Tongue Tied

Mark Twain received this letter from a Danish customs officer in 1879:

Please to excuse that I fall with the door in the house, without first to begin with the usual long ribble-row. I want to become the autograph of the over alle the world well known Mark Twain, whose narratives so apt have procured me a laughter.

If you will answer this letter, I will be very glad. Answer me what you will; but two words. If you will not answer me other so write only, that you do not like to write autographs.

Your

Carl Jensen

It’s not known whether he responded, but on the envelope Twain wrote, “Please preserve this remarkable letter.” See Lost in Translation.

Figure and Ground

Swiss artist Markus Raetz created this innovative portrait of Piero della Francesca. Two mobiles are fitted with aluminum plates that are juxtaposed successively as the mobiles rotate. Piero appears between them.

Raetz’s kinetic sculpture of Kiki de Montparnasse, below, uses a similar idea:

Black and White

meyer chess problem

By Heinrich Friedrich Ludwig Meyer. White to mate in two moves.

Click for Answer

Pitching In

At a timber-mill in the Powelltown district (Victoria) it is customary to blow three blasts of the whistle to indicate an accident and six blasts to notify a fatality. One day the six blasts echoed about the hills and men ran from all directions to the mill. But there was no fatality; the ‘whistle’ was produced by a Lyrebird, which had heard the three blasts with some frequency, and, in imitating them, had added three more for good measure. That episode ranks with one related by Mervyn Bill, a forest surveyor, who has written that when he was camped at Hell’s Gates (Victoria), he was annoyed to see, through the theodolite telescope, his men doing certain field operations without the usual instructions. The fact became revealed, subsequently, that they had obeyed ‘instructions’ from a Lyrebird in an adjacent gully, which faultlessly imitated the surveyor’s shrill, staccato code of signals.

– Alec H. Chisholm, Bird Wonders of Australia, 1958

See Technical Fowl.

Digit Jump

digit jump puzzle

Place the digits 1 through 8 into these circles so that no two successive numbers are connected by a line. If we don’t count rotations or reflections, the solution is unique.

Click for Answer

In a Word

monomachy
n. a duel

In 1842, Abraham Lincoln, then an Illinois lawyer, published a letter in a Springfield newspaper criticizing the performance of the state’s auditor, James Shields. Shields, quick to anger, challenged Lincoln to a duel, and the two met on an island in the Mississippi River. As the challenged party, Lincoln was permitted to choose the weapon, and he requested long cavalry broadswords. As he stood 7 inches taller than Shields, this gave him an enormous advantage, which he demonstrated by cutting a branch above Shields’ head. Accounts differ as to how the auditor responded — he either laughed or quailed — but the two agreed not to fight. Lincoln appears to have been embarrassed by the whole affair, and declined to discuss it in later years.

(Thanks, Aric.)

The Wheel Cipher

http://commons.wikimedia.org/wiki/File:Jefferson%27s_disk_cipher.jpg

Thomas Jefferson, already absurdly accomplished by 1795, somehow found time to delve into cryptography, where he devised this cipher system. The letters of the alphabet are printed along the rim of each of 36 disks, which are stacked on an axle. One party rotates the disks until his message can be read along one of the 26 rows of letters, somewhat like a modern cylindrical bike lock. Now he can record the letters in any one of the other 25 rows and send that string safely to another party, who decodes it by reversing this procedure. If the message is intercepted, it’s useless even to someone who has the disks, because he must also know the order in which to stack them, and 36 disks can be stacked in 371,993,326,789,901,217,467,999,448,150,835, 200,000,000 different ways.

This is pretty robust. The cipher below, created in 1915 by U.S. Army cryptographer Joseph Mauborgne, has never been solved. “The known systems from this year (or earlier) shouldn’t be too hard to crack with modern attacks and technology,” writes NSA cryptologist Craig P. Bauer. “So, why don’t we have a plaintext yet? My best guess is that it used a cipher wheel” like Jefferson’s.

mauborgne cipher

(L. Kruh, “A 77-year-old challenge cipher,” Cryptologia, 17(2), 172-174, 1993, quoted in Bauer’s Secret History: The Story of Cryptology, 2013.)

Through the Motions

https://www.google.com/patents/US563578

This “device for teaching swimming,” patented by James Emerson in 1896, teaches good technique mechanically. The teacher places the machine in a swimming pool or open water, the student climbs aboard, the teacher turns crank handle 13, and the machine guides the student through the motions of swimming, “these arm movements being so nearly like those performed by an actual swimmer that the beginner who has these movements mechanically imparted to her arms thereby shortly acquires the swimming arm stroke.” What could go wrong?

https://www.google.com/patents/US563578

Occupational Hazards

In April 1964, British prime minister Alec Douglas-Home was staying at the home of a friend in Scotland. One day when he happened to be alone there, he answered the door to find a group of students from Aberdeen University, who said they were there to kidnap him.

At first Douglas-Home said, “I suppose you realize if you do, the Conservatives will win the election by 200 or 300.” Then he stalled by asking for 10 minutes to pack a few things, and bought further time by offering beer to the students. Eventually his friends returned and the students departed willingly. Douglas-Home never spoke publicly of the incident, as the breach would have imperiled his bodyguard’s career, but in 1977 he mentioned it to a colleague, whose diary entry came to light in 2008.

Related: Australian prime minister Harold Holt disappeared entirely in 1967. He was visiting Cheviot Beach, near Portsea, with friends when he decided to go swimming. When he disappeared from view a search was organized, but it could find no trace of him. The beach is known for its rip tides, so he’s presumed to have drowned, but no body has ever been found.

(Thanks, John.)

Accord

Squeeze six circles into a larger circle so that each is tangent to its two neighbors. Now the three lines drawn through opposite points of tangency will pass through the same point.

Remarkably, this wasn’t discovered until 1974.

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