A Feathered Maître d’

The greater honeyguide of Africa eats beeswax but isn’t always able to invade a hive on its own. So it has forged a unique partnership with human beings: The bird attracts the attention of local honey hunters with a chattering call, flies toward a hive, then stops and calls again. When they arrive at the hive, the humans open it, subdue the bees with smoke, take the honey, and leave the wax for the bird.

This arrangement saves the humans an average of 5.7 hours in searching for hives, but it’s not foolproof. “We have been ‘guided’ to an abrupt precipice and to a bull elephant by greater honeyguides,” report biologists Lester Short and Jennifer Horne. “In these cases there were bee-hives below the cliff (in a valley) and beyond the elephant. Concern for the welfare of the guided person is beyond any reasonable expectation of a honeyguide.”

(Thanks, Tom.)

| Science & Math

Reality Unperceived

http://commons.wikimedia.org/wiki/File:Skarbina_Parkweiher_Partie_im_Tiergarten.jpg

But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park, or books existing in a closet, and nobody by to perceive them. I answer, you may so, there is no difficulty in it; but what is all this, I beseech you, more than framing in your mind certain ideas which you call books and trees, and the same time omitting to frame the idea of any one that may perceive them? But do not you yourself perceive or think of them all the while? This therefore is nothing to the purpose; it only shews you have the power of imagining or forming ideas in your mind: but it does not shew that you can conceive it possible the objects of your thought may exist without the mind.

— George Berkeley, A Treatise Concerning the Principles of Human Knowledge, 1710

| Science & Math

The Blank Column

A printer prints a sentence in a monospaced font. It inserts a space after the concluding period and then prints the same sentence again. It continues in this way until it has filled the page, running the sentences together into one long paragraph. The sentence is shorter than a full line, and no words are hyphenated. Prove that the finished page will always include a full column of blank spaces.

Click for Answer
| Puzzles

The Mechanical Internet

http://commons.wikimedia.org/wiki/File:Télégraphe_Chappe_2.jpg

Telecommunications got an early start in France, where inventor Claude Chappe built a series of towers between Lille and Paris in 1792. Each tower was topped with a set of movable wooden arms that could be arranged to represent symbols; if each operator viewed his neighbor through a telescope, a symbol could pass through 15 stations covering 120 miles in only 9 minutes, giving France a valuable communications advantage over the surrounding powers during the sensitive period of the revolution. It makes an appearance in The Count of Monte Cristo:

They passed to the third story; it was the telegraph room. Monte Cristo looked in turn at the two iron handles by which the machine was worked. ‘It is very interesting,’ he said, ‘but it must be very tedious for a lifetime.’

‘Yes. At first my neck was cramped with looking at it, but at the end of a year I became used to it; and then we have our hours of recreation, and our holidays.’

‘Holidays?’

‘Yes.’

‘When?’

‘When we have a fog.’

Expanded into a network of 534 stations, the system worked well, but it was expensive, with skilled operators manning towers set every 10-30 kilometers, and the messages were far from private. Finally the electrical telegraph killed it — Sweden abandoned the last commercial semaphore line in 1880. By then, depressed by illness and the conviction that others were stealing his ideas, Chappe had long since killed himself.

| Technology

Straw Poll

A groaner from Clark Kinnaird’s Encyclopedia of Puzzles and Pastimes (1946):

“A farmer had 3 3/7 haystacks in one field and 5 4/9 haystacks in another field. He put them all together. How many did he have then?”

I’ll withhold the answer.

| Puzzles

Holy Smokes

On Sept. 13, 1862, members of the 27th Indiana Infantry were awaiting orders on a hillside near Frederick, Md., as Robert E. Lee’s Confederate troops approached from the south. One of the men noticed a package on the ground and discovered three cigars wrapped in a piece of paper. The men were rejoicing in their good fortune when a sergeant noticed writing on the paper — it was headed “Headquarters of the Army of Northern Virginia.”

They had discovered Lee’s battle plan. The orders had been issued to Gen. D.H. Hill, but one of his staff officers had apparently dropped them; Hill received a second copy from Stonewall Jackson and had not realized that the first set had been lost.

The plans passed quickly up the line, and that afternoon Union general George C. McClellan was wiring the president, “I have all the plans of the rebels, and will catch them in their own trap.” The battle of Sept. 17, Antietam, was the bloodiest single day of the Civil War. It repelled the rebel army and permitted Lincoln to issue the Emancipation Proclamation from a position of strength.

Lee later told a friend: “I went into Maryland to give battle, and could I have kept Gen. McClellan in ignorance of my position and plans a day or two longer, I would have fought and crushed him.”

| History

Social Studies

http://www.google.com/patents/about?id=WPMEAAAAEBAJ&dq=6170379

Galvanized by the school shootings of the late 1990s, James R. Taylor patented a desk whose top doubles as a bullet-resistant shield:

“Another object is to provide a shield that is configured to function normally in an innocuous mode as an ordinary desk work surface but that can be easily and quickly removed from the desk for use as a personal shield against projectiles including but not limited to bullets, knives, shrapnel, or flying debris that might be encountered in naturally occurring events such as earthquakes, fires, or storms.”

I can’t tell whether any districts adopted it. Hopefully we’ll never find out.

| Society · Technology

Getting Behind

In London some years ago a man named Pierce Bottom, weary of jokes about his name, spent several days combing through the telephone directories, seeking people who had ‘bottom’ in their names. He found dozens — Bottom, Bottomley, Winterbottom, Throttlebottom, Greenbottom, Sidebottom, Higginbottom, and so on. He arranged for a dinner to be served in the sub-basement of a London building, and sent engraved invitations to all the ‘bottoms.’ Most of them showed up, but Pierce Bottom did not, and the guests found that each of them had to pay his own check. The entree was rump roast.

— H. Allen Smith, The Compleat Practical Joker, 1953

| Hoaxes