with numbers printed on them from 1 upwards in numerical order. The idea
suddenly came to me, as ideas have a way of unexpectedly coming, to make
a little puzzle of this. I wonder whether many readers will arrive at
the same solution that I did.

Take seven strips of cardboard and lay them together as above. Then
write on each of them the numbers 1, 2, 3, 4, 5, 6, 7, as shown, so that
the numbers shall form seven rows and seven columns.

Now, the puzzle is to cut these strips into the fewest possible pieces
so that they may be placed together and form a magic square, the seven
rows, seven columns, and two diagonals adding up the same number. No
figures may be turned upside down or placed on their sides--that is, all
the strips must lie in their original direction.

Of course you could cut each strip into seven separate pieces, each
piece containing a number, and the puzzle would then be very easy, but I
need hardly say that forty-nine pieces is a long way from being the
fewest possible.


401.--EIGHT JOLLY GAOL BIRDS.

[Illustration]

The illustration shows the plan of a prison of nine cells all
communicating with one another by doorways. The eight prisoners have
their numbers on their backs, and any one of them is allowed to exercise
himself in whichever cell may happen to be vacant, subject to the rule
that at no time shall two prisoners be in the same cell. The merry