I was too obtuse to take in.

All night Tom Donahue was greatly excited, and when Wharton left
he begged him to remember his promise, and also elicited from him a
description of the exact spot at which he had seen the apparition, as
well as the hour at which it appeared. After his departure, which must
have been about four in the morning, I turned into my bunk and watched
Tom sitting by the fire splicing two sticks together, until I fell
asleep. I suppose I must have slept about two hours; but when I awoke
Tom was still sitting working away in almost the same position. He had
fixed the one stick across the top of the other so as to form a rough T,
and was now busy in fitting a smaller stick into the angle between
them, by manipulating which, the cross one could be either cocked up or
depressed to any extent. He had cut notches, too, in the perpendicular
stick, so that, by the aid of the small prop, the cross one could be
kept in any position for an indefinite time.

"Look here, Jack!" he cried, when he saw that I was awake. "Come and
give me your opinion. Suppose I put this cross-stick pointing straight
at a thing, and arranged this small one so as to keep it so, and left
it, I could find that thing again if I wanted it--don't you think I
could, Jack--don't you think so?" he continued, nervously, clutching me
by the arm.

"Well," I answered, "it would depend on how far off the thing was, and
how accurately it was pointed. If it were any distance, I'd cut sights
on your cross-stick; then a string tied to the end of it, and held in
a plumb-line forward, would lend you pretty near what you wanted. But
surely, Tom, you don't intend to localise the ghost in that way?"