"Keep it up, Bob Somers!" shouted Tom Clifton, excitedly.
"Hi, hi!" cried Tim Sladder. "Go it, Billy—go it!"
Musgrove was going it. His short legs moved with wonderful rapidity. Leaning well forward, he kept up a steady rhythmic movement, occasionally spurting in a manner which showed that he had himself well under control.
Hackett, guarding his strength and wind, saw, first with astonishment, then dismay, that Billy Musgrove refused to be shaken off. He was, before very long, breathing hard; his eyes gleamed with determination; off in the distance he saw the end of the lake rounding in a semicircle—the goal.
The moment for the final spurt had arrived; he was ready to bend all his energies in a last desperate effort to draw away from the grinning face beside him, when a strange sound reached his ears.
It was a curious, crackling noise, which increased in intensity. Then a clear, sharp report like a pistol-shot suddenly reverberated across the lake. Instantly a dark line flashed over the surface of the ice directly in the path of the skaters.
As occasionally happens, the ice had been under a tension, which finally became so great as to cause it to crack, leaving a bare space perhaps five or six inches wide.
The unexpected incident caused the boys to check their momentum, but there was not sufficient time to stop, and Musgrove's skate, striking the edge of the crack, almost sent him headlong. It was only by a powerful effort that he managed to save himself.
Hackett and Somers, who had jumped the crack safely, turned their heads to see how Musgrove had fared—then, puffing and blowing, came to a stop.
"Fierce luck!" panted Musgrove. "Was just going to spurt, too. I had your measure, Tackett."