I'll soon know." Tom had, among his tackle, a line with a sinker attached.

He tossed the sinker over the side of the canoe, paying out the line until the sinker touched bottom.

Then he pulled the line in again, carefully measuring by his arm as much of the line as was wet.
"Danny," he announced solemnly, "at this point the water is from twenty-seven to thirty feet deep." "Then that man did drown!" breathed Dalzell, his face as white as chalk.
"Of course he did," Tom agreed, "provided he was alive when we saw him." "But he had to be alive," protested Dan, "or else he couldn't have nailed the framework together and decorated it with branches from bushes." "That is, if the man we saw made the frame," propounded Reade in a very solemn voice.
It was a shock to both of them.

The whole incident had been uncanny and unreal, but the horror of that haggard, haunting face was still strong upon both of the beholders.
"Tom, we simply must get off our clothes and dive to see what we can do to find that poor fellow," urged Dalzell.
"All right," assented Reade.

"I'll do all the diving myself, Danny, if you'll take command and give your orders.