The Insurance Act is a most prolific source of entertaining puzzles,
particularly entertaining if you happen to be among the exempt. One's
initiation into the gentle art of stamp-licking suggests the following
little poser: If you have a card divided into sixteen spaces (4 × 4),
and are provided with plenty of stamps of the values 1d., 2d., 3d., 4d.,
and 5d., what is the greatest value that you can stick on the card if
the Chancellor of the Exchequer forbids you to place any stamp in a
straight line (that is, horizontally, vertically, or diagonally) with
another stamp of similar value? Of course, only one stamp can be affixed
in a space. The reader will probably find, when he sees the solution,
that, like the stamps themselves, he is licked He will most likely be
twopence short of the maximum. A friend asked the Post Office how it was
to be done; but they sent him to the Customs and Excise officer, who
sent him to the Insurance Commissioners, who sent him to an approved
society, who profanely sent him--but no matter.