see now, and the thing appears obvious enough when one has heard
the explanation. But it is really rather odd that no one should have
passed through this gap for days, and then that four persons should have
come here within quite a short interval of one another."

"What makes you think they have done so?" Thorndyke asked.

"Well," I replied, "both of these sets of footprints appear to be quite
fresh, and to have been made about the same time."

"Not at the same time, Jervis," rejoined Thorndyke. "There is certainly
an interval of several hours between them, though precisely how many
hours we cannot judge, since there has been so little wind lately to
disturb them; but the fisherman unquestionably passed here not more than
three hours ago, and I should say probably within an hour; whereas the
other man--who seems to have come up from a boat to fetch something of
considerable weight--returned through the gap certainly not less, and
probably more, than four hours ago."

I gazed at my friend in blank astonishment, for these events befell in
the days before I had joined him as his assistant, and his special
knowledge and powers of inference were not then fully appreciated by me.

"It is clear, Thorndyke," I said, "that footprints have a very different
meaning to you from what they have for me. I don't see in the least how
you have reached any of these conclusions."

"I suppose not," was the reply; "but, you see, special knowledge of this
kind is the stock-in-trade of the medical jurist, and has to be acquired
by special study, though the present example is one of the greatest
simplicity. But let us consider it point by point; and first we will
take this set of footprints which I have inferred to be a fisherman's.
Note their enormous size. They should be the footprints of a giant. But
the length of the stride shows that they were made by a rather short
man. Then observe the massiveness of the soles, and the fact that there
are no nails in them. Note also the peculiar clumsy tread--the deep toe
and heel marks, as if the walker had wooden legs, or fixed ankles and
knees. From that character we can safely infer high boots of thick,
rigid leather, so that we can diagnose high boots, massive and stiff,
with nailless soles, and many sizes too large for the wearer. But the
only boot that answers this description is the fisherman's
thigh-boot--made of enormous size to enable him to wear in the winter
two or three pairs of thick