Again the "propeller" engaged the ice, and the _Spider_ forged ahead. Grace looked back, and saw where a big crack had appeared. It was constantly widening. Then came a thunderous report. The girls screamed, and Betty almost let go of the tiller. Then she grasped it more tightly, for she saw, with a shudder of fear, that black water was now all around them. "Stop! Stop!" cried Betty to Mollie. "Stop the boat! We're on a big cake of ice and we're floating away! Stop it!" In an instant Mollie had lifted the wheel, and in the next she had shut of the motor. The _Spider_ with the girl passengers was indeed marooned on an immense cake of ice, while all about were other cakes, grinding and smashing over one another. The river was breaking up fast. CHAPTER XX TO THE RESCUE "Oh--oh!" gasped Grace, when she saw the dark and seething water all around them. "Oh, we're--afloat!" "And it's a good thing, too!" exclaimed Betty quickly, as she squared the rudder-runner. "If we weren't afloat we'd be sinking, and I don't want to do that--it's too cold!" Thus spoke the practical Little Captain, for she realized that now was the time to gain control over the nerves of her chums. Once they became hysterical there would be no managing them. And, as she spoke she glanced sharply at Mollie, who had opened her mouth to say something, but had thought better of it. "But we're on a cake of--ice!" cried Amy. "And, as the old wolf said to Little Red Riding Hood, so much the better to keep afloat with, my dear!" went on Betty gaily, a condition which she was far from feeling. [Illustration: "WE ARE ON A CAKE OF ICE, AND WE ARE FLOATING AWAY!" _The Outdoor Girls in a Winter Camp._ _Page 160._] "Yes, it's a nice big cake, too!" declared Mollie, recognizing that Betty would need help--"backing-up"--in her efforts to calm the two more timid girls. "It's a lovely large cake," Mollie added. "The largest around of any. Just suppose we were on--that?" and she pointed to one about as large as a "five cent piece the ice man brings in on a hot day," to quote Betty's later characterization. "Oh, how can you make fun, when we may--when we may--may slip off any minute?" protested Grace, half tearfully. "Oh, why did we come out in this ice boat?" "Now look here!" and Betty spoke sharply. "Isn't it a good deal better to be jolly than glum? Of course it is. And we're in no immediate danger. As Mollie says, we may be thankful we are not on a small cake of ice. This will hold us nicely." "But we're floating down the stream," said Amy. "Of course we are," agreed Betty cheerfully. "A river never stands still, you know. We are floating down with the rest of the cakes. Pretty soon there will be an ice jam, and----" "Oh, don't say that!" begged Grace. "An ice jam! That's one of those terrible things where so many persons are killed."