During a Nelson celebration I was standing in Trafalgar Square with a
friend of puzzling proclivities. He had for some time been gazing at the
column in an abstracted way, and seemed quite unconscious of the casual
remarks that I addressed to him.

"What are you dreaming about?" I said at last.

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"Two feet----" he murmured.

"Somebody's Trilbys?" I inquired.

"Five times round----"

"Two feet, five times round! What on earth are you saying?"

"Wait a minute," he said, beginning to figure something out on the back
of an envelope. I now detected that he was in the throes of producing a
new problem of some sort, for I well knew his methods of working at these
things.

"Here you are!" he suddenly exclaimed. "That's it! A very interesting
little puzzle. The height of the shaft of the Nelson column being 200
feet and its circumference 16 feet 8 inches, it is wreathed in a spiral
garland which passes round it exactly five times. What is the length of
the garland? It looks rather difficult, but is really remarkably easy."

He was right. The puzzle is quite easy if properly attacked. Of course
the height and circumference are not correct, but chosen for the purposes
of the puzzle. The artist has also intentionally drawn the cylindrical
shaft of the column of equal circumference throughout. If it were
tapering, the puzzle would be less easy.

99.--_The Two Errand Boys._

A country baker sent off his boy with a message to the butcher in the
next village, and at the same time the butcher sent his boy to the baker.
One ran faster than the other, and they were seen to pass at a spot 720
yards from the baker's shop. Each stopped ten minutes at his destination
and then started on the return journey, when it was found that they
passed each other at a spot 400 yards from the butcher's. How far apart
are the two tradesmen's shops? Of course each boy went at a uniform pace
throughout.

100.--_On the Ramsgate Sands._

Thirteen youngsters were seen dancing in a ring on the Ramsgate sands.
Apparently they were playing "Round the Mulberry Bush." The puzzle is
this. How many rings may they form without any child ever taking twice
the hand of any other child--right hand or left? That is, no child may
ever have a second time the same neighbour.

101.--_The Three Motor-Cars._

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Pope has told us that all chance is but "direction which thou canst not
see," and certainly we all occ