“Poor Bob,” said Ned with a sigh. “I wish you hadn’t eaten that strange fruit.”
As the afternoon wore away Ned listened anxiously for the sound of Jerry’s returning footsteps. For want of something better to do to while away the time he began cleaning the engine of the Dartaway.
It was while doing this that he happened to look at the edge of the lake. Something queer about it attracted his attention.
“If I didn’t know differently,” he said to himself, “I’d say the tide was falling. It looks just as if the water was lower.”
Feeling sure that such a thing was impossible, Ned went on working at the engine. A little later he again gazed over the side of the boat. This time he started in surprise.
“I’m positive that stone wasn’t so far out of water the last time I looked,” he said, speaking aloud. “I wonder if this lake can be connected with the ocean in some manner, and is affected by the tide? No, it can’t be, or we’d have noticed it before. Yet the water is surely running away.”
He got out of the Dartaway. He was much alarmed to see that nearly half of the craft was now out of the lake, whereas a while before only the bow-end had rested on the sandy beach.
“The lake is surely lowering,” Ned went on. “I must watch and see how fast it is falling.”
He marked where the water came on shore and sat down to wait. He was too much worried to be able to go on working. Bob called, and he went in to see what was wanted. He gave his chum a drink and administered some more medicine. He was in the tent a half hour, and when he came out he was surprised to see that the water was half an inch from the mark.
“It’s falling at the rate of an inch an hour,” said Ned. “This is getting serious. I wish Jerry and the professor would come back.”