Clever calculation has established a fact which we shall not be able to verify by personal experience. Whatever else may happen, the first day of a century can never fall on Sunday, Wednesday, or Friday.
No. CXI.—SQUARES ON THE CROSS
On this cross there are seventeen distinct and perfect squares marked out at their corners by asterisks.
How few, and which, of these can you remove, so that not a single perfect square remains?
STANDING ROOM FOR ALL
On a globe 2 feet in diameter the Dead Sea appears but as a small coloured dot. If it were frozen over there would be standing room on its surface for the whole human race, allowing 6 square feet for each person; and if they were all suddenly engulfed, it would merely raise the level of the lake about 4 inches.
No. CXII.—A CHINESE PUZZLE
Here is quite a good exercise for ingenious brains and fingers. Cut a piece of stiff paper or cardboard into such a right-angled triangle as is shown below.