whole subject is capable of really systematic and scientific treatment.
In the main the data are anatomical, but age, sex, occupation, health,
and disease all give their various indications. Clearly, for instance,
the footprints of an old man will differ from those of a young man of
the same height, and I need not point out to you that those of a person
suffering from locomotor ataxia or paralysis agitans would be quite
unmistakable."

"Yes, I see that plainly enough," I said.

"Here, now," he continued, "is a case in point." He halted to point with
his stick at a row of footprints that appeared suddenly above high-water
mark, and having proceeded a short distance, crossed the line again, and
vanished where the waves had washed over them. They were easily
distinguished from any of the others by the clear impressions of
circular rubber heels.

"Do you see anything remarkable about them?" he asked.

"I notice that they are considerably deeper than our own," I answered.

"Yes, and the boots are about the same size as ours, whereas the stride
is considerably shorter--quite a short stride, in fact. Now there is a
pretty constant ratio between the length of the foot and the length of
the leg, between the length of leg and the height of the person, and
between the stature and the length of stride. A long foot means a long
leg, a tall man, and a long stride. But here we have a long foot and a
short stride. What do you make of that?" He laid down his stick--a
smooth partridge cane, one side of which was marked by small lines into
inches and feet--beside the footprints to demonstrate the discrepancy.