Extending down the middle of the craft was something which looked like a long box, open at the top. The lower side of the box was covered with glass. Passengers on the seats could look into the box, through the glass bottom, and see objects on the ocean's bed with wonderful clearness. A man up near the prow did the rowing.
"I claim," said the runner, "that this here's the only kind of a boat to use in seein' the marine gardens. We can go places in these little boats that they can't get, to in the big ones."
That must have been a particularly slack day for the glass-bottom boats, for Clancy and Hill were the only passengers on this particular craft.
"I reckon that's all, Ike," said the man who had brought the two youths to the boat: "let 'er go!"
Ike proceeded to use the oars, and, while the boat rounded the end of the pier, Hiram hung to his seat with both hands, and looked wildly and expectantly at Clancy.
"Beginnin' to feel squeamish," mumbled Hiram.
"Don't think about it," returned the motor wizard. "Look down at the marine gardens, Hiram."
Hill gradually forgot his uneasiness. There was hardly any motion to the boat, save a slow, steady gliding onward. Off Avalon there is no surf, the tides rise and fall, as on the mainland, but the sea is usually as quiet as the waters of a pond.
There were other glass-bottom boats out that afternoon, and they were scattered just off shore to Sugarloaf Rock and beyond. Not far from the towering Rock were two or three rowboats, each manned by an oarsman, and carrying a man in a bathing suit.
"Them's divers," explained Ike, nodding to the men in the bathing suits. "Didn't you see 'em when your boat come in?"