“The general appearance of the body,” said Thorndyke, when he had noted these particulars, “suggests death by drowning, though, of course, we can’t give a definite opinion until a post mortem has been made.”
“You don’t attach any significance to that scalp-wound, then?” I asked.
“As a cause of death? No. It was obviously inflicted during life, but it seems to have been an oblique blow that spent its force on the scalp, leaving the skull uninjured. But it is very significant in another way.”
“In what way?” I asked.
Thorndyke took out his pocket-case and extracted a pair of forceps. “Consider the circumstances,” said he. “This man put off from the shore to go to the lighthouse, but never arrived there. The question is, where did he arrive?” As he spoke he stooped over the corpse and turned back the hair round the wound with the beak of the forceps. “Look at those white objects among the hair, Jervis, and inside the wound. They tell us something, I think.”
I examined, through my lens, the chalky fragments to which he pointed. “These seem to be bits of shells and the tubes of some marine worm,” I said.
“Yes,” he answered; “the broken shells are evidently those of the acorn barnacle, and the other fragments are mostly pieces of the tubes of the common serpula. The inference that these objects suggest is an important one. It is that this wound was produced by some body encrusted by acorn barnacles and serpulæ; that is to say, by a body that is periodically submerged. Now, what can that body be, and how can the deceased have knocked his head against it?”
“It might be the stem of a ship that ran him down,” I suggested.
“I don’t think you would find many serpulæ on the stem of a ship,” said Thorndyke. “The combination rather suggests some stationary object between tidemarks, such as a beacon. But one doesn’t see how a man could knock his head against a beacon, while, on the other hand, there are no other stationary objects out in the estuary to knock against except buoys, and a buoy presents a flat surface that could hardly have produced this wound. By the way, we may as well see what there is in his pockets, though it is not likely that robbery had anything to do with his death.”
“No,” I agreed, “and I see his watch is in his pocket; quite a good silver one,” I added, taking it out. “It has stopped at 12.13.”