The point of this puzzle turns on the fact that if the magic square were
to be composed of whole numbers adding up 15 in all ways, the two must be
placed in one of the corners. Otherwise fractions must be used, and these
are supplied in the puzzle by the employment of sixpences and
half-crowns. I give the arrangement requiring the fewest possible current
English coins--fifteen. It will be seen that the amount in each corner is
a fractional one, the sum required in the total being a whole number of
shillings.
[Illustration]