“That same night,” Thorndyke resumed, “I cycled down to the shore, through the Gap, with a supply of plaster of Paris, and proceeded to take plaster moulds of the more important of the footprints.” (Here the magistrates, the inspector, and Mr. Bashfield with one accord sat up at attention; Sergeant Payne swore quite audibly; and I experienced a sudden illumination respecting a certain basin and kitchen spoon which had so puzzled me on the night of Thorndyke’s arrival.) “As I thought that liquid plaster might confuse or even obliterate the prints in sand, I filled up the respective footprints with dry plaster, pressed it down lightly, and then cautiously poured water on to it.  The moulds, which are excellent impressions, of course show the appearance of the boots which made the footprints, and from these moulds I have prepared casts which reproduce the footprints themselves.

“The first mould that I made was that of one of the tracks from the boat up to the Gap, and of this I shall speak presently.  I next made a mould of one of the footprints which have been described as those of the deceased.”

“Have been described!” exclaimed the chairman.  “The deceased was certainly there, and there were no other footprints, so, if they were not his, he must have flown to where he was found.”

“I will call them the footprints of the deceased,” replied Thorndyke imperturbably.  “I took a mould of one of them, and with it, on the same mould, one of my own footprints.  Here is the mould, and here is a cast from it.” (He turned and took them from the triumphant Polton, who had tenderly lifted them out of the trunk in readiness.) “On looking at the cast, it will be seen that the appearances are not such as would be expected.  The deceased was five feet nine inches high, but was very thin and light, weighing only nine stone six pounds, as I ascertained by weighing the body, whereas I am five feet eleven and weigh nearly thirteen stone.  But yet the footprint of the deceased is nearly twice as deep as mine—­that is to say, the lighter man has sunk into the sand nearly twice as deeply as the heavier man.”

The magistrates were now deeply attentive.  They were no longer simply listening to the despised utterances of a mere scientific expert.  The cast lay before them with the two footprints side by side; the evidence appealed to their own senses and was proportionately convincing.

“This is very singular,” said the chairman; “but perhaps you can explain the discrepancy?”

“I think I can,” replied Thorndyke; “but I should prefer to place all the facts before you first.”

“Undoubtedly that would be better,” the chairman agreed.  “Pray proceed.”

“There was another remarkable peculiarity about these footprints,” Thorndyke continued, “and that was their distance apart—­the length of the stride, in fact.  I measured the steps carefully from heel to heel, and found them only nineteen and a half inches.  But a man of Hearn’s height would have an ordinary stride of about thirty-six inches—­more if he was walking fast.  Walking with a stride of nineteen and a half inches he would look as if his legs were tied together.