No doubt some of my readers will smile at the statement that a man in a
boat on smooth water can pull himself across with the tiller rope! But it
is a fact. If the jester had fastened the end of his rope to the stern of
the boat and then, while standing in the bows, had given a series of
violent jerks, the boat would have been propelled forward. This has often
been put to a practical test, and it is said that a speed of two or three
miles an hour may be attained. See W. W. Rouse Ball's _Mathematical
Recreations_.