A Twist


Here’s a surprise: The Book of Knowledge of Ingenious Mechanical Devices, a 1206 manuscript by the Turkish author Ismail al-Jazari, depicts a chain pump in the form of a Möbius strip. A rope bearing a chain of cups dips them successively into a water source at the bottom and then pours them into a course at the top. The single, continuous rope makes two passes through this route, describing the edges of a strip with a half twist so that the cups suspended between the loops are turned 180 degrees with each pass. This would permit the cups to last longer, since they’re worn more evenly, and even a broken cup might still convey some water with every second pass.

(Julyan H.E. Cartwright and Diego L. González, “Mobius Strips Before Mobius: Topological Hints in Ancient Representations,” Mathematical Intelligencer 38:2 [June 2016], 69-76.)



Above: Antonio Cicognara, Saint George and the Princess, tempera on panel, 1475.

Below: Lewis Carroll, Saint George and the Dragon, photograph, 1874.


Of photography Carroll wrote, “It is my one recreation and I think it should be done well.”

Jukebox Groceries


The first automated grocery store in the United States appeared in 1937. At Keedoozle, each customer received a key bearing a roll of paper tape. At a series of display cases, she’d insert her key at each item she wanted and press a button, which would punch a pattern of holes in the tape. At the cashier, an electronic “translator” would total the price and release the requested items through chutes onto a conveyor belt. The customer would wait in a lounge until her packed items were delivered to her.

Founder Clarence Saunders claimed that the automated store required only seven employees, half as many as a traditional supermarket. This permitted a 7.5 percent profit on prices 10 percent lower than competing stores, he said.

The system wasn’t entirely automated — humans kept the stocks filled and bagged the orders — and it could handle only cans and cartons, not fresh meat or vegetables. And it tended to founder when the store got busy. But historians also say that the concept was too far ahead of its time — the American public just wasn’t ready for automated shopping. Only three stores were ever built, and the last closed in 1949.

(Thanks, Abi.)

In a Word

adj. resounding with arms

The Battle of the Somme began with a weeklong artillery bombardment in which more than a million shells were fired at the German lines. A soldier describes the first day:

The sound was different, not only in magnitude but in quality, from anything known to me. It was not a succession of explosions or a continuous roar; I at least, never heard either a gun or a bursting shell. It was not a noise; it was a symphony. And it did not move. It hung over us. It seemed as though the air were full of vast and agonized passion, bursting now with groans and sighs, now into shrill screaming and pitiful whimpering … And the supernatural tumult did not pass in this direction or in that. It did not begin, intensify, decline and end. It was poised in the air, a stationary panorama of sound, a condition of the atmosphere, not the creation of man.

At the Battle of Messines in June 1917, 19 mines comprising 600 tonnes of explosives were detonated, producing the largest man-made explosions in history to that date. One witness recalled that the “earth rocked as though a giant hand had roughly shaken it.”

(John Ellis, Eye-Deep in Hell, 1989, via Joy Damousi et al., eds., Museums, History and the Intimate Experience of the Great War, 2020.)



Allegedly this scheme was invented by a poet who wanted to write all night without interruption. He set up a row of candles and linked the base of each to the top of the next with a piece of twine. When the first candle burned down to the twine, “the latter naturally caught fire, and a tongue of flame would creep up to the adjoining candle, lighting it in the manner desired.”

“The scheme is a pretty example of the brilliancy of simplicity in idea, as compared with the complicated arrangements often devised to secure simple results.”

(James Scott, “Strange Devices,” Strand, August 1895, 184-189.)

A Typographical Banknote


In 1819, as the Bank of England struggled against counterfeiters, T.C. Hansard proposed a note that combined such a variety of typefaces that a lone forger couldn’t hope to duplicate it — the faces descended all the way to Diamond, the smallest available, and the bottom of each note would be filled with 140 lines of fine print containing hidden “private marks,” such as individual letters printed in italic or small capitals.

To create even the authentic version would have required a team of 20 people, from punchcutters to engine makers, to fulfill the typographical and other design flourishes. Hansard estimated that producing the first note would have cost as much as £2,000 and taken up to a year, “but after that the production will be so rapid, that with the labour of four Men only, without the assistance of any Steam Machinery, 40,000 Notes may be produced in a Day of the finest Workmanship, at the Expense, including Paper, of Half a Farthing each Note.”

In the end the proposal wasn’t adopted — small notes were withdrawn from circulation in 1821, and the search was dropped.

(Virginia Hewitt, “Beware of Imitations: The Campaign for a New Bank of England Note, 1797-1821,” Numismatic Chronicle 158 [1998], 197-222.)

Guardian Angel

Image: Wikimedia Commons

In the 1980s, when Nicolae Ceauşescu set about razing central Bucharest, engineer Eugeniu Iordăchescu was despairing the threat to the area’s iconic churches when he saw a waiter carrying a tray of drinks. “I saw that the secret of the glasses not falling was the tray,” he said, “so I started trying to work out how to apply a tray to the building.”

He hit on a method of digging beneath the buildings to insert reinforced concrete supports, then rolling them to new locations using hydraulic levers and mechanical pulleys. Over a period of six years, his team saved more than a dozen churches and other buildings that the Communists had planned to destroy; the 800-ton Schitul Maicilor, above, was moved almost 270 yards from its 18th-century foundations.

The technique Iordăchescu pioneered is still in use today. “He was very proud of his achievements, and even in retirement he spent a lot of time improving and helping others to push the method further on,” his son Nicholas told the New York Times. “He will be remembered for a one-of-a-kind contribution to developing this technology.”

(Thanks, Jason.)

Rise of the Machines

The Janken robot created in 2012 at the University of Tokyo’s Ishikawa Watanabe Laboratory has a 100 percent win rate against human opponents in playing rock paper scissors.

How? Using a high-speed camera, it recognizes within a millisecond which shape its opponent’s hand is beginning to form and chooses the appropriate winning shape.