INTRODUCTION
Then if you give a " crossing the river " puzzle, in which people
have to be got over in a boat that will only hold a certain number
or combination of persons, directly the would-be solver fails to
master the difficulty he boldly introduces a rope to pull the boat
across. You say that a rope is forbidden ; and he then falls back
on the use of a current in the stream. I once thought I had
carefully excluded all such tricks in a particular puzzle of this class.
But a sapient reader made all the people swim across without using
the boat at all! Of course, some few puzzles are intended to be
solved by some trick of this kind ; and if there happens to be no
solution without the trick it is perfectly legitimate. We have
to use our best judgment as to whether a puzzle contains a
catch or not; but we should never hastily assume it. To quibble
over the conditions is the last resort of the defeated would-be
solver.
Sometimes people will attempt to bewilder you by curious little
twists in the meaning of words. A man recently propounded to
me the old familiar problem, "A boy walks round a pole on
which is a monkey, but as the boy walks the monkey turns on the
pole so as to be always facing him on the opposite side. Does the
boy go around the monkey ? " I replied that if he would first give
me his definition of "to go around" I would supply him with the
answer. Of course, he demurred, so that he might catch me either
way. I, therefore, said that, taking the words in their ordinary
and correct meaning, most certainly the boy went around the
monkey. As was expected, he retorted that it was not so, because
he understood by "going around" a thing that you went in
such a way as to see all sides of it. To this I made the
obvious reply that consequently a blind man could not go around
anything.
He then amended his definition by saying that the actual seeing
all sides was not essential, but you went in such a way that, given
xx
