Frank noted that the boat floated well on the water. It was light, and with one passenger could easily be propelled, so as to make swift time.
"I'll have the current with me going," the boy thought, as he noted that the stream ran in a general direction toward the sanitarium. "I'll have to paddle back against it. Of course maybe this is not the same creek or river that flows past the cliff, and there may be falls or rapids in it that I can't take the boat through. But it will do no harm to try."
He was all impatience for his companions to go to bed. Fortunately for him they were tired out with the day's labor on the canoe. They prepared an early supper, and, after talking a while around the campfire, discussing what they would do, now that they had a boat, the boys went to their cots.
Frank's bed was nearest the back wall of the tent, and he was glad of this, as it would make his exit easier. He thought his chums would never go to sleep, but at length their heavy and regular breathing told him they were slumbering.
Cautiously he gathered his clothes in a bundle and shoved them out under the tent. He had, unknown to his companions, made up a package of food, as he did not want to get caught again with nothing to eat. Making no noise, he crawled under the tent, as he had done before. He looked at his watch. It was a little after ten o'clock. He hurriedly dressed outside the tent, and then, securing the paddle, he made his way to where the canoe floated in the creek.
It was a bright moonlight night, warm, calm and still. Frank felt just a little uneasiness as he stepped into the boat and shoved off. It was rather a queer thing to do, he thought, and he wondered what his chums would say if they saw him. But, he reflected, it was important to him to solve the secret which bothered him so greatly.
Paddling cautiously, Frank sent the frail craft out into the middle of the stream. There was not much current, but what there was helped him along. He urged the boat forward more rapidly as he left the camp behind, and soon he was half a mile on his strange night journey.
Only for the light draught of the boat Frank would never have been able to get along. Even drawing but a few inches, the canoe several times touched sand bars over which it glided. Frank did not know the channel, and he had to trust to luck. But, as he went on he noticed that the stream was becoming wider and deeper, and he had no fear but that he might continue on for many miles.
"If only it goes in the right direction," he murmured. "It may be an altogether different creek than this which flows past the cliff. If it is I've had all my trouble for nothing. I want to get back before the boys wake up, if I can."
On and on he went. The moon threw fantastic shadows through the trees to the surface of the stream. Now the boat would glide along in the darkness, caused by the overhanging branches, and again it would forge ahead into a bright patch of silvery light.