The Spirit Battery

When the electric telegraph was making its appearance in the 1840s, it was strangely easy to confuse it with spiritualism: Both were uncanny means of talking with absent people through systems of symbols. In a bid for legitimacy, spiritualists appealed to the principles of “electrical science.” In his 1853 book The Present Age and Inner Life, Andrew Jackson Davis proposed a “spirit battery” by which a medium could improve her contact with the spirit world by asking her guests to hold a magnetic rope whose ends were dipped in water-filled buckets made of copper and zinc:

The males and females (the positive and negative principles) are placed alternately; as so many zinc and copper plates in the construction of magnetic batteries. The medium or media have places assigned them on either side of the junction whereat the rope is crossed, the ends terminating each in a pail or jar of cold water. … But these new things should be added. The copper wire should terminate in, or be clasped to, a zinc plate; the steel wire should, in the same manner, be attached to a copper plate. These plates should be dodecahedral, or cut with twelve angles or sides, because, by means of the points, the volume of terrestrial electricity is greatly augmented, and its accumulation is also, by the same means, accelerated, which the circle requires for a rudimental aura (or atmosphere) through which spirits can approach and act upon material bodies.

“We are negative to our guardian spirits; they are positive to us,” Davis wrote. “The whole mystery is illustrated by the workings of the common magnetic telegraph. The principles involved are identical.”

Alarming bonus factoid: When Samuel Morse appeared before Congress in 1838 to seek funding for an experimental telegraph line, some congressmen introduced amendments that would provide funds for research on mesmerism as well. The committee chair wrote, “It would require a scientific analysis to determine how far the magnetism of mesmerism was analogous to the magnetism to be employed in telegraphs.” When the bill came to a vote, 70 congressmen left their seats; many hoped “to avoid spending the public money for a machine they could not understand.”

(From Jeffrey Sconce, Haunted Media: Electronic Presence from Telegraphy to Television, 2000.)


The job of creating voices for Munchkins and Winkies in The Wizard of Oz fell to vocal arranger Ken Darby. “In those days we didn’t have the technical facilities we have now, like speeding up tape,” he said. “I had to figure out how to make the Munchkins sound high-pitched”:

I worked it out mathematically, using a metronome. Then I went to the head of the sound department, Doug Shearer. I told him that if we could record at sixty feet per minute instead of the normal ninety feet per minute and if we sang at a slower pace in a different key, when we played it back at ninety it should sound right. He said there was no way to do that because we didn’t have a variable-speed recorder. Then he said he would try to manufacture a new gear for the sound-recording machine. And it worked. I had the singers sing very slowly and distinctly so the words would be clear when we played it back at a faster speed. Ding … Dong … the … witch … is … dead. When we played it back, it was a perfect one-fourth higher.

“None of the midgets did any of the singing. None of them could carry a tune.”

(From Aljean Harmetz, The Making of The Wizard of Oz, 1977.)

Working Smarter

In 1947 two Harvard undergraduates, William Burkhart and Theodore Kalin, built a primitive machine for doing propositional logic. They had been taking a course in symbolic logic with Willard Van Orman Quine and were tired of solving problems with pencil and paper, so they set about making a machine that would do their homework automatically.

The result of their $150 investment was a small machine that could handle problems involving up to 12 terms in the propositional calculus. The “Kalin-Burkhart machine” marks a milestone in the development of logic machines, but working in the machine’s language is so laborious that using a pencil is faster.

“It is interesting to note that when certain types of paradoxes are fed to the Kalin-Burkhart machine it goes into an oscillating phase, switching rapidly back and forth from true to false,” noted Martin Gardner in Logic Machines and Diagrams (1958). “In a letter to Burkhart in 1947 Kalin described one such example and concluded, ‘This may be a version of Russell’s paradox. Anyway, it makes a hell of a racket.'”


An epic contest from the Annual Green Fair and South West Scythe Festival in Somerset, U.K., June 2010.

One commenter wrote, “Now we know why Death carries a Scythe, not a brushcutter.”

Words Without Language
Image: Wikimedia Commons

In contemporary secretary schools, training emphasizes the inhibition of reading for meaning while typing, on the assumption that such reading will hinder high-speed performance. Some support for this assumption derives from the introspections of champion speed typists, who report that they seldom recall the meaning from the source material incidentally.

— William E. Cooper, Cognitive Aspects of Skilled Typewriting, 2012

We don’t even know the keyboard. A 2013 study at Vanderbilt asked 100 subjects to take a short typing test; they were then shown a blank QWERTY keyboard and given 80 seconds to label the keys. On average they typed at 72 words per minute with 94 percent accuracy but could correctly label only 15 letters on a blank keyboard.

“This demonstrates that we’re capable of doing extremely complicated things without knowing explicitly what we are doing,” said graduate student Kristy Snyder.

It had formerly been believed that typing starts as a conscious process that becomes unconscious with repetition. But it appears that typists never memorize the key locations in the first place.

“It appears that not only don’t we know much about what we are doing, but we can’t know it because we don’t consciously learn how to do it in the first place,” said psychologist Gordon Logan.

(Kristy M. Snyder et al., “What Skilled Typists Don’t Know About the QWERTY Keyboard,” Attention, Perception, & Psychophysics 76:1 [January 2014], 162-171.)

Tight Squeeze

Above: From Paris, 1927: a novelty car that can “sidle” into parking spaces.

Below: Someone was actually working on this in the 1950s (thanks, Martin):

A related puzzle from The Chicken From Minsk, Yuri B. Chernyak’s 1995 collection of math and physics problems: Why is it easier to parallel-park a (conventional) car by backing into the space rather than pulling in directly?

Click for Answer

Helping Hand
Image: Flickr

This Victorian artificial arm and hand is in the collection of the London Science Museum. “The arm is amazingly versatile,” writes Ben Russell in Robots (2017). “The elbow can be locked in several positions, and the fingers articulated using a brass button in the wrist. It is also heavily decorated in the neo-Gothic style. Rather than being covered up, this arm would be out on view, making its wearer a true man-machine.”
Image: Flickr

A Catalog of Clever Expedients

Henry T. Brown’s 1868 mechanical encyclopedia Five Hundred and Seven Mechanical Movements is being animated on this fascinating site — see working demonstrations of hundreds of mechanical linkages from the age of steam.

Note that it’s a work in progress — the movements that have been animated are indicated with colored thumbnails. Owner Matt Keveney plans eventually to animate all 507 movements in Brown’s original text.

(Thanks, Sharon.)

Crowd Control

Tokyo has the world’s busiest train stations, handling 13 billion passenger trips a year. To keep things running smoothly it relies on some subtle features to manipulate passenger behavior.

Blue lights mounted discreetly at either end of a platform, the points at which prospective suicides contemplate leaping into the path of oncoming trains, have been associated with an 84 percent decline in such attempts.

Rail operator JR East commissioned composer Hiroaki Ide to replace the grating buzzer that used to signal a train’s departure with short, pleasant jingles known as hassha melodies. These have produced a 25 percent reduction in passenger injuries due to rushing.

Stations also disperse young people by playing 17-kilohertz tones that can generally only be heard by those under 25. And rail employees are trained to use the “point and call” method, shisa kanko, in executing tasks. Physically pointing at an object and verbalizing one’s intentions has been shown to reduce human error by as much as 85 percent.

(Thanks, Sharon.)

Ellison Words
Image: Wikimedia Commons

Science fiction writer Harlan Ellison typed more than 1,700 works using a single finger of each hand. In 1999 Mike Keith set out to learn which words would be easiest for him to type. “Easy” means that successive letters are typed by alternate hands and that the hands travel as little as possible. (See the article for some other technicalities.)

Here are the easiest words of 4 to 13 letters; the score in parenthesis is the total linear distance traveled by the fingers, normalized by dividing by the length of the word (lower is better):

BANANA (0.17)
AUSTERE (0.77)

Ellison could easily have used most of these in a story about an infectious disease outbreak in India. But I guess that might have looked lazy.

(Michael Keith, “Typewriter Words,” Word Ways 32:4 [November 1999], 270-277.)