should remain stationary
during his pleasure. He then proposed to draw three circles inside the
large one, so that no cat could approach another cat without crossing a
magic circle. Try to draw the three circles so that every cat has its
own enclosure and cannot reach another cat without crossing a line.

168.--THE CHRISTMAS PUDDING.

[Illustration]

"Speaking of Christmas puddings," said the host, as he glanced at the
imposing delicacy at the other end of the table. "I am reminded of the
fact that a friend gave me a new puzzle the other day respecting one.
Here it is," he added, diving into his breast pocket.

"'Problem: To find the contents,' I suppose," said the Eton boy.

"No; the proof of that is in the eating. I will read you the
conditions."

"'Cut the pudding into two parts, each of exactly the same size and
shape, without touching any of the plums. The pudding is to be regarded
as a flat disc, not as a sphere.'"

"Why should you regard a Christmas pudding as a disc? And why should any
reasonable person ever wish to make such an accurate division?" asked
the cynic.

"It is just a puzzle--a problem in dissection." All in turn had a look
at the puzzle, but nobody succeeded in solving it. It is a little
difficult unless you are acquainted with the principle involved in the
making of such puddings, but easy enough when you know how it is done.

169.--A TANGRAM PARADOX.

Many pastimes of great antiquity, such as chess, have so developed and
changed down the centuries that their original inventors would scarcely
recognize them. This is not the case with Tangrams, a recreation that
appears to be at least four thousand years old, that has apparently
never been dormant, and that has not been altered or "improved upon"
since the legendary Chinaman Tan first cut out the seven pieces shown in
Diagram I. If you mark the point B, midway between A and C, on one side
of a square of any size, and D, midway between C and E, on an adjoining
side, the direction of the cuts is too obvious to need further
explanation. Every design in this article is built up from the seven
pieces of blackened cardboard. It will at once be understood that the
possible combinations are infinite.

[Illustration]

The late Mr. Sam Loyd, of New York, who published a small book of very
ingenious designs, possessed the manuscripts of the late Mr. Challenor,
who made a long and close study of Tangrams. This gentleman, it is said,
records