and in control of the proceedings, is a policeman.

In Denmark, Erik Henningsen’s first major painting bears the enigmatic title of Summum jus, summa injuria. Infanticide (1886). The Latin quotation comes from Cicero’s De Officiis I, 33, and literally means the highest law, the greatest injustice. It is a warning still used that strict application of rights and the law carries the danger of doing some people a huge injustice, and Henningsen’s narrative is an important example of a serious social and legal problem at the time.

Two labourers are digging a small pit at the side of a track across sand dunes. They are supervised by two policemen, one of whom keeps a written record. Behind and to the right is another policeman who holds a young woman by the elbow. She looks down as she is petting a dog.

The subtitle provides the clue as to what is going on. The labourers are trying to find the body of a baby, who is the subject of a police investigation. The young woman is the child’s mother. Unmarried, she had the baby in secret, smothered it at birth, and disposed of its body. She knows that if her baby is discovered, her punishment will be severe. But this was the only course open to her, as having a baby out of wedlock was against accepted religious and moral standards of the day.

The following year, Henningsen’s Farmers in the Capital (1887) shows migrants freshly arrived in Copenhagen from the country. The father is speaking to a mounted policeman, presumably asking him for directions to their lodgings.

Krohg’s The Struggle for Existence (also translated as The Struggle for Survival) (1889) 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. A policeman, wearing a heavy coat and fur hat, walks in the distance, down the middle of the icy street, detached from the scene.

Henningsen’s Evicted from 1892 shows a family of four being evicted into the street in the winter snow. With them are their meagre possessions, including a saw suggesting the father may be a carpenter. In the background he is still arguing with a policeman.

José Uría’s After a Strike, from 1895, revolves around a strike and its violent consequence. The scene is a large forge that’s apparently standing idle because of a strike. At the far right is a row of mounted police, and what may be lifeless bodies laid out on the ground. Inside the factory a woman, presumably a wife, kneels and embraces her child, beside what is presumably the dead body of her husband, who was a worker there. Close to his body is a large hammer, apparently the instrument of his death. In the distance, one of two policemen comfort a younger woman.

The role of police forces has remained as controversial ever since.

Somewhen around late versions of macOS Monterey, and certainly by the release of Ventura, macOS started to use cryptexes to load Safari and parts of the operating system including dyld caches, rather than installing them to the Data volume. Over a period of three months, cryptexes were also used to install Rapid Security Responses (RSRs) in an experiment that was quickly discontinued. What I hadn’t realised until recently was that they are also used to deliver much of the additional components required to support Apple Intelligence features in Apple silicon Macs. This article looks as how that works.

Cryptexes

These first appeared on Apple’s customised iPhone, its Security Research Device, which uses them to load a personalised trust cache and a disk image containing corresponding content. Without the cryptex, engineering those iPhones would have been extremely difficult. According to its entry in the File Formats Manual from five years ago (man cryptex), ‘A cryptex is a cryptographically-sealed archive which encapsulates a well-defined filesystem hierarchy. The host operating system recognizes the hierarchy of the cryptex and extends itself with the content of that hierarchy. The name cryptex is a portmanteau for “CRYPTographically-sealed EXtension”.’

In practice, a cryptex is a sealed disk image containing its own file system, mounted at a randomly chosen location within the root file system during the boot process. Prior to mounting the cryptex, macOS verifies it matches its seal, thus hasn’t been tampered with. Managing these cryptexes is the task of the cryptexd service with cryptexctl. Because cryptexes aren’t mounted in the usual way, they’re not visible in mount lists such as that produced by mount(8).

System cryptexes

Once kernel boot is well under way, APFS mounts containers and volumes in the current boot volume group, followed by others to be mounted at startup. When those are complete, it turns to mounting and grafting the three standard system cryptexes:

• os.dmg, around 6 GB (macOS 15.5), containing system components such as dyld caches;
• app.dmg, around 23 MB, containing Safari and supporting components;
• os.clone.dmg, apparently a copy of os.dmg and the same size.

AI cryptex collection

About 5 seconds later, and over 14 seconds after APFS first started work, it checks and grafts a series of 23 cryptexes primarily involved with Apple Intelligence features. These are handled one at a time in succession, each reported in a sequence of log entries as follows (times in seconds after an arbitrary start).

First the Image4 file containing the cryptex is validated
9.434431 root_hash_execution_cb_mobile_asset:3066: image4_trust_evaluate: successfully validated the payload and the manifest

Then it’s grafted into the file system of the Data volume as a ‘PFK volume’. In this extract I omit the bulk of the cryptex’s name using […] for the sake of brevity.
9.434465 apfs_graft:695: disk3s5 Grafting on a PFK volume
9.434509 graft_dev_init:480: disk3 UC_[…]_Cryptex.dmg GRAFT (compiled @ Apr 22 2025 19:49:43)
9.434514 graft_dev_init:484: disk3 UC_[…]_Cryptex.dmg device_handle block size 4096 real block size 4096 block count 11264 features 0 internal VEK
9.434695 nx_mount:1308: UC_[…]_Cryptex.dmg initializing cache w/hash_size 512 and cache size 512
9.437484 nx_mount:1630: UC_[…]_Cryptex.dmg checkpoint search: largest xid 15, best xid 15 @ 7
9.437497 nx_mount:1657: UC_[…]_Cryptex.dmg stable checkpoint indices: desc 6 data 31
9.438117 er_state_obj_get_for_recovery:8420: UC_FM_LANGUAGE_INSTRUCT_3B_CONC No ER state object for volume RevivalB13M201388.UC_[…]_Cryptex - rolling is not happening, nothing to recover.
9.438124 apfs_log_op_with_proc:3263: UC_FM_LANGUAGE_INSTRUCT_3B_CONC grafting volume RevivalB13M201388.UC_[…]_Cryptex, requested by: mobileassetd (pid 457); parent: launchd (pid 1)
Note the volume name starts with Revival. Names of all other cryptex volumes in the AI collection start with the same code name, except for the PKI cryptex examined below, which uses Creedence instead. Perhaps these are a reference to Creedence Clearwater Revival?

The root hash of the cryptex file system is then authenticated
9.438156 graft_dev_blockmap_lut_switch_to_metadata_based_if_needed:1312: UC_FM_LANGUAGE_INSTRUCT_3B_CONC lut contains 26 extents, 3 of which contain metadata
9.438160 is_root_hash_authentication_required_osx:387: UC_FM_LANGUAGE_INSTRUCT_3B_CONC Release kext with internal build: 0, ARV disabled: 0, booting xid: 0
9.438164 is_root_hash_authentication_required_osx:418: UC_FM_LANGUAGE_INSTRUCT_3B_CONC strict graft, root hash authentication failure is required
9.438167 is_root_hash_authentication_required:557: UC_FM_LANGUAGE_INSTRUCT_3B_CONC Strict Graft, root hash authentication is required
9.438179 authenticate_root_hash:642: UC_FM_LANGUAGE_INSTRUCT_3B_CONC successfully validated on-disk root hash
9.438191 apfs_lookup_ge_jobj_id:5028: disk3s5 Found OBJID 0x66a1b8 type 3

The graft is then completed.
9.438195 apfs_graft:1045: disk3s5 Graft ino 6557986, jobj_id range 6725836+76
9.438396 apfs_graft:1138: disk3s5 successfully grafted ino 6557986 on dir 6725835, dev_name [UC_[…]_Cryptex.dmg]

Fortunately, these log entries provide the inode number for the location of the grafted cryptex, and that can be used in Mints to obtain its full path.

Among the AI cryptex collection is a secure public key infrastructure (PKI) trust store, located at
/System/Library/AssetsV2/com_apple_MobileAsset_PKITrustStore/purpose_auto/[…].asset/AssetData/Restore/SECUREPKITRUSTSTOREASSETS_SECUREPKITRUSTSTORE_Cryptex.dmg
In the log, this is recorded as being 4.2 MB in size, and that is the same size as reported for the .dmg file by the Finder. Disk images are in APFS (Case-sensitive) format, and might be identical to their equivalents provided for iOS and iPadOS.

When mounted, that disk image becomes a volume named Creedence11M6270.SECUREPKITRUSTSTOREASSETS_SECUREPKITRUSTSTORE_Cryptex. That contains many property lists, certificate data, a SystemRootCertificates keychain, and two property lists that are grafted into /System/Library/CoreServices.

The names of all 23 cryptex disk images included in the macOS 15.5 AI cryptex collection are given in the Appendix. All are given as being compiled at Apr 22 2025 19:49:43, the same as the system cryptexes, implying that they were installed as part of the macOS 15.5 update. The whole sequence of processing the AI cryptexes took 0.78 seconds to complete, and the total size of disk images mounted in that period was 7.2 GB, which is similar to the reported size of additional files required to support AI.

Conclusions

• Apple silicon Macs running macOS 15.5 with AI enabled load 23 additional cryptexes to support AI, totalling 7.2 GB.
• Those AI cryptexes are grafted into the Data volume, in paths starting /System/Library/AssetsV2.
• All except one have volume names starting with Revival
• One cryptex is a secure PKI trust store, whose volume name starts with Creedence instead.
• These cryptexes are installed and updated as part of macOS updates, although they could also be installed or updated separately, for example when AI is enabled.
• If a Mac shows an unusual mounted volume with a name starting with Creedence or Revival, that’s almost certainly the respective disk image, which should normally be hidden and not visible in the Finder.

Appendix

Disk image names for the AI cryptex collection in macOS 15.5 (Apple silicon):

• UC_FM_LANGUAGE_INSTRUCT_3B_CONCISE_TONE_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_TEXT_EVENT_EXTRACTION_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_PROOFREADING_REVIEW_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_VISUAL_IMAGE_DIFFUSION_V1_BASE_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_BASE_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_IF_PLANNER_NLROUTER_BASE_EN_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_MAIL_REPLY_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_DRAFTS_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_SUMMARIZATION_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_AUTONAMING_MESSAGES_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_URGENCY_CLASSIFICATION_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_MESSAGES_REPLY_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_PROFESSIONAL_TONE_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_SAFETY_GUARDRAIL_BASE_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_TEXT_EVENT_EXTRACTION_MULTILINGUAL_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_CODE_GENERATE_SMALL_V1_BASE_GENERIC_H16_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_MAGIC_REWRITE_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_300M_BASE_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_TEXT_PERSON_EXTRACTION_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_CODE_GENERATE_SAFETY_GUARDRAIL_BASE_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_TEXT_PERSON_EXTRACTION_MULTILINGUAL_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• UC_FM_LANGUAGE_INSTRUCT_3B_FRIENDLY_TONE_DRAFT_GENERIC_GENERIC_H16S_Cryptex.dmg,
• SECUREPKITRUSTSTOREASSETS_SECUREPKITRUSTSTORE_Cryptex.dmg.

Given in the order that they are grafted.

Apple has just released updates to XProtect for all supported versions of macOS, bringing it to version 5304, and to XProtect Remediator for all macOS from Catalina onwards, to version 152. As usual, Apple doesn’t release information about what security issues these updates might add or change.

Yara definitions in this version of XProtect add two private rules for Shebang, to match shell scripts by ‘shebang’, and _golang_macho, to match machos compiled by Golang. There are also 19 new rules for a novel family of what appear to be stealers based on the name BONZAI, including MACOS.BONZAIBONANZA.AUTO, MACOS.BONZAIBONANZA.TAAP, MACOS.BONZAIBONANZA.TAFI, MACOS.BONZAIBONANZA.VACA, MACOS.BONZAIBONANZA.VASN, MACOS.BONZAIBONANZA.FU, MACOS.BONZAIBONANZA.SC, MACOS.BONZAIBARRICADE.PE, MACOS.BONZAIBARRICADE.PA, MACOS.BONZAIBARRICADE.KE, MACOS.BONZAIBLASTER.FU, MACOS.BONZAIBLASTER, MACOS.BONZAIBLASTER.TA, MACOS.BONZAIBONDER.SO, MACOS.BONZAIBONDER.PE, MACOS.BONZAIBONDER.TEPL, MACOS.BONZAIBONDER.LA, MACOS.BONZAIBONDER.FU, and MACOS.BONZAIBANANA.

XProtect Remediator doesn’t change the list of scanner modules.

There are changes to the list of Bastion rule 2 paths, and four new Bastion rules 14-17. These cover sending AppleEvents to browsers, the Finder and Terminal, mach-lookup for com.apple.pasteboard.1, and writing to a long list of shell-related hidden directories in the user’s Home folder.

These are probably the greatest changes to XProtect’s Yara rules and Bastion rules for more than a year.

You can check whether these updates have 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 these as named updates in SilentKnight, their labels are XProtectPayloads_10_15-152 and XProtectPlistConfigData_10_15-5304.

Sequoia and Tahoe systems only

The XProtect 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 5304 but your Mac still reports an older version is installed, you may be able to force the update using
sudo xprotect update

By 1915, Robert Polhill Bevan (1865–1925) was treasurer of the London Group, successor to Walter Sickert’s Camden Town Group, and had formed his own group centred on his studio in Cumberland Market, Camden Town, London. The latter exhibited at the Goupil Gallery, London, and was later to be joined by Edward McKnight Kauffer and CRW Nevinson, who was to achieve fame as a War Artist.

Despite the landscapes he painted in the countryside of the Blackdown Hills in East Devon, Bevan’s more acclaimed paintings were mainly views in London, particularly those of Saint John’s Wood and Belsize Park.

Hay Carts, Cumberland Market from 1915 is another view of London’s last hay market, close to Bevan’s studio. The bales shown were made by mechanical baling machines and brought to London by barge.

The Green House, St John’s Wood from about 1918 shows one of many mansions that had been built in this former suburb of London, developed into low-density housing for the more affluent of the nineteenth century. This area is now known for being home to cricket with the major ground of Lord’s, and the Abbey Road Studios used by the Beatles and other famous bands. Bevan introduces a motor taxi opposite two horse-drawn carts, signalling the decline of the latter.

The Caller at the Mill from 1918-19 probably shows a scene in East Devon, painted during one of Bevan’s summer visits.

Also in typical Blackdown Hill country is The Ford, from the same period.

Bevan painted A Devon Cottage (Luppitt) in about 1920, in the same area to the north of Honiton.

In 1922, Bevan was elected a member of the New English Art Club.

He painted this view of Aldwych in central London in 1924. This is a crescent off the Strand, to the east of Charing Cross. At the left is a motor omnibus, while drinking at the water-trough beneath the memorial is one of the remaining working horses of London, which by now were well in decline.

Mount Stephen from 1924 shows one of the farms close to Luppitt in East Devon, presumably painted during one of Bevan’s summer visits.

I also have one undated watercolour of Bevan’s.

Landscape with Three Trees was most probably painted en plein air in the south-west of England, as an alternative to his early oil sketches.

Robert Bevan died of cancer of the stomach on 8 July 1925, in London. The following year his life and work were remembered in a retrospective, but he didn’t gain the recognition he deserved until his centenary in 1965, and remains seriously underrated even today.

References

Wikipedia.
Robert Upstone (ed) (2008), Modern Painters: The Camden Town Group, Tate Publishing. ISBN 978 1 85437 781 4.

This week’s batch of app updates includes two for working with metadata, a fun obfuscator of text, and my in-house performance test for storage. In each case, they have been given a new app icon that should display well in all versions of macOS from Big Sur to Tahoe. Their windows have been overhauled to accommodate Tahoe’s larger controls, and they have been rebuilt.

Spotlight and metadata

Metamer gives access to 16 of the most useful types of metadata that can be saved as extended attributes to any file, and others that are text-based if you wish. It has a built-in scratchpad you can use to assemble groups of keywords, for instance. It thus gives access to a wide range of metadata that you can use in Spotlight search.

Metamer version 1.6 is now available from here: metamer16
from its Product Page, and via its auto-update mechanism.

To accompany that is Spotcord, which scans folders to build vocabularies of keyword metadata (kMDItemKeywords in Spotlight’s terms), subjects and other specified types. Although it can look for those Spotlight derives from image analysis, experience shows that few are likely to be accessible outside Spotlight itself. This is the first release version of Spotcord, which had lingered in beta far too long.

Spotcord version 1.0 is now available from here: spotcord10
and from its Product Page. It doesn’t use the auto-update mechanism, though.

Text obfuscation

Dystextia is a bit of fun using Unicode lookalike characters to obfuscate Roman text. For example, it will convert this line into
Dуstехtіа іs а bіt оf fun usіng Unісоdе lооkаlіkе сhаrасtеrs tо оbfusсаtе Rоmаn tехt.
or even
Dу𝚜𝚝ех𝚝іа і𝚜 а bі𝚝 о𝚏 𝚏𝚞𝚗 𝚞𝚜і𝚗ɡ U𝚗ісоⅾе ⅼоо𝚔аⅼі𝚔е с𝚑а𝚛ас𝚝е𝚛𝚜 𝚝о оb𝚏𝚞𝚜са𝚝е Rо𝚖а𝚗 𝚝ех𝚝․
if you prefer. This is easy to reverse using AI, but throws find and spellchecking out of the window.

Dystextia 1.9 is now available from here: dystextia19
from its Product Page, and via its auto-update mechanism.

Storage performance testing

In contrast, today’s last update is the app I use to measure read and write speeds of storage, from internal SSDs to external hard disks and NAS systems. This offers a flexible range of test methods, all based on the same API calls used by apps to ensure they represent real-world performance. This comes with a detailed Help book that explains how testing and data analysis are performed.

Stibium version 1.2 is now available from here: stibium12
from its Product Page, and via its auto-update mechanism.

Coming next

My next batch of updates concludes the straightforward ones, and will bring Dintch, Fintch and Cormorant.

I currently don’t intend updating any of my command tools like blowhole, as they appear to continue working fine in Tahoe.

I have started work on updates to Unhidden, SilentKnight/Skint, and the Viable family of virtualisers. Each needs more work before they will work properly with Tahoe, in the case of SilentKnight/Skint a complete new version designed for future macOS.

I currently don’t intend updating ArchiChect, Taccy, Signet, Scrub, LockRattler or the command tool silnite for Tahoe, as they’ve now been superseded or outdated. If you want one of those reinstated, please let me know.

During the 1920s, in the last years of his career, Lovis Corinth’s paintings reached a new peak, both in their quantity and their innovative exploration of colour and texture.

Although Corinth was clearly relishing this intensity, his Large Self-portrait in Front of Walchensee (1924) shows his race against the effects of age.

The Trojan Horse (1924) is Corinth’s last major painting from classical myth, showing the wooden horse made by the Greeks in order to gain access to the city of Troy, so they could sack and destroy it. The lofty towers and impregnable walls of the city are in the background. The select group of Greek soldiers who undertook this commando raid have already been concealed inside the horse, and those around it are probably Trojans, sent out from the city to check it out before it was taken inside.

Although there are suggestions as to an allegorical relationship between this painting and the First World War, Troy had been a hot topic in Berlin since the excavations at Hisarlık in Turkey in the late nineteenth century by Heinrich Schliemann and Wilhelm Dörpfeld.

Corinth also painted for fun: this superb depiction of a Königsberger Marzipantorte (Royal Marzipan Cake) (1924) must have been completed at great speed before his family consumed his model.

The Jochberg at Walchensee (1924) shows this 5,141 foot (1,567 metre) mountain dividing the Walchensee from the Kochelsee.

Walchensee, Vegetable Garden (1924) was painted away from his normal vantage point above the lake, to include the colours and textures of this vegetable patch.

Walchensee (1924) is a watercolour sketch reportedly painted on vellum.

Carmencita, Portrait of Charlotte Berend-Corinth in Spanish Dress (1924) probably doesn’t refer directly to the famous Spanish dancer Carmen Dauset Moreno, who had died in 1910. Charlotte Corinth, or Berend-Corinth, had continued painting in the early twentieth century, and joined the Berlin Secession in 1912. She also painted actively when at their chalet. In 1933, she emigrated to the USA, where she produced the first catalogue raisonné of her husband’s paintings. She died in 1967, so I am unable to show any of her paintings.

Corinth painted members of his family more often at this time, as he probably suspected he was reaching the end of his artistic career. In Wilhelmine in a Yellow Hat (1924) his shy daughter is starting to show some of her mother’s vivacity.

Thomas in Armour (1925) shows Corinth’s older child, then 21, wearing the suit of armour that had appeared in several of Corinth’s paintings over the years, in a visual record of his son’s transition into adult life.

Corinth painted Ecce Homo at Easter, 1925, as an act of meditation to mark the festival. It shows the moment that Pilate presents Christ to the hostile crowd, just before the Crucifixion. Christ has been scourged, bound, and crowned with thorns, and Pilate’s words are quoted from the Vulgate translation, meaning behold, the man. In keeping with his earlier contemporary interpretations of the scenes of the Passion, Pilate (left) is shown as an older man in a white coat, and the soldier (right) wears a suit of armour.

Corinth completed this in four days. This was bought for the Nationalgalerie in Berlin in 1929, but in 1937 was condemned by the Nazi party as being ‘degenerate art’. Thankfully, it escaped destruction when it was bought by the art museum in Basel in 1939.

The Beautiful Woman Imperia was one of the last paintings that Corinth completed in the late spring of 1925, and his final fleshly work. It’s based on Balzac’s anthology of tales Cent Contes Drolatiques from 1832-37. This shows the courtesan Imperia, naked in front of a priest, in surroundings suggesting contemporary decadent cabarets, or a far older ‘perfumed room’.

Corinth’s Last Self-Portrait, painted just two months before his death in 1925, is unusual in showing him with his reflection in a mirror. He is now balding rapidly, his cheeks sunken, and his eyes are bloodshot and tired. That summer he travelled to the Netherlands to view Old Masters, including Rembrandt and Frans Hals. He developed pneumonia, and died at Zandvoort on 17 July, four days before his sixty-eighth birthday.

He had painted more than a thousand works in oil, and hundreds of watercolours. He also made more than a thousand prints, an area of his work that I haven’t touched on. Ironically, it was the rise of the Nazi party from 1933 that prevented him from achieving the international recognition his work deserved.

References

Wikipedia.

Lemoine S et al. (2008) Lovis Corinth, Musée d’Orsay & RMN. ISBN 978 2 711 85400 4. (In French.)
Czymmek G et al. (2010) German Impressionist Landscape Painting, Liebermann-Corinth-Slevogt, Arnoldsche. ISBN 978 3 89790 321 0.

I hope that you enjoyed Saturday’s Mac Riddles, episode 315. Here are my solutions to them.

1: It came with a tumbler from Camelot in 1993, then opened in 2008.

2: Replacement for 3 to avoid royalties with transparency has just turned three.

3: CompuServe animated its palette with 256 colours but we still can’t agree how to say it.

The common factor

I look forward to your putting alternative cases.

Much of the data handled on and off our Macs and devices is protected by encryption. That has been designed to ensure encryption can’t be broken in a reasonable amount of time using current and future computing resources. Using conventional computers, for instance, it would take a great many years to break data encrypted using 256-bit AES, so in practice this has been considered to fully secure, for the past.

Threat

For the last 50 years or so, researchers have been working on quantum computers that could radically change that. Instead of using normal binary bits with values of 0 and 1, those use qubits measured in terms of probability, making them non-deterministic. That changes the way they work, and some tough problems in the binary world can be speeded up so much that, given a suitable quantum computer, they could compute in far shorter times. This has already been applied to greatly reduce search times in big data, and has the potential to break most recent forms of encryption.

Progress in making suitably powerful quantum computers to be able to decrypt data encrypted using classical techniques has been slow, but we’re now reaching the stage where that’s likely to be feasible in the next year or three. Now is the time to start deploying more advanced forms of encryption to protect our data from the imminent future.

Data in transit

In February last year, Apple announced that iMessage was transitioning to the use of protocols that are quantum-secure, and those were introduced the following month in macOS 14.4, iOS and iPadOS 17.4 and watchOS 10.4. When macOS 26 Tahoe and its matching OSes are released in a couple of months, they bring further important steps towards fully secure encryption, in encrypted network connections using quantum-secure mechanisms in TLS 1.3.

Classical encryption is at its most vulnerable when encryption keys are exchanged over the Internet, and public key systems can be completely broken by quantum methods. Thus, Apple’s first changes are being made to protect data in transit, where it can be intercepted and stored for later decryption using a quantum computer. Securing iMessage is an important start, and the new features in Tahoe and its sisters extend similarly improved protection to other data transfers.

Apple’s operating systems provide support for encryption and related techniques in CryptoKit, making quantum-secure methods available to third-party apps as well. For OS 26, CryptoKit gains Module-Lattice based key encapsulation or ML-KEM, part of the FIPS 203 primary standard for general encryption. Signatures gain the Module-Lattice based digital signature algorithm or ML-DSA, part of FIPS 204.

Data in storage

Whereas public key cryptography systems can be completely broken by quantum attacks, the news for symmetric key schemes such as those used in FileVault and APFS encryption is considerably better. Although quantum computers will be able to break classical techniques more quickly, that should prove neither quick nor easy.

In Intel Macs with T2 chips and Apple silicon Macs, encryption keys are protected by the Secure Enclave, never leave it, and are never exposed to the main CPU. Attempts to gain access through the Secure Enclave are subject to robust defences: for example, the Secure Enclave Processor allows only 5 attempts to enter a Mac’s password before it increases the time interval enforced between entry attempts, and after 30 unsuccessful attempts no more are allowed at all, and the Mac has to be fully wiped and reset.

Trying to remove internal storage is designed to frustrate the attacker. Although internal storage is referred to as an SSD, the storage used isn’t complete in the sense that you couldn’t remove it and install it in another computer, and most of its disk controller functionality is performed by sections in the host chip, including its Secure Enclave. Even models like the Mac Studio that have socketed storage don’t make this easy: remove its special SSD module and it won’t work in another Studio unless it has been completely wiped and reset, destroying its keys and contents.

Apple’s strategy for the protection of encrypted internal storage is thus intended to block access at every level, so that post-quantum brute-force decryption would have little if any impact should it become available in a few years. The standard encryption method used, AES-256 in XTS mode, may need to be revised as quantum decryption becomes more feasible, and Apple is now recommending that doubling the key size should be sufficient to make encryption suitably resistant to forcing with a quantum computer.

Summary

• Future quantum computers will be able to break some classical encryption methods.
• Public key methods used to protect data in transit across the Internet are the most vulnerable to quantum attack.
• macOS 14.4 and iOS 17.4 have started progressively replacing iMessage protection to make it resistant to quantum attack.
• OS 26 will extend that protection to cover connections over TLS 1.3, where supported by servers.
• Protection already provided to stored data, such as FileVault, is considered to remain robust.
• Encryption of static data can be made more robust to quantum cryptography by doubling key size from 256 to 512 bits.

Resources

Quantum computing (Wikipedia)
Post-quantum cryptography (Wikipedia)
FIPS 203-206 (NIST standards)
Securing iMessage with PQ3 (Apple)
macOS Tahoe TLS 1.3 support (Apple)
Cathie Yun presentation Get ahead with quantum-secure cryptography, WWDC 2025 (via Apple Developer app etc.)
CryptoKit for developers (Apple)

On the second day of this weekend’s visit to the fjords of Norway, we’ve reached the twentieth century, and a pupil of Eilert Adelsteen Normann (1848-1918).

Clearly inspired by Normann’s views of the fjords, Elisabeth Grüttefien’s style is quite distinct, as shown in her undated Fjord Landscape. Her greens are more vibrant, and there are some fluffy red patches in her blue sky.

In her Fjord with Steamer from about 1900, she includes a sailing boat and one of the larger steamships, just as might have appeared in Normann’s paintings.

She also found some different motifs. In Fjord Landscape, also from about 1900, it is spring, and there’s still plenty of snow left from the winter. Groups of birch trees have yet to come into leaf.

Sadly, Elisabeth Grüttefien then vanished, and her paintings stopped.

Nikolai Astrup, the last landscape artist in this series, spent most of his life in the hamlet of Jølster, to the north of Sognefjord, where his father was the parish priest. He trained under two great Norwegian painters, Harriet Backer and Christian Krogh, and under Lovis Corinth in Berlin. Unlike the previous artists, Astrup was no visitor to the fjords, he lived among them.

Kollen, translated as The Barren Mountain, or simply The Fell, (1905-06) shows one of the huge rocky outcrops towering over the coast of fjords and lakes in this part of Norway. Astrup must have painted this during the late winter.

Astrup recorded the public rites of the community, as in his Funeral Day in Jølster (before 1908). With the grandeur of the hills behind, a small party escorts the coffin of one of the villagers. His father, the pastor, leads the procession to the small churchyard, a rite that had taken place many times over the preceding centuries, and was to follow the artist’s own early death in 1928.

Grey Spring Evening (before 1908) is one of Astrup’s finest paintings of Jølster Lake. In its suffuse light, the hill dominating the opposite bank has rich earths and a shallow strip of green fields near the water’s edge. The pale green spring foliage on the trees in the foreground is muted, and a rowing boat out in the middle of the lake seems a tiny speck lost in the midst of nature.

Jølster Lake is fed from meltwater from Jostedalsbreen, and there’s still abundant snow on the mountains in Astrup’s view of A June Night and Old Jølster Farm, with its lush carpet of marsh marigolds.

His prints clearly influenced his painting style. Kari – Motif from Sunde (c 1918) shows an elfin figure of a girl who has been painted as if in an illustration, or perhaps one of Carl Larsson’s popular albums.

The Cold Frame Mound (c 1921-28) reveals the Astrup family vegetable garden by their house at Sandalstrand, including the ‘cold frame’ of the title. Despite their name, cold frames actually protect plants from the cold, and are used to enable earlier starting of vegetable crops. Sinking the cold frame into the ground (and siting it on a high point) protects its contents from ground frosts, while covering it with glazed windows ensures that daylight can raise the air and soil temperatures within it.

For much of his career, Astrup’s prints and paintings had informed and influenced one another; The Befring Mountain Farms (c 1924-28) is an example of his mixing the media in a single work, coupling woodblock printing with oil painting. It shows an extended series of farm buildings not far from Jølster Lake.

Astrup uses the natural environment to generate one of his most magical works. Two people are engaged in milking a goat by the entrance to a building in the left foreground. The farm buildings have turf roofs with luxuriant growth, in one case sporting a small tree. Spindly birches stand next to them, their leaves shimmering in the light of the crescent moon. That moon is reflected in a small pond surrounded by marsh marigolds in full flower. You can hear the silence among the massive rock bluffs towering over the lake, and that in the centre looks like the head of an owl, watching over the stillness of the night.

Yesterday’s brief history of Internet search carries a lot in between its lines, some of it increasingly sinister. From the assumption that search results should be ranked by popularity rather than quality of content, to Google’s latest AI overviews, so much runs counter to all we had come to learn in previous millennia.

Many of our greatest insights and ideas have been far from popular at the time, and some have been so reviled that their authors have been ostracised as a result. Indeed, the origin of the term ostracisation refers to a practice that the ancient Greeks recognised led to popular but flawed outcomes, when the great were rejected by ill-informed opinion of the mob.

By a quirk of fate, the screenshot of Google Scholar in use showed search results from 2011 for the terms autism vaccine, a topic that has recently returned to the headlines. Claims made by some of today’s politicians have been propagated using the same principles as PageRank until millions of people have been fooled into believing what were demonstrably fraudulent results. The mob are about to throw away decades of public health improvements for the sake of palpable lies.

We now have new tools to amplify such nonsense, in ‘AI’ built on large language models, and they’re starting to supplant search. In doing so, they’re going to destroy the raw material they feed on to generate their summaries.

Before about 2000, the great majority of information was printed on paper. There must have been a dozen or more specialist Mac magazines, and a steady stream of popular books about Mac OS and how to get the best from it. Even Apple was a prolific originator of thoroughly well written reference guides in its Inside Macintosh series, published by Addison Wesley. In the following couple of decades, most of those vanished, replaced by websites financed by advertising income, hence the industry dominated worldwide by Google.

Blogs originated in the mid-1990s and by about 2010 had reached a peak in their numbers and influence. Since then many have ceased posting new articles, or simply vanished. The generation that took to the web around 25 years ago are now trying to retire, sick of spam comments and the vitriolic spite of those that abuse them. Unsurprisingly the next generation are less enthusiastic about taking to their blogs, leaving some to make money from ephemeral video performances.

If there’s one thing that Google could have done to further the decline of the remaining online publications and blogs it’s to plunder their contents, massage their words with the aid of an LLM, and present those as overviews. When you’ve researched an article over several days and spent many hours writing and illustrating it, it’s more than galling to see an AI present its paraphrase as its own work.

These AI overviews range from the accurate, through repetitious waffle, to those riddled with errors and contradictions. Had they been written by a human, I’d describe them as a shameless and inaccurate plagiarist who has little or no understanding of what they’re plagiarising.

You can see examples of this by making quick comparisons between Google’s AI overview and the articles that it links to. For instance:

• Ask Google “what is the boot volume structure in ios?” and compare that overview with this article. For added entertainment, try the same with iPadOS, and spot the differences.
• Ask “what does runningboard do in macos?” and notice how sources given date from 2019 and 2021, when RunningBoard had only just been discovered. Refer to a more recent account such as that here, to see how out of date that overview is, and how much it has changed in Sequoia.

There’s also an element of unpredictability in those overviews. Repeat one after a couple of minutes, and the results can be quite different.

Although Cloudflare has developed a method that enables commercial publishers to control Google’s ability to scrape their content and plagiarise it, for the great majority of us, there seems little we can do but watch page views continue to fall to levels below those before the Covid pandemic. If you’ve got something better to do with your time than write for your blog, this is when you get seriously tempted.

But Google is digging a deep hole for its future. As the supply of new content to feed its LLM falls, most new articles will be generated by AI. All it will have to plagiarise then will itself be plagiarism, and it will amplify its own errors. By not referring searches to content, Google will also have killed the geese that lay its golden eggs, and lost much of its advertising revenues.

We’ll then be back full circle to curated web directories of the remaining reliable sites.

With summer here at last, if you’re in the Northern Hemisphere, it’s time to head north away from the heat and spend a weekend exploring the fjords of Norway in the company of some of the nation’s great landscape artists. Today we’ll see the development of painting during the nineteenth century, then tomorrow we’ll conclude with the early twentieth century.

We start with the founding father of the golden age of painting in Norway, Johan Christian Claussen Dahl, who was born in Bergen, Norway.

In February 1827, Dahl painted one of the finest winter landscapes of a Norwegian fjord, Winter at Sognefjord. This is the largest and deepest of all the Norwegian fjords, shown deserted apart from a few crows gathered around the base of what appears to be a pinnacle of ice. This might be the famous Balder or Frithjof memorial stone at Leikanger.

Hans Gude was in the next generation, and in the earlier part of his career collaborated with fellow-countryman Adolph Tidemand.

Among the results of this collaboration are some of their most spectacular works, such as Bridal Journey in Hardanger (1848). Gude’s highly detailed and realistic landscape is set in the far south-west of Norway, in the region to the east of Bergen, where one of the world’s largest and most spectacular fjords carves its way from glacier to the sea.

Sandvik Fjord (1879) is Gude’s startlingly detailed depiction of a view from above Sandviken, now the northern suburbs of the Norwegian city of Bergen, looking to the west and the island of Askøy.

The most prolific of those who painted the fjords was Eilert Adelsteen Normann, who like many Norwegian artists of the century trained in Germany, in Düsseldorf. He was responsible for attracting many visitors to Norway, who bought his paintings, and in the early 1890s for helping Edvard Munch to success.

Normann’s From Romsdal Fjord, painted in 1875, is the earliest of his dated works that I have located. It shows the ninth longest fjord in Norway, carving its way through this huge mountain gorge. A small party of well-dressed people have arrived in small boats, for a picnic on a rock spit. A sailing boat is gliding slowly along the mirror surface of the water, and in the far distance is a steamer.

A couple of summers later, Normann returned to the same fjord and painted Romsdal Fjord (1877), using a similar formula for its staffage. Next to his signature, at the lower left, the artist states that this work was painted not in Norway but when he was back in Düsseldorf.

Munken gård in Esefjord was painted on the shore of this tributary to the mighty Sognefjord, in the south-west of Norway, near Normann’s summer cabin.

One of the regular passenger and cargo ferry services steams up an unidentified fjord in Normann’s The Steamship.

Sognefjord, Norway returns to Norway’s longest and deepest fjord, as it carves its way due east from the southern bulge of the coastline. This view features Normann’s favourite small craft, and the sky and rock have become very painterly.

Sognefjord is fed by meltwater from Jostedalsbreen, the largest glacier in continental Europe, and the Hurrungane mountain range, rising to its highest peak Store Skagastølstind, with an elevation of 2,405 metres (7,890 feet). Like several Norwegian mountains, that was first climbed by the English mountaineer William Cecil Slingsby, on 21 July 1876. Slingsby made many first ascents in Norway during his thirty-year climbing campaign there from 1872, and is often regarded as the father of Norwegian mountaineering.

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

1: It came with a tumbler from Camelot in 1993, then opened in 2008.

2: Replacement for 3 to avoid royalties with transparency has just turned three.

3: CompuServe animated its palette with 256 colours but we still can’t agree how to say it.

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.

Searching the Internet, more recently its web servers, has proceeded in four main phases. Initially, humans built structured directories of sites they considered worth visiting. When those couldn’t keep pace with the Internet’s growth, commercial search engines were developed, and their search results were ranked. Around 2000, Google’s PageRank algorithm became dominant for ranking pages by their popularity. Then from late 2024 that is being progressively replaced with AI-generated summaries. Each of these has been reflected in the tools provided by Mac OS.

Directories

In the earliest years of the Internet, when the first web servers started to appear, and files were downloaded using anonymous FTP, users compiled their own lists by hand. Some curated directories were made public, including one maintained by Tim Berners-Lee at CERN, and another at NCSA. Individuals started using Gopher, a client to discover the contents of servers using the service of the same name. The next step was the development of tools to catalogue Gopher and other servers, such as Veronica and Jughead, but it wasn’t until 1993 that the first search engine, W3Catalog, and a bot, the World Wide Web Wanderer, started to transform Internet search.

Berners-Lee’s directory grew into the World Wide Web Virtual Library, and still exists, although it was last updated several years ago, most is now hosted elsewhere, and some is broken. The most famous directory was originally launched in 1994 and was then known as Jerry and David’s Guide to the World Wide Web, later becoming Yahoo! Directory. This offered paid submission and entry subscriptions, and was closed down at the end of 2014.

The favourite of many (including me) was launched as GnuHoo in 1998, and later that year, when it been acquired by Netscape, became the Open Directory Project, then DMOZ, seen here in the Camino browser in 2004. Although owned by AOL, it was maintained by a volunteer community that grew rapidly to hold around 100,000 links maintained by about 4,500 volunteers, and exceeded a million links by the new millennium. DMOZ closed in 2017 when AOL lost interest, but went on as Curlie using the same hierarchy.

Sherlock was first released in Mac OS 8.5 in 1998. As access to the web grew, this came to encompass remote search through plug-ins that worked with new web search engines.

Those were expanded in Sherlock 2, part of Mac OS 9.0 from 1999 and shown above, and version 3 that came in Mac OS X 10.2 Jaguar in 2002.

Indexing and ranking

Human editors couldn’t keep pace with the growth of the web, and demand grew for searching of indexes. This posed the problem of how to rank pages, and development of a series of ranking algorithms, some of which were patented. The first to use links (‘hyperlinks’) was Robin Li’s RankDex, patented in 1996, two years before Sergey Brin and Larry Page’s PageRank that brought their success in Google.

Ranking search results wasn’t new. In the late twentieth century, sciences started measuring the ‘impact’ of published papers by counting their citations in other papers, and university departments and scientific journals laid claim to their greatness by quoting citation and impact indexes. Early search ranking used features such as the frequency of occurrence of the words in the search term, which proved too crude and was manipulated by those trying to promote pages for gain. The obvious replacement was incoming links from other sites, which also quickly became abused and misused.

Research into networks was limited before 1998, when Jon Kleinberg and the two founders of Google entered the field. As with citation indexes before, they envisaged link-based ranking as a measure of popularity, and popularity as a good way of determining the order in which search results should be presented. They also recognised some of the dangers, and the need to weight incoming links to a page according to the total number of such links made by each linking site. Oddly, Kleinberg’s prior work wasn’t incorporated into a search engine until 2001, by which time Brin and Page were powering Google to dominance, and in June 2000 provided the default search engine for Yahoo!

This is Yahoo! Search seen in Firefox in 2007, by which time it was using its own indexing and search engine.

PageRank and algorithms

Google grew prodigiously, and became rich because of its sales of advertising across the web, a business dependent on promotion of its clients, something that could be achieved by adjusting its PageRank algorithm.

Although it’s hard to find now, at one time Google’s Advanced Search was widely used, as it gives more extensive control. Here it’s seen in Safari of 2011.

Google Scholar gives access to published research in a wide range of fields, and was introduced in late 2004. Here it’s seen in use in 2011, listing work that’s recently become topical again. Scholar doesn’t use the same PageRank-based algorithm for ranking its results, but does give substantial weight to citation counts.

When Apple replaced Sherlock with Spotlight in Mac OS X 10.4 Tiger in April 2005, web search defaulted to newly-arrived Safari and Google’s search engine. Its major redesign, in OS X 10.10 Yosemite in 2014, merged web and local search into Global Spotlight, the search window that opens from the Spotlight icon at the right end of the menu bar. That in turn brought Spotlight Suggestions, which became Siri Suggestions in macOS Sierra.

This shows a search in Global Spotlight in macOS 10.12 Sierra, in 2017.

Apple has never explained how Siri Suggestions works, although it appears to use machine learning and includes partial results from web search probably using Google. It offers a taste of what is to come in the future of Internet search.

Summarising

Google started the transition to using Artificial Intelligence in 2024, and that September introduced Audio Overview to provide spoken summaries of documents. This year has brought full AI overviews, in which multiple pages are summarised succinctly, and presented alongside links to the pages used to produce them. Although some can be useful, many are vague and waffly, and some blatantly spurious.

We’ve come a long way from Tim Berners-Lee’s curated directories, and PageRank in particular has transformed the web and more besides.

References

Wikipedia:
Gopher
Web directory
Search engine
Google Scholar

Amy N Langville and Carl D Meyer (2006) Google’s PageRank and Beyond: the Science of Search Engine Rankings, Princeton UP. ISBN 978 0 691 12202 1.

In the autumn of 1919, Lovis Corinth and his family had moved into their chalet at Urfeld, on the shore of Walchensee (Lake Walchen), to the south of Munich. From then until Corinth’s death, they divided their time between the bustle of Berlin and their garden of Eden by the lake and the mountains.

Corinth combined his new enthusiasm for painting floral arrangements with a gentle portrait of his eleven year-old daughter in Flowers and Daughter Wilhelmine (1920). The flowers shown are dominated by amaryllis, arums, and lilacs, and its composition reflects Wilhelmine’s shyness.

During the final six years of his life, Corinth must have painted more than sixty views around their chalet in Bavaria, of which I can only show a small selection. Like many others, Landscape at the Walchensee with Larch (1920) was painted from an observation point on a hill across from their chalet. This painting was bizarrely classified as being ‘degenerate art’ by the Nazis in 1937.

The local terrain produces some deceptive appearances, but many of Corinth’s late landscapes have marked tilting in their horizontals, and Walchensee by Moonlight (1920) even shows the same leftward lean in its verticals. This had been prominent in the earliest of his paintings in 1912, following his stroke. Here it probably reflects his shift of emphasis from form to areas of colour, particularly the impasto reflections of the moon on the lake’s still surface.

In 1921, Corinth was awarded an honorary doctorate and made a professor of arts by the University of Königsberg, where he had started his training.

Walchensee, Landscape with Cow (c 1921) is another view painted from his ‘pulpit’ vantage point across from the chalet.

Throughout his career, Corinth had made loose watercolour sketches, usually as preparatory studies for finished oil paintings. Now he started painting watercolour landscapes, such as his Walchensee, Evening Air (1921), capturing the colours of dusk.

Pink Clouds, Walchensee (1921) is another watercolour showing the rich colours of land and sky as the sun sets.

In 1922, his work led the German pavilion at the Venice Biennale, with a total of thirty of his paintings on display.

Red Christ (1922) is the last, most striking and original of all his many scenes of the Crucifixion. Although thoroughly modern in its approach and facture, he chose a traditional wood panel as its support, in keeping with older religious works. The red of Christ’s blood, spurting from the wound made by a spear, and oozing from his other cuts, is exaggerated by the red of the clouds and the sun’s rays.

Easter at Walchensee was painted from their chalet in 1922, as the winter snow was melting on the tops of the hills.

Corinth also painted some watercolours indoors. His Flower Vase on a Table (1922) has patches of pure, high-chroma colour for the flowers and the armchair at the right, and few suggestions of form.

During this period of frenetic painting, Corinth appeared at first to flourish in the sunshine and fresh air. His Self-portrait in a Straw Hat from 1923 shows him looking in rude health.

Susanna and the Elders (1923) revisits the Old Testament story from the book of Daniel, which had brought him early success in 1890. The two versions he had painted then followed tradition, and show the naked Susanna being spied on by two elders, who then tried to blackmail her. Here he shows the three figures talking, as the elders put their proposition to Susanna.

Back in his ‘pulpit’ above the lake, Tree at Walchensee (1923) has the most rectilinear form of all his views of Walchensee, set by the horizontal snow-line and the trunk of the tree.

Walchensee in Winter (1923) is another evocative snowscape.

Chrysanthemums II (1923) is my favourite of his late floral works, as the texture of the paint matches the fine petals perfectly.

References

Wikipedia.

Lemoine S et al. (2008) Lovis Corinth, Musée d’Orsay & RMN. ISBN 978 2 711 85400 4. (In French.)
Czymmek G et al. (2010) German Impressionist Landscape Painting, Liebermann-Corinth-Slevogt, Arnoldsche. ISBN 978 3 89790 321 0.

From its first announcement of Apple silicon Macs on 22 June 2020, there has been speculation as to when support of Intel models will cease. Now Apple has given exceptionally clear details of its future intentions, and we have a clearer idea of what’s coming in macOS Tahoe, we can make plans at last. This article looks at the years ahead. In each case, major events are scheduled to occur with the annual transition of macOS to the next major version, normally in September-October.

2025

Final security update for macOS 13 Ventura, ending support for:

• iMac 18,1-3
• MacBook 10,1
• MacBook Pro 14,1-3.

If you’re still running Ventura on a Mac capable of Sonoma or later, now is the time to plan the upgrade.

2026

Final security update for macOS 14 Sonoma, ending support for:

• MacBook Air 8,1-2.

First release of an Arm-only version of macOS, 27. However, that and all its updates will continue to include full support for running Intel binaries using Rosetta 2 translation. macOS 27 will be the last major version that supports Rosetta 2 fully in Virtual Machines.

2027

Final security update for macOS 15 Sequoia, ending support for:

• iMac 19,1-2
• iMac Pro
• Mac mini 8,1
• MacBook Air 9,1
• MacBook Pro 15,1-4 16,3.

First release of macOS 28, with full Rosetta 2 support removed. Limited Intel binary support will continue for “older unmaintained gaming titles” only. As a result, virtual machines running macOS 28 will no longer be able to run most Intel binaries.

2028

Final security update for macOS 26 Tahoe, ending support for all remaining Intel models:

• iMac 20,1-2
• Mac Pro 7,1
• MacBook Pro 16,1-2 16,4.

T2 firmware updates are almost certain to cease with the end of support for macOS 26. Major third-party vendors are likely to stop providing Universal binaries, as they too drop support for macOS 26 and Intel models. Apple may decide to remove x86 support from Xcode 29, but hasn’t yet made any statement either way.

Benefits of upgrading macOS in Intel models

Although macOS Sequoia and Tahoe have brought some new features for Intel Macs, much of Apple’s emphasis now requires Arm systems. Major reasons for upgrading your Intel Mac to the most recent version of macOS it can run include:

• Third-party support. Major software vendors like Microsoft normally only support their products on versions of macOS still supported by Apple.
• Safari is only updated in supported versions of macOS.
• Bug fixes. Although new versions bring their own bugs, the chances of an existing bug being fixed in the current release of macOS are far greater than it being fixed in an older version.
• Security vulnerabilities. Only the current version of macOS gets a full set of fixes in each round of security updates, and the older two supported versions often lag the current one.
• Enhancements. Some new features are still provided for both platforms.
• Compatibility. If you already use Apple silicon Macs, or intend doing so, they are more compatible when running the same version of macOS. One topical example is Tahoe’s new ASIF disk image format.
• Quantum-secure encryption. Apple has already started to transition to cryptographic techniques designed to remain secure as and when quantum computers are used in the future to break older methods. This started with iMessage last year, and Apple has announced that macOS 26 Tahoe will support quantum-secure encryption in TLS. This is unlikely to be added retrospectively to older versions of macOS.

I hope you find that helpful in your planning, and wish you success in whatever you choose.

This is the third of four articles providing brief summaries and contents for this series of paintings telling myths from Ovid’s Metamorphoses, and covers parts 37-54, from the fall of Icarus to King Midas.

Daedalus and his son Icarus try to escape Crete using wings of feathers and wax. Icarus flies too near the sun, his wings melt and he falls to his death. Daedalus’ nephew is transformed into a partridge.

37 The fall of Icarus

Calydon troubled by a wild boar. Many heroes hunt the animal, and Meleager is successful. He shares the glory of his prize with Atalanta, but his uncles take the prize, so Meleager kills them both.

38 The Calydonian Boar Hunt

Meleager’s mother Althaea avenges the deaths of her brothers by throwing a log on the fire, causing her son’s death. His sisters are turned into birds. Theseus travels home from the boar hunt and is entertained by Achelous, who explains how nymphs were transformed into the islands of the Echinades.

39 The feast of Achelous

Lelex tells of Jupiter and Mercury seeking hospitality when visiting Phrygia. Only the humble and poor couple Philemon and Baucis entertain them. The gods save them from a flood that drowns everyone else. They’re later transformed into intertwining oak and lime trees.

40 Hospitality to strangers and virtue rewarded

Achelous tells those at his banquet of three shape-shifters: Proteus the old man of the sea, Erysichthon who sold his daughter to assuage his hunger until he consumed his own body, and Achelous himself.

41 Shape-shifters and the Old Man of the Sea

Achelous and Hercules wrestle for the hand of Deianira. Achelous turns himself into a bull, and Hercules wrenches off one of his horns, which becomes cornucopia, the Horn of Plenty.

42 Wrestling for the Horn of Plenty

Hercules marries Deianira, but the centaur Nessus tries to abduct her, so Hercules kills him. Nessus gives Deianira some of his blood, and tricks her later into impregnating one of Hercules’ shirts with it, causing him to incinerate himself on a pyre. He is then turned into a god.

43 The death of Hercules

The birth of Hercules made difficult by Juno and Lucina. Other myths of Hercules as an infant.

44 The birth of Hercules

Dryope picks lotus flowers, and is punished by transformation into a Lotus Tree. Byblis dissolves into a spring after falling in love with her twin brother. A daughter raised as Iphis, a boy, who was transformed into a man immediately before marrying the woman Ianthe.

45 Dryope, Byblis and Iphis

Orpheus marries Eurydice, who is bitten by a snake and dies. He travels to the underworld and pleads for her to be allowed to return with him. That’s approved, provided he doesn’t look back. Near the end of their return journey, he does look back, and she fades away back into the underworld. He then shuns women for three years in his grief.

46 Orpheus and Eurydice

Cyparissus befriends a stag, then accidentally kills it, and in his grief is transformed into a cypress tree, now grown near cemeteries. Orpheus tells of the young Ganymede, who was abducted by Jupiter and taken to Mount Olympus to be cupbearer to the gods.

47 The cypress tree, and the abduction of Ganymede

Hyacinthus, lover of Apollo, is killed by the god’s discus, and transformed into the purple hyacinth flower.

48 Killed by Apollo’s discus

Pygmalion rejects libidinous behaviour in women, and remains celibate. He carves a statue of a woman in ivory, and asks Venus for a bride like her. His statue is transformed into a woman, they marry, and have a daughter Paphos.

49 Galatea transformed from a statue

Myrrha is made pregnant by her father following a deception. He tries to kill her, but she flees and calls on the gods, who transform her into a myrrh tree. Nevertheless, her baby is born, and becomes Adonis.

50 The making of myrrh and birth of Adonis

Venus tells Adonis of the story of Atalanta, who had been told not to marry, and became a fast runner. Hippomenes challenges her to a race for her hand in marriage. He tricks her during that by dropping three golden apples provided by Venus, and beats her to the finish as a result. He didn’t thank Venus for her help, so the couple make love in a shrine to Cybele. As punishment they are transformed into lions to draw Cybele’s chariot.

51 The race between Hippomenes and Atalanta

Despite the warnings of his lover Venus, Adonis goes hunting, is gored in the groin by a wild boar, and dies. His blood is turned into the red anemone.

52 Death of Adonis

Orpheus is attacked by a mob of Bacchantes, torn limb from limb, and dies. His remains are dispersed into rivers, and his soul reunited with Eurydice. The Bacchantes are transformed into an oak wood.

53 The death of Orpheus

Bacchus grants the wish of King Midas, and everything he touches is transformed into gold. This proves a disaster, so Bacchus removes that gift. Midas loses a music contest with Apollo, for which he is given ass’s ears.

54 How Midas got his touch and his ears

This week I have another group of four little utilities whose windows have been overhauled, and have new app icons to meet the requirements of macOS Tahoe. Each of these new versions requires macOS Big Sur or later.

Finder aliases

If you have old Finder aliases that need to be checked and repaired, Alifix will do that job with you. Use it to scan a folder containing those aliases, and it will warn you which can’t be resolved any longer, and can rewrite those that need to be updated.

Alifix version 1.4 is now available from here: alifix14
and from its Product Page. As it seldom needs updating, it doesn’t use the auto-update mechanism.

APFS sparse and clone files

As you can tell by its name, Sparsity started off as a means of creating APFS sparse files for test purposes. In addition to that, it has a valuable scanning feature that will detect and report details of all sparse, clone and purgeable files in a selected volume or folder. Information reported includes both the nominal and actual size of each file, so you can see which sparse files are saving the most space on disk.

Sparsity version 1.4 is now available from here: sparsity14
and from its Product Page. It too doesn’t use auto-update.

UTI file types

Give UTIutility a filename extension and it will tell you its Uniform Type Indicator (UTI, also UTType), traditional Mac OSType, MIME type, Pasteboard type, and a list of UTIs it conforms to. You can also find the same information from those other properties. This too has a crawler that will search through a volume or folder and compile a list of all the UTIs it encounters there. Its Help book contains an extensive reference to UTIs to help you get the most out of them.

UTIutility version 1.4 is now available from here: utiutil14
and from its Product Page. It doesn’t use auto-update.

Natural language

For many years, macOS has had built-in features to handle and parse natural languages including French, Spanish and German. Nalaprop uses these features to analyse text files, or text pasted into the left view in its main window. That text can then be parsed by downloadable linguistics modules supplied by Apple, and each word displayed in colour according to that word’s part of speech or grammatical type. From that it can automatically construct dictionaries or concordances of words used in that text, arranged by part of speech, and giving word frequency for each.

Nalaprop comes with a multilingual demonstration file to show how well it copes with language transitions.

Here it has parsed and coloured the text in the middle according to part of speech, for two languages, English and French. To the right of those is the dictionary it has compiled, ending verbs and starting the list of nouns. At the far right is a colour key for parts of speech.

In this demonstration, Charles Dickens’ novel David Copperfield has been parsed, a total of nearly 360,000 words. Currently such large documents are analysed in the main thread, so you’re likely to see a spinning beachball during parsing, but can still switch freely to other apps when that’s taking place. Those with Apple silicon Macs will see that analysis is performed in a single thread running on one P core, so all the other P cores remain free to run other tasks. I was hoping to use different threads for this, but it proved too complicated to incorporate in this particular version.

Nalaprop version 1.4 is now available from here: nalaprop14
from its Product Page, and via its auto-update mechanism.

Enjoy!

Here are the 21 icons for those of my apps so far ported to be compatible with Tahoe.

You don’t have to collect all in the series, though.

Compared to the number who have painted themselves in their studio, painting galleries have been an unusual theme for interiors. My examples start with a couple of fanciful images, but soon transfer to some of the more famous, as they went public during the late eighteenth and nineteenth centuries.

Giovanni Paolo Panini’s paintings of Ancient Rome (1757, above) and Gallery of Views of Modern Rome (1759, below) are almost certainly wholly imaginary, although some of their figures look to have been identifiable as leading collectors of the time. These may have been an ingenious device for the artist to show a dazzling array of his own views, of course.

A more accurate reflection of the excesses attained by some is in Johann Zoffany’s Tribuna of the Uffizi (1772-77). This shows a section of one room in the palace that had belonged to the Medici family in Florence. It had only recently (1765) been opened to the public when Zoffany painted this for Queen Charlotte, who never visited Italy let alone the Uffizi, although she was the wife of King George III. Several of the paintings included are familiar, including some by Raphael, and it might repay careful study to determine whether the collection is accurate.

As the middle classes were gaining better access to pictures in the nineteenth century, the hoarding of paintings by the upper classes was becoming extreme. Robert Huskisson’s painting of Lord Northwick’s Picture Gallery at Thirlestaine House (1846-47) not only shows one quite modest collection of the time, but reinforces how few people were able to enjoy the paintings secreted in the mansions of the rich.

John Rushout, the second Baron of Northwick (1770-1859), moved his collection from Northwick Park to Thirlestaine House when it grew too large for his own residence. When he died in 1859, he had no children, and this collection was sold off and dispersed around the world.

William Powell Frith’s last great human panorama shows A Private View at the Royal Academy, completed in 1883. Although he was a Fellow from 1853 until his retirement in 1890, his can’t have been an easy relationship with the British art establishment. This work gives some insight into the frictions within the Academy, as Oscar Wilde is seen at the right holding forth about art, to the dismay of Frith’s friends nearby. Frith had opposed the Pre-Raphaelite and Aesthetic movements, and, like Frederic, Lord Leighton (also shown in this painting), was a great traditionalist.

For Henri Gervex, depicting A Session of the Painting Jury of the Paris Salon was subtle revenge for their refusal of his most famous work Rolla in 1878. The painting the jury are voting on here is a ‘classical’ nude, thus acceptable, compared with Gervex’s of a naked prostitute, thus deemed immoral.

At the turn of the nineteenth to twentieth centuries, Louis Béroud emerged as the uncontested specialist in painting the interiors of galleries, specifically the Louvre in Paris. From then until the First World War, he seems to have painted little else.

At the Louvre (1899) is the earliest work of his that I can find showing the interior of the Louvre, although the pretty young lady posing beneath a painting of the deposition of Christ is merely sitting, holding her umbrella, and looking decorative. Nearer the nonchalant, even disinterested, guard is Correggio’s Venus and Cupid with a Satyr (also known as Jupiter and Antiope) from 1528, one of the gallery’s great treasures, and something of a favourite of Béroud.

If you have visited the Louvre, you will be familiar with the many copyists who work there. Some are students who are improving their skills by copying the Masters, but many are painters who sell those copies on. Béroud shows a copyist chatting to a man in The Rubens Room in the Louvre (1904).

He then seems to have become obsessed with painting copyists, and in An Artist in the Louvre with Correggio’s Jupiter and Antiope (1908) returns to the Correggio. Note the use of a sheet of scrap paper under the copyist’s easel, to ensure that no drips of paint ended up on the floor. All but one of Béroud’s copyists seem to be women, although today you’re almost as likely to come across a man. I suspect that reflects the more limited opportunities for women to train as painters at that time.

He started catching his models during their more social moments, as with the discussion taking place in his Copyists in the Louvre (1909). The large painting shown here is Watteau’s Embarkation for Cythera (1717); to the left is Greuze’s The Milkmaid (1780), and to the right his Broken Pitcher (1785).

The Joys of the Flood (in the Medici Gallery) (1910) is probably the best of all Béroud’s gallery interiors. This time the copyist is the artist himself, the only man to appear in that role in these works. Rubens’ huge The Disembarkation of Marie de’ Medici at Marseilles (1621-25) bursts into life, as its water starts to flood the Louvre and its three nudes step out onto the floor.

Béroud had a close call with the police on 21 August 1911, when he had been painting a copy of Leonardo da Vinci’s Mona Lisa, and the original went missing. This was first noticed by Béroud, who reported the theft, and so became embroiled in the crime.

After his moment of fame, Béroud returned to painting his copyists. In his Painter Copying a Murillo in the Louvre from 1913, the only easel occupied is in front of Murillo’s The Young Beggar (c 1645).

Douglas Fox Pitt’s The Stafford Gallery from 1912 is an unusual watercolour with its elevated view recalling Spencer Gore’s Gauguins and Connoisseurs painted the previous year. While Gore’s painting (no image of which is in the public domain) shows a landmark exhibition of Post-Impressionist paintings in the same gallery, Fox Pitt shows an early exhibition of the Scottish Colourist J D Fergusson held from 9 March 1912. The painting shown most prominently is Fergusson’s La Dame aux Oranges (c 1908–09), whose location is now unknown. To the left is The Red Shawl (1908), and on the right is Le Manteau Chinois (1909).

Finally, this painting by Sir John Lavery (1856–1941) of The Opening of the Modern Foreign and Sargent Galleries at the Tate Gallery, 26 June 1926 (1929) was commissioned by the art dealer Sir Joseph Duveen to mark the opening of these new galleries by King George V. The King and Queen are seen on the dais, beneath a few of the Tate’s collection of paintings by JMW Turner. Duveen’s name is recorded in the inscription above the doorway.

Some time in the next week or two, Apple is expected to release its first public beta of macOS 26 Tahoe. This article is intended to help you decide whether to risk or resist that tempting offer.

As with Sequoia last year, to install the public beta-release you no longer have to download a special enabler from a closed website. This is now done through an extra option in Software Update. All you need to do is sign up here, and once the public beta is released you should see it offered in Software Update, when your Mac is signed in using the Apple ID you signed up with. There’s also an option there that caters for those who wish to use a different Apple ID for betas.

Can your Mac run Tahoe?

Tahoe is officially supported on just four models of Intel Macs with T2 chips, and all Apple silicon Macs. It’s expected that at least some older Macs will be able to run Tahoe using OCLP, but won’t do so until that has been updated later this year.

The full list of supported models is:

• MacBook Pro 16-inch 2019, and 13-inch 2020 with four Thunderbolt ports,
• iMac 2020,
• Mac Pro 2019,
• all Apple silicon Macs.

As in Sequoia, Apple Intelligence is only available on Apple silicon models.

What do you get in the beta?

Apple’s official account of new features is fairly detailed. I have drawn attention to a new disk image format in this article.

Changes are dominated by Liquid Glass and other features in its new interface, which is still evolving. This brings changes in app icons, and may require further work to adjust interface elements to accommodate its changes.

Other significant new features include:

• Magnifier app using a connected camera;
• Journal app now available in macOS;
• Phone app available in macOS;
• Metal version 4.

Apple provides extensive release notes for betas.

Although Tahoe is thoroughly macOS version 26, you will discover that it can also pose as version 16, as explained here.

Can you lose that Mac?

The next question you should ask is whether you could afford to completely lose your Mac for a while, as a result of a problem with the beta. Although that’s most unlikely to happen, it’s a risk you’ve got to be prepared for when you install any pre-release version of macOS.

Never, under any circumstances, install a beta of macOS on any Mac you rely on for production. Betas invariably involve firmware updates, so even if you install the beta on an external disk, it will change your Mac’s firmware. Undoing that is hard enough for an Apple silicon model, and it’s not possible on Intel Macs. All you can then do is wait for another beta, or maybe the final release in the autumn/fall, which should update the firmware to something more compatible.

Betas also normally come with updated versions of key components such as iCloud, the APFS file system and Time Machine. Consider carefully what havoc they could produce if there’s a bug affecting other storage used by that Mac, and its backups.

If the worst comes to the worst, you could end up having to restore that Mac to an older version of macOS. Apple explains how to do that, and you should read that account carefully before making any decision. If you’re thinking of installing betas on an Apple silicon model, beware that process requires another Mac running Apple Configurator 2, or macOS Sonoma or later, and restoring it in DFU mode.

Internal or external SSD?

One way to reduce the risk posed by beta versions of macOS is to install them on external storage. While that can enforce some degree of separation and protection, it still means that firmware is updated, and still brings significant risk of disaster. Don’t try this with a production Mac, even from an external disk.

If you’re going to install the beta on an external disk, you’ll need to be comfortable with the procedure for Apple silicon Macs. Although it does become straightforward with practice, some seem unable to get it to work at all. Intel Macs are far simpler, of course, although one important catch with T2 models is that you have to downgrade their security using Startup Security Utility in Recovery mode, if you haven’t already done so, or they can’t boot from an external disk. This article steps through the procedure.

Multiple systems on the same disk

You can also install multiple boot volume groups on the same disk, letting you choose which version of macOS to start up from. This provides even less separation or protection than installing them on separate disks, so should never be attempted on any production Mac.

Apple recommends that you do this into separate boot volume groups within the same APFS container, which has the great advantage that they share the same free space within that container. However, there are times when that can work against you, and you may prefer to opt for separate containers instead. The choice is yours.

Virtual machine

Some consider the best way of keeping out of trouble when running beta versions of macOS is to install them into a Virtual Machine (VM). This can’t alter the firmware of the Mac hosting the VM, and that alone makes it far safer. This is simplest on Apple silicon Macs, with their extensive built-in support for running virtualised macOS. Use any of the virtualisers, including Parallels, UTM, and my own Viable. Full instructions for Viable are given here, with additional information for Tahoe here.

iCloud

Some betas bring substantial changes to iCloud, and in the past that has caused lasting havoc to accounts and on iCloud storage. I’m not aware of any particular issues that have been reported in this respect with Tahoe betas, but many testers prefer to use a different iCloud account for Macs when running beta-releases of macOS.

Kernel panics

If you do decide to install the Tahoe beta, or have already done so, I have a big favour to ask on behalf of tens of millions of users, and most of Apple’s engineers. By all means take a good look at its new features, and give Apple plenty of feedback on what you think of them. But please pay careful attention to the basics, exercising your Mac with peripherals such as external displays and hubs. Should you discover problems, please work with Apple to ensure that it knows what they are. If you can, test out features such as Time Machine (being careful not to put your existing backups at risk), which seldom get much attention from beta-testers.

In particular, send Feedback reports on any kernel panic your Mac encounters when running a beta. The normal system report, sent after your Mac has restarted, is helpful, but further details are much better still. Even betas should never suffer kernel panics; if yours does, please help Apple’s engineers fix that problem before Tahoe is released.

For those who do beta-test Tahoe, I wish us success, and hope you enjoy testing, and helping Apple make Tahoe even better for all of us.

Apple has just released an update to XProtect for all supported versions of macOS, bringing it to version 5303. As usual, Apple doesn’t release information about what security issues this update might add or change.

This version adds two new rules, for MACOS_SOMA_JUEN and MACOS_SOMA_LLJU, continuing to extend its coverage of the Amos/Soma family of malware.

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

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

If you want to install this as a named update in SilentKnight, its label is XProtectPlistConfigData_10_15-5303

Sequoia systems only

This update has just now been released for Sequoia 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 5303 but your Mac still reports an older version is installed, you may be able to force the update using
sudo xprotect update

Update:

The update was released via iCloud at 2010 GMT.

On 8 July 1925, almost exactly a century ago, the British painter Robert Polhill Bevan died in London following surgery for stomach cancer. Although his paintings have been largely forgotten since, he was one of the active members of groups centred on Walter Sickert, including the Fitzroy Street and Camden Town Groups. He was perhaps the leading artist who recorded London’s final years of working horses. In this article and its sequel next week I summarise his career and show a selection of his paintings.

Robert Polhill Bevan was born in Hove, on the south coast of England near Brighton, and in 1888 started a short period as a student at the Westminster School of Art in London before he moved to Paris to study at the Académie Julian. Although it’s claimed that his fellow students there included Pierre Bonnard and several of those who were later to become Nabis, some of them were already at the École des Beaux-Arts, and it’s not clear whether Bevan ever came into contact with those artists in Paris. He did, though, visit the artists colony at Pont-Aven in Brittany in 1890 and more briefly in 1891.

In the autumn of 1891, Bevan travelled first to Madrid, where he studied the work of Diego Velázquez and Francisco Goya, before going to Tangier. He returned to Brittany in 1893, where he was encouraged by Paul Gauguin and Auguste Renoir. He arrived back in Britain the following year, and moved to Exmoor, where he apparently painted and hunted, a pursuit that had occupied much of his time when he was in North Africa. He married the Polish artist Stanisława de Karłowska in late 1897, and in subsequent years often visited her family estates in central Poland.

During this early part of his career, he often sketched in oils en plein air. Morning over the Ploughed Fields is an example of these paintings from about 1904, and was almost certainly made during one of his visits to Poland. It’s small, with fluid brushstrokes of vivid colour. He divides the almost featureless plain into bands, with blue trees in the distance, and the far splash of a barn. Pinholes at its corners suggest that Bevan painted this on canvas when it was pinned to a board.

In 1905, Bevan had his first solo exhibition, which failed to attract critical attention. He then apparently experimented with a more Divisionist approach.

The Turn Rice-Plough, Sussex from about 1909 shows two ploughmen turning a plough in a field in the south-east of England. Its title is enigmatic: rice wasn’t grown there, and might be a simple error for turnwrest, a dialect name used in Kent and Sussex to describe any type of one-way plough needing to be turned at the end of a furrow as shown here.

Bevan exhibited five paintings in the first exhibition of the Allied Artists’ Association in London in 1908. His work was noticed by Harold Gilman and Spencer Gore, resulting in his being invited to join the Fitzroy Street Group. When Walter Sickert and his close circle were forming the Camden Town Group in 1911, Bevan was invited to be one of its sixteen members, and accepted.

He painted The Cab Horse in about 1910 using ‘anti-realist’ colours, and showed this at the first exhibition of the Camden Town Group. By this time, Bevan had a particular interest in the remaining working horses in London, including that shown here being harnessed to a hansom cab. The figure on the left is removing a blanket from the animal’s hindquarters, although their dress doesn’t suggest this is a cold day.

Bevan’s Horse Sale at the Barbican from 1912 follows Sickert’s advice to paint everyday scenes from life in London, and is a reminder that the city, here in Aldersgate, used to have bloodstock auctions.

The title of Bevan’s painting “Quiet with all Road Nuisances” from about 1912 quotes from the auctioneer’s description of this horse at another sale, and should have made this animal a good purchase for working in town.

After 1910, Bevan stopped visiting Poland in the summer. Instead he spent much of the season among the Blackdown Hills, on the border between Devon and Somerset, where he painted in the Bolham Valley and around the village of Luppitt, to the north of Honiton, Devon.

Like other members of the Camden Town Group, Bevan was a careful draftsman, and his oil paintings often started as sketches before being squared up and transferred to canvas. He drew this view of Swiss Cottage, Hampstead in 1912-13. The Swiss Cottage of the title refers to a part of Hampstead, now in the London Borough of Camden, named after a pub called the Swiss Tavern, now Ye Olde Swiss Cottage. This view shows a parade of shops rather than the pub, and has been carefully projected to a vanishing point off the paper to the far right.

Bevan painted Haze over the Valley in about 1913, when he was spending the summer at Applehayes, a farm in the Blackdown Hills owned by Harold Bertram Harrison (1855–1924), an amateur artist who had studied at the Slade School in London from 1896.

In 1913, Bevan had a further solo exhibition at the Carfax Gallery in London, which had hosted those of the Camden Town Group. When that group transformed into the London Group in 1913, Bevan was elected its treasurer.

During 1914-15, he rented a first-floor studio in Cumberland Market, Camden Town, which was then London’s specialist hay and straw market. Bevan’s studio was the centre for a small group consisting of himself, Gilman, Charles Ginner and John Nash, who became known as the Cumberland Market Group. They exhibited together at the Goupil Gallery in 1915.

The Weigh House, Cumberland Market from about 1914 shows this market in its last years, before it closed in the late 1920s. It was situated between Regent’s Park and Euston railway station, but was demolished during and after the Second World War to form a large housing estate.

References

Wikipedia.
Robert Upstone (ed) (2008), Modern Painters: The Camden Town Group, Tate Publishing. ISBN 978 1 85437 781 4.

I don’t always hit the right keyboard shortcuts. Of those that I commonly get wrong, by far the most serious are Command-W and Command-Q in Safari. While the former just closes the frontmost window, the latter quits the whole app, and can lose the contents of online forms. Why can’t Safari show a confirmation alert before quitting, so I can cancel those unintentional quits?

No alert is going to stop you from using the wrong keyboard shortcut. All it will do is annoy you every time you want to quit Safari and press the correct keys. At worst, when you press Command-Q but intended Command-W, you’ll accidentally click on the wrong button in the alert and go ahead with quitting Safari. The error isn’t quitting the app, it’s pressing the wrong keys, and you’ll continue to do that unless you train yourself out of it, or change your practice to make it more robust.

Historically, keyboard shortcuts for quitting apps and closing windows have long been set as Command-Q and Command-W, as Q stands for Quit and W for Window. It’s unfortunate that the two keys are immediately adjacent, so making it easy to press the wrong one, particularly if you hunt and peck for keys rather than being a touch typist.

If you’re having this problem in Safari, then you’re most likely doing the same in other apps, although its impact there may not be as apparent. That’s because most other apps track changes made in open documents for this purpose, but that’s not something that Safari can do with web pages, as entering your own text within them is tracked by the remote web server, not the browser. This should be mitigated by any website that you’re entering text into: the server should either record those entries as you make them, or at least give you the option of saving them. That’s a basic expectation of accessible website design.

Solution

You may find it helpful to enable Ask to keep changes when closing documents in Desktop & Dock settings. Coupled with disabling the control below, to Close windows when quitting an application, that should bring more protective app behaviour.

It might seem tempting to try changing the shortcut for Quit, but as far as I can see, you can’t do that for all apps. Changing it for just one or a few introduces a major inconsistency, and only increases the risk of error.

The best way you’re going to address this is to remove its root cause, by not pressing Command-Q when you don’t want to quit Safari, and that requires you to close windows a different way. Readily available in macOS is the choice of:

• closing windows by clicking on their red Close button at the top left;
• using the Close command in the File menu;
• assigning a different key combination, and using that to close windows in all apps.

Although you don’t appear able to change the shortcut for Quit in all apps, you can for Close. Open Keyboard settings, click on Keyboard Shortcuts…, then on App Shortcuts at the left. Click on the + tool to add a new shortcut, and set that for All Applications, with a Menu title of Close, and a shortcut of something like Command-Shift-M. You may find Apple’s list of keyboard shortcuts helpful to ensure there are no conflicts. Whichever you choose, you should apply it consistently across all your apps. This keeps it standard and simple and makes it automatic.

Of those three options, my preference is invariably for the first, using the window’s Close button. That’s because it works independently of whichever window is at the front and ‘in focus’. With a little care checking which window you apply it to, it should be completely free of error. The disadvantage of both the Close menu command and its shortcut Command-W is that you might have a different window in focus, so sometimes you will end up closing the wrong one by mistake.

Training

Once you have chosen which to use, train yourself rigorously to use that, and that alone. When working with single-window apps you have the choice of using either, and you should consciously go through the process of thinking that through before deciding which control to use, to remind yourself of what you are doing and why.

The goal is to make closing windows and quitting apps, including Safari, thoroughly reliable processes, so you never make a mistake. That makes any warning alert superfluous, and you’ll then agree that it would only serve to irritate. That’s why better interface guidelines caution against displaying an alert unless there’s a compelling reason to do so, and not routinely whenever quitting an app.

When the First World War broke out on 28 July 1914, Lovis Corinth and his family had only just come to terms with his stroke in 1911, then found themselves living in a country at war. He and most of the other artists in Berlin shared an enthusiastic patriotism that initially gave them a buoyant optimism.

This patriotism was expressed openly in paintings like Corinth’s In Defence of Weapons from 1915. The same suit of armour in which he had posed proudly for his self-portrait prior to his stroke now saw service in the cause of his country.

But both Corinth and his wife were growing older and more tired. Portrait of Charlotte Berend-Corinth (1915) shows a very different woman from the younger mother of a few years earlier. Her brow is now knitted, and her joyous smile gone.

The answer, for Corinth and his family, was to get out of Berlin and enjoy the countryside. In the summer they travelled to Lake Müritz (1915) in Mecklenburg, and Corinth started painting more landscapes again.

He also continued to paint still lifes, such as this wonderful Still Life with Pagoda (1916), with its curious combination of Asian and crustacean objects.

Every year from 1916 to 1918, Corinth returned to his home village Tapiau and the nearby city of Königsberg where he had started his professional career, to see the terrible effects of the war on the people. In 1917, he was honoured by their citizens in recognition of his achievements. A substantial one-man exhibition of his paintings was also held in Mannheim and Hanover that year.

Cain (1917) is probably Corinth’s most significant work from the war years, and continued his series of stories from the Old Testament. He shows Cain finishing off his brother Abel, burying his dying body. Cain looks up to the heavens as he places another large rock on his brother, and threatening black birds fly around.

This stark and powerful painting may also reflect Corinth’s own feelings of his battle following his stroke, and those invoked when the US first entered the war that year, as its remorseless slaughter continued.

Götz von Berlichingen (1917) shows the historical character of Gottfried ‘Götz’ von Berlichingen (1480-1562), a colourful Imperial Knight and mercenary. After he lost his right arm in 1504, he had metal prosthetic hands made for him, that were capable of holding objects as fine as a quill. His swashbuckling autobiography was turned into a play by Goethe in 1773, and a notorious quotation from that led to his name becoming a euphemism for the phrase ‘he can lick my arse/ass’.

Corinth celebrated his sixtieth birthday in 1918, and was made a professor in the Academy of Arts of Berlin. However, with the end of the war and its unprecedented carnage, disaster for Germany, and the revolution, Corinth slid into depression.

Armour Parts in the Studio (1918) is his summary of the situation. The suit of armour is now empty, broken apart, and cast on the floor of his studio.

He still managed some fleshly paintings, such as this Girl in Front of a Mirror (1918).

His self-portraits show clearly the effects of war and age. In Self-Portrait in a White Coat (1918) he’s visibly more gaunt. He is shown painting with his left hand, and has used the open sleeve to stow some brushes for ready use.

Just a year later, his Self-Portrait at the Easel (1919) reveals a still older man, looking directly at the viewer, grappling with the changing times.

Magdalen with Pearls in her Hair (1919), one of Corinth’s few works now in the UK (in the Tate Gallery), is one of several he made of Mary Magdalen, a popular subject for religious paintings. This follows the established tradition of showing her as a composite, based mainly on Mary of Magdala who was cleansed by Christ, witnessed the Crucifixion, and was the first to see him resurrected. Apocryphal traditions held that she was a reformed prostitute, and most depictions of Mary tread a fine line between the fleshly and spiritual.

This is Corinth’s most intense and dramatic depiction of Mary, her age getting the better of her body, and her eyes puffy from weeping. She’s shown with a skull to symbolise mortality, and with pearls in her hair to suggest the contradiction of her infamous past and as a halo for her later devotion to Christ.

Corinth also kept up his floral paintings, here with Roses (1919).

In the summer of 1918, Corinth and his family had first visited Urfeld, on the shore of Walchensee (Lake Walchen), to the south of Munich. They fell in love with the countryside there, and the following year bought some land on which Charlotte arranged for a simple chalet to be built. In the coming years, the Walchensee was to prove Corinth’s salvation, and the motif for at least sixty landscape paintings.

In September of 1919, their new chalet was ready, and the Corinths moved in to watch the onset of autumn. Walchensee, Blue Landscape (1919) appears to have been painted quite early, before the first substantial fall of snow.

October Snow at Walchensee (1919) shows an initial gentle touch of snow as autumn becomes fully established.

Later in the season, when the ground was well-covered with snow, Corinth painted it in Walchensee, Snowscape (1919).

References

Wikipedia.

Lemoine S et al. (2008) Lovis Corinth, Musée d’Orsay & RMN. ISBN 978 2 711 85400 4. (In French.)
Czymmek G et al. (2010) German Impressionist Landscape Painting, Liebermann-Corinth-Slevogt, Arnoldsche. ISBN 978 3 89790 321 0.

I hope that you enjoyed Saturday’s Mac Riddles, episode 314. Here are my solutions to them.

1: Expedition for a panther now in visionOS too.

2: Polished plate is now 1’s most serious competitor.

3: Web pet only lasted a year before the exploder.

The common factor

I look forward to your putting alternative cases.

In this last batch of updates to my apps for the next few weeks, there are four more popular tools, covering Unicode normalisation, appexes, logs, and document versions.

Unicode normalisation

Perhaps the earliest problem with APFS was its lack of Unicode normalisation for file and folder names. This has been a standard way to address accented and other characters that appear identical but have different codes. Apple addressed that, first in providing a normalisation layer on top, then by incorporating it into APFS. However, it can still prove a problem, both within apps and when working with other file systems. Apfelstrudel is a simple app that reveals any potential problems with normalisation, and helps you use the form most appropriate. Version 1.6 has an overhauled interface, and has been rebuilt with a new app icon ready for macOS 26 Tahoe. This version supports macOS from Big Sur onwards.

Apfelstrudel 1.6 is now available from here: apfelstrudel16
from its Product Page, and via its auto-update mechanism.

Appexes

App extensions, or appexes, are numerous in recent versions of macOS, and widely used by apps. This simple utility shows all those managed by PlugInKit, complete with their UUIDs, to help you manage them. Version 1.1 has an overhauled interface, and has been rebuilt with a new app icon ready for macOS 26 Tahoe. This version supports macOS from Sonoma 14.6 onwards.

AppexIndexer 1.1 is now available from here: appexindexer11
and from its Product Page. It doesn’t yet support auto-update.

Logs

Until I started development of LogUI, Ulbow was my preferred app for browsing the Unified log. It has extensive features, with full support for the use of predicates, a chart showing the most frequent sources of log entries, and support for creating and using logarchives, including those from iOS and iPadOS. Unlike LogUI, it uses the log command to obtain log extracts, enabling it to show entry times in nanoseconds. It also displays extracts in Rich Text rather than as a list. Version 1.11 fixes a crashing bug when handling some logarchives, has an overhauled interface, and has been rebuilt with a new app icon ready for macOS 26 Tahoe. This version supports macOS from Big Sur onwards, and is recommended for all users.

Ulbow 1.11 is now available from here: ulbow111
from its Product Page, and via its auto-update mechanism.

Document versions

While Revisionist (also recently updated) provides a suite of tools to work with macOS document versions, Versatility handles one of those tasks with greater ease, creating version archives, and reconstituting them into documents. Simply drop a file onto its window and it will be converted into a folder containing each saved version as a separate document. Drop one of those archive folders onto its window and it will be reconstituted into a document with all those previous versions. This makes it simple to preserve versions when moving documents between volumes or computers, and for archival purposes. Version 1.1 has been rebuilt with a new app icon ready for macOS 26 Tahoe, and supports macOS from Big Sur onwards.

Versatility 1.1 is now available from here: versatility11
from its Product Page, and via its auto-update mechanism.

Next updates

Most of my other apps that haven’t yet been updated for Tahoe should still run perfectly well, although their app icons won’t appear the same as before. I’m now turning my attention to the successor to SilentKnight and Skint, and my virtualisers Viable, ViableS, Vimy and Liviable. Once I’m done with those, I’ll return and complete my other apps.

Enjoy!

Many yellow pigments in use, even into the twentieth century, have shown a pronounced tendency to fade. So when someone comes along offering you a ball of compressed powder that is an intense yellow, and appears more lightfast than alternatives, you’ll believe anything they say. It comes from the urine of cows? No worries, just tell me how much, and when can you deliver?

This seems to have been the story behind the introduction of Indian Yellow into European painting. It had a long track-record of use in and around the Indian sub-continent, where it had featured in watercolours and gouache, and buyers in Europe were only too happy to pay high prices for it when it became available.

This exquisite watercolour miniature showing a Mongol Chieftain and Attendants from the Gulshan Album now in the Freer and Sackler Galleries is a good example, from around 1600. Its yellows and greens have lasted those four centuries very well, and careful testing by Elisabeth FitzHugh has shown the unmistakable presence of the chemicals known to be diagnostic of real Indian Yellow.

The snag with European paintings is that so few works have been tested, and records are so scant, that we don’t even know when Indian Yellow was first used as far west as Europe.

Ernst Willers’ Grove Near Ariccia in the Evening Light (1873) is one of the few European paintings known fairly unequivocally to contain Indian Yellow, probably used to form its rich greens.

We know with rather greater certainty when Indian Yellow came off the market, as by the end of the nineteenth century supplies had essentially dried up. The claim is that, between the late 1500s and then, some Indian herdsmen fed their cows with mango leaves, collected the cows’ urine, and dried it to generate the pigment in balls of compressed powder, some of which still exist. In the nineteenth century, this was increasingly viewed as being cruel to the cows, and the practice was progressively eliminated.

Whether this story is accurate, or indeed the pigment ever saw much use, remains open to doubt. Certain claims, for example of a ban on the production of the pigment from 1908, can’t be verified and appear legendary. But there is evidence that some artists in both India and Europe used the pigment in their paintings.

Its successor Chrome Yellow is part of a family of pigments ranging from pale lemon to deep orange-red, and based on lead chromate, which had been ‘discovered’ as a mineral in the middle of the eighteenth century. Its use as a pigment wasn’t recognised until the early nineteenth century, when it became increasingly popular and versatile.

Initially, supplies were limited and it was expensive. As general commercial demand for the mineral increased, new sources of supply were found, and its price fell accordingly. During the latter half of the nineteenth century it was probably the mainstay yellow and orange in the palette of most painters.

The first evidence of the use of chrome yellow as a pigment in painting dates from just before 1810. Johann Friedrich Overbeck’s painting of Italia and Germania (or possibly Sulamith and Maria) was made in 1828, and is thus from the early adoption phase, when the pigment was expensive and encountered infrequently. Although Overbeck was restrained in his use of colours from orange through to yellow and green, he has achieved a subtle chromatic effect in the green fabric.

Carl Blechen seems to have used Chrome Yellow more extensively in his imposing View of Assisi, painted a few years later in 1832-35. By this time the mixture of Chrome Yellow with Prussian Blue had become known as Green Cinnabar or Chrome Green, although the chromium salt used was not itself green, of course.

By the time that Arnold Böcklin painted this, his first version of Villa by the Sea in 1864, Chrome Yellow had established itself as the standard. However, this is one of a relatively small number of works using the pigment in an almost encaustic mixture of resin and wax.

Chrome Yellow was widely used by the Impressionists and shown at the Salon, and is demonstrated well in Paul Cézanne’s famous painting of The Railway Cutting (c 1870). I believe that most if not all of the greens seen here rely on Chrome Yellow mixed with blue.

As some of the Impressionists, like Claude Monet, generated more income, they could afford to start using the newer and far more expensive cadmium-based pigments that were coming onto the market. Cadmium Yellow is also considerably more lightfast and durable than Chrome Yellow, so during the late nineteenth and early twentieth centuries, many painters switched away from Chrome Yellow.

Walter Crane’s Neptune’s Horses (1892) is one of the later works that apparently still relied on Chrome Yellow.

During the twentieth century, Cadmium continued to displace Chrome in pigments for paints ranging from lemon to orange-red. However, both are potentially environmentally damaging, and in this century more modern, less toxic synthetic organic pigments have been introduced as substitutes. Thankfully, as both Cadmium and Chrome pigments trap their toxic salts in insoluble particles, neither presents any danger to the careful painter when used in paint. For the pastellist, though, inhalation of pigment in dust is a more significant risk.

Chrome Yellow was one of the key colours of Impressionism, and features in many nineteenth century landscapes. No cows ever suffered in its manufacture.

References

NS Baer, A Joel, RL Feller & N Indictor (1986) Artists’ Pigments, vol 1, ed Robert L Feller, Archetype. ISBN 978 1 904982 74 6. (Indian Yellow)
Hermann Kühn, Mary Curran (1986) Artists’ Pigments, vol 1, ed Robert L Feller, Archetype. ISBN 978 1 904982 74 6. (Chrome Yellow)

Summer is an unpredictable time of year. With the Atlantic hurricane season already upon us, we could see searing heat or devastating storms. So it is with the announcements made at WWDC earlier this month: do we have time to try out some of the new features coming in three months, or must we get on with wrangling deprecations and changes looming in macOS Tahoe?

A glance through Apple’s beta release notes might suggest it should prove innocuous, and the great majority of code that’s already happy in Sequoia should have no problems in Tahoe, and so far that’s my experience. That should leave us plenty of time to adjust our app icons so they display properly in the Dock and elsewhere, but it’s there it gets more subtly complicated.

Fix app icons

I don’t think I can over-stress the importance of using Icon Composer for creating replacement app icons. If you don’t, then Tahoe seems determined to deface many traditional icons so they become almost illegible and unusable. The only exemptions are those already conforming to the fixed outline of a square with rounded corners. Any irregularity such as putting a pixel outside that, and they’re relegated to the sin bin.

Here are two icons for the same app viewed in Tahoe. The left one uses a traditional AppIcon.icns icon image, while that on the right is the same circular PNG that has been applied using Icon Composer and added as a .icon file. So far my attempts to get this to work using Xcode 16.4 have been unsuccessful, and the only solution has been to use a beta-release of Xcode 26.

Overhaul controls

That brings with it another problem, as it automatically converts AppKit and SwiftUI layouts so they use Tahoe’s new interface style, and that can generate further work. If you look closely at Apple’s demos of Tahoe at WWDC, you may notice that its controls have changed in size and shape. Not only do most have more rounded corners, but they also have different dimensions.

Interface conversion for apps that use AppKit or SwiftUI is clever, as it preserves the original for use in previous versions of macOS, and only adopts the new style when in Tahoe. Build your app with its smart new Tahoe-compatible icon and run it in Sequoia, and it looks just the same as it did.

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

Those three buttons are significantly wider, so now overlap one another and are wider than the text box below. They need a careful overhaul before they’re ready for Tahoe. Conversion can also have unexpected side-effects: for example, I’ve had some selectable text fields changed to be editable as well. You can see an example that I missed in the left view in XProCheck’s window. I now check carefully through every detail in windows that have been migrated by Xcode to support Tahoe.

This doesn’t just apply to AppKit windows in Interface Builder. Although SwiftUI dynamically positions controls, I’ve found it necessary to increase the minimum width of some views to ensure they remain fully usable.

Aside from any code changes needed, migrating an app to Tahoe thus requires:

• creation of a new app icon using Icon Composer;
• adding the .icon file to the Xcode project and setting it as the app icon;
• careful checking and rectification of all windows and their contents.

NSLog

There’s one last thing that may have escaped your attention in Apple’s release notes: NSLog. When Apple introduced the Unified log in macOS Sierra, it preserved the longstanding use of NSLog as a means of making entries with a minimum of fuss. More formal methods are more cumbersome, although they’re also more powerful, so NSLog still remains popular with developers, at least until Tahoe’s change.

A long way down the release notes, and oddly announced under the subheading of New Features, Apple states that NSLog will no longer record anything of use in its entries in the Unified log, although they’ll still be reported in full in Xcode and to stdout. One of the other purposes of my test app Mallyshag was to verify just what is now recorded by NSLog.

This is the entry obtained using LogUI when running either version of the app in macOS 15.5:

And this is the extent of entries seen in macOS 26:

So what in earlier macOS might have been a useful
Error number 1467296 in Mallyshag
is redacted to the contentless stub <private>.

If you still use NSLog, you’ll almost certainly want to move on to a better alternative, again being careful to avoid ending up with its contents redacted.

Outcomes

Come the release of macOS 26 Tahoe, there’ll be three groups of apps:

• those that haven’t been ported at all, whose icons will be almost unrecognisable;
• those whose icons display correctly, but with flaws in interface controls;
• those that work as expected, with conformant icons and controls.

Some will also write dysfunctional messages in the log, because they’re still using NSLog, although few users are likely to notice that.

That doesn’t take into account those apps relying on alternatives to AppKit and SwiftUI for their interface, as those have a great deal of ground to cover in just a few months if they’re going to be ready in time for Tahoe’s release.

That’s why I’ve started unusually early in getting my apps ready for the autumn/fall. I’m sure that summer still has some surprises in store.

Mallyshag?

This is a local Isle of Wight name for a caterpillar, usually a large and hairy one. It just seemed appropriate.

As one of the primary colours, yellow is a vital paint for artists. For many centuries there weren’t any particularly good greens that were also enduring, so many oil and watercolour paintings have relied on the mixture of blue and yellow to generate most of their greens. This weekend I show and tell the stories of three of the yellow pigments that have featured in well-known paintings. Today’s is about one pigment that went missing from the palette for two hundred years, and tomorrow I’ll consider two other yellows with unusual histories.

For much of that period many of the pigments used in artists’ paints were closely guarded secrets. Their precise manner of preparation, even the source of their ingredients, were considered part of the craft of paint-making, whether performed by a supplier or in the artist’s workshop. On at least one occasion, this led to the loss of a pigment from the palette: Lead-Tin Yellow, widely used in many of the greatest works of art prior to 1750, vanished until its rediscovery in 1940.

Like several other pigments, Lead-Tin Yellow seems to have originated in glassmaking, and there’s some evidence of its use as a pigment in glass made as early as about 400 CE. Its earliest use in paintings probably dates back to Giotto in about 1300, following which it became extremely popular.

My earliest example is this painting in egg tempera attributed to Jacopo di Cione: Noli me tangere from around 1368-70. Examination of the brilliant yellow lining to Christ’s robe has shown that its pigment is Lead-Tin Yellow of type II. That is a variant consisting of a lead-tin oxide with free tin and silicon that’s more strongly associated with glass-making, and prepared slightly differently from the ‘purer’ type I.

Both types of Lead-Tin Yellow have proved robust and stable pigments in a range of different binders, including egg tempera and oils.

The centre panel of Rogier van der Weyden’s St Columba Altarpiece, showing the Adoration of the Magi, from about 1455, has been found to contain Lead-Tin Yellow in the rich yellow sleeve of the king in the centre. This is shown better in the detail below.

By about 1450, Lead-Tin Yellow type I was increasingly being used in paint. For example, the infant Christ’s lemon yellow dress in Ambrogio Bergognone’s The Virgin and Child with Saint Catherine of Alexandria and Saint Catherine of Siena (c 1490) has been found to contain this ‘purer’ type.

Another very similar painting by Bergognone, his The Virgin and Child from 1488-90, has not, as far as I can tell, been examined to test for the use of Lead-Tin Yellow, but I strongly suspect the infant Christ’s dress here contains the pigment too. This is shown particularly well in the detail below.

Although believed to be a stable colour, one of the more surprising examples of the use of Lead-Tin Yellow is in one version of Leonardo da Vinci’s The Virgin with the Infant Saint John the Baptist adoring the Christ Child accompanied by an Angel, better-known as The Virgin of the Rocks. The panel from the S. Francesco Altarpiece of Milan, painted between 1491-1508 and now in the National Gallery in London, is shown here.

The light brown lining of the Virgin’s blue cloak, shown in the detail below, contains Lead-Tin Yellow type I. The version in the Louvre, in which that lining is a bright yellow, doesn’t appear to have been reported on.

Yellow is a prominent colour in the paintings in Paolo Veronese’s series The Allegory of Love. In this the third, Respect from about 1575, Lead-Tin Yellow type II has been found in the primrose yellow impasto on the man’s tunic.

Veronese used type I in the first of the series, and type II in the third and fourth, suggesting that he used different sources of supply for his pigments over this period. The two types appear visually indistinguishable, and don’t seem to handle differently in oil paint.

Several of Peter Paul Rubens’ paintings, including his Hippopotamus and Crocodile Hunt from about 1615, have been found to contain Lead-Tin Yellow, although I don’t know which type he used.

Another fine example of the extensive use of Lead-Tin Yellow, here of type I, is in Rembrandt’s Belshazzar’s Feast (c 1635-38). Many of Rembrandt’s paintings have been found to contain the pigment, but here it has been applied in thick impasto to model the highlights on Belshazzar’s cloak.

Rembrandt here used a double ground, over which he applied earth pigments before applying the uppermost layers of lighter colours, including Lead-Tin Yellow, to model the detail. These are shown in the detail below.

Jan Vermeer is another of the Old Masters whose paintings often contain Lead-Tin Yellow. In The Milkmaid (c 1660), for example, it accounts for much of the pale yellow of the woman’s bodice.

What happened next is rather strange. During the first half of the eighteenth century, Lead-Tin Yellow declined markedly in popularity, and by 1750 it appears to have been replaced by other, sometimes less stable, pigments, including Naples Yellow (highly toxic lead antimonate). Once replaced, the recipes for its manufacture appear to have been lost, and its use was forgotten.

During the eighteenth century, there were also changes in the supply of pigments and paints to artists, and by the nineteenth century most were sourced from specialist colourmen, who appear not to have known about Lead-Tin Yellow as a pigment. By the time that commercial manufacture of oil and other paints became widespread in the late nineteenth century, the pigment had been long forgotten. This was aided by uncertainty over its traditional name, which led to confusion with the pigment Massicot (lead oxide or Lead Yellow).

It was Richard Jacobi, working at the Doerner Institute in Munich in 1940, who stumbled across the pigment when analysing yellow paints in Old Master paintings. He reported his radical findings in 1941, and from the late 1940s and 1950s onwards paint analyses looking for it have been performed quite widely, and have found its extensive use in works between 1300 and 1750. Since then it has even been re-introduced in some commercial paint ranges.

Reference

Hermann Kühn (1993) Artists’ Pigments, vol 2, ed Ashok Roy, Archetype. ISBN 978 1 904982 75 3.

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

1: Expedition for a panther now in visionOS too.

2: Polished plate is now 1’s most serious competitor.

3: Web pet only lasted a year before the exploder.

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.