"Why don't they stop?" wailed Grace. "Then we wouldn't bump them so hard!"
As if in answer, there came echoing over the dark water the clang of the engine-room bell, that told half-speed ahead had been ordered. A moment later came the signal to stop the engines.
"Oh, if only Uncle Amos—or some of the boys—were here!" breathed Betty. "Girls, try once more!"
Together Mollie and Grace whirled the crank, and an instant later the motor started with a throb that shook the boat from stem to stern.
"There!" cried Betty. "Now I can avoid them."
She threw in the clutch, and as the Gem shot ahead she whistled to indicate her course. This time came the proper response, and a little later the motor boat shot past the towering sides of the river steamer. So near had a collision been that the girls could hear the complaining voice of the pilot of the large craft.
"What's the matter with you fellows?" the man cried, as he looked down on the girls. "Don't you know what you're doing?" Clearly he was angry.
"We got adrift, and the motor wouldn't start," cried Betty, in shrill tones.
"Pilot biscuit and puppy cakes!" cried the
