Choose a number on this clock face and, starting from 12, spell out that number’s English name as you advance clockwise around the face, one letter per numeral. For example, if you’ve chosen 3, count out T-H-R-E-E and you’ll land on the numeral 5. Adopt this new position as your next chosen number and proceed as before (in this case, counting F-I-V-E and landing on 9). After three or more moves you’ll reliably land on 1.

This works because of a characteristic of Markov chains first observed by Russian mathematician Evgenii Borisovich Dynkin. Here’s a card trick that exploits the same principle.

This recording presents four pairs of tones, each pair separated by three whole tones, or half an octave. Curiously, some listeners hear the interval as ascending, others as descending. (In fact the tones used are ambiguous as to octave, so there’s no objectively right answer.)

Even more curiously, sometimes a listener’s perception reverses when an interval is transposed, say from C-F# to G#-D, even though nothing else has changed.

Diana Deutsch discovered the effect in 1986.

Age, if healthy, happy
Ancestors, their examples should excite to great and virtuous actions
Animals, a degree of gratitude owing to them that serve us
Atheist, behaviour of one in sickness
Barbers, inconveniences attending their being historians
Classics, absolutely necessary to study them
Climate, British, very inconstant
Cowards never forgive
Cunning opposed to wisdom
Duels, the danger of dying in one, represented
Earth, its inhabitants ranged under two general heads
Examination, self, advantages attending it
Fame, common, house of, described
Feet, pretty ones, a letter concerning them
Flies and free-thinkers compared
Gardens, the best not so fine as nature
Honour, temple of, can be entered only through that of Virtue
Horse, described by Homer, Virgil, Oppian, Lucan, and Pope
Janglings, matrimonial
Ladies, all women such
Laughter, the chorus of conversation
Master, how he should behave to his servants
Pedants, their veneration for Greek and Latin condemned
Peruke, a kind of index to the mind
Possession, true, consists in enjoyment
Reproof distinguished from reproach
Sloth more invincible than vice
Terrible Club, account of it
Time not to be squandered
Wisdom opposed to cunning
Women should have learning

Henry Wheatley said that the indexes “possess that admirable quality of making the consulter wish to read the book itself.” Leigh Hunt wrote, “As there is ‘a soul of goodness in things evil’ so there is a soul of humor in things dry … so an Index, like the Tatler’s, often gives us a taste of the quintessence of his humor.”

From Henry Dudeney:

“The illustration represents a map (considerably simplified for our purpose) of a certain district on the Continent. The circles are towns and the lines roads. During the war five regiments marched to new positions on the same night. The body stationed at the upper A marched to the lower A, that at the upper B to the lower B, that at the upper C to the lower C, that at the upper D to the lower D, and the regiment at the left-hand E marched to the right-hand E. Yet no regiment ever saw anything of any other regiment. Can you mark out the route taken by each so that no two regiments ever go along the same road anywhere?”

“It can be really bizarre if, when I’ve been alone for several hours, I spot a human standing or walking in the distance. For an instant, my reaction is, ‘What the hell is that?’ A large mammal that walks on its hind legs seems very strange.”

clocks to Algeria
fur to Australia
flypaper to Botswana
playing cards to Brazil
bicycles to China
leeches to Cyprus
absinthe to Germany
gardenias to Guatemala
bees to Iceland
fashion newspapers to Iran
fireworks to Ireland
sand to Israel
nutmeg to Italy
hoverboards to Japan
deer antlers to Kazakhstan
tea to Libya
cinnamon to Nepal
keys to New Zealand
pastries to Panama
vitamins to Peru
aspirin to Tunisia
eggs to Turkmenistan
honey to Zimbabwe

It’s illegal to send “daggers, sword-canes, brass knuckles, blackjacks, and other secret weapons” to Cote d’Ivoire.

Comfort had enlisted in the Continental Army as a teenager. According to the Boston Post, “Wheeler recollected many things he had been told by his father regarding the war of ’75. Many times Constant said his father spoke of meeting George Washington and he admired General Putnam, whose bluff, hearty way he often mentioned.”

William was himself a veteran of the Civil War. According to FindAGrave, he died in 1941 at age 93.

(Thanks, Bevan. Here’s a photo [!] of a man who crossed the Delaware with Washington.)

In the illuminated manuscripts of the 13th and 14th centuries, the margins are often decorated with images of armed knights fighting snails. “This has created a good deal of puzzlement amongst art historians and book historians, wondering just what do they mean?” University of York scholar Kenneth Clarke told the BBC.

“The basic idea is the overturning of existing or expected hierarchies,” suggested University of Chicago art historian Marian Bleeke. “It is supposed to be surprising and even funny — I think we get that implicitly today,” she says. Art historian Lilian Randall found 70 examples in 29 books, most printed between 1290 and 1310, commonly in France.

Perhaps the fight represents a struggle between classes, or illustrates cowardice. Possibly it’s political comment whose meaning has been lost. It may even represent the Resurrection. The meaning is still a matter of debate.

The British Library has a gallery.

(Thanks, Carsten.)

Hand bathed with tears                     27
I could only weep                          48
Tears, wrung from the heart                51
Tear stood in eye                          65
Dropped one tear, no more                  67
Tears, press-gang could scarce keep from   69
Big drops wetted gray beard                70
Moistened eye                              72
Girl wept, brother sobbed                  74
Tears gushed afresh                        75
Tears flowing without control              96

And so on. At the top he notes, “Choking, &c, not counted.”

Can you join the dots in this grid to form a continuous loop that never crosses or touches itself? Only horizontal and vertical lines between dots are allowed. Some of the connections have already been made, as a start.

	SelectClick for Answer
From the WikiBooks puzzles collection.