When this work had been completed, the two boys took the infernal-machine down to the frozen surface of the lake where there could be no danger from an explosion, and connected it with wires which they laid along the surface from the steep, snow-buried shore.

“Must be twenty feet of snow in there!” exclaimed Bruce, as for the third time he lost his footing and slid to the bottom of the slope.

Presently they were well behind the ridge in the forest, and out of range of any flying splinters of machine or ice.

“I feel as I used to when I was a schoolboy, and hid with the rest of the gang out in the woods and shot off charges of gunpowder in a gas-pipe bomb,” grinned Barney, as he screwed one wire to a post of a battery.

“Now we’ll—­” he exclaimed breathlessly.

His last word was lost in the roar of a tremendous explosion.  The shores of the bay took up the sound and sent it echoing and reechoing through the forest.  Fine bits of ice came rattling down through the trees, while a great cloud of smoke and mist floated lazily over their heads.

“Whew!  Some explosion!” murmured Barney.

Bruce was silent.  His face was white.

“What’s up?” asked Barney.

“Nothing.  I’m all right,” Bruce smiled grimly.  “I was only thinking what might have happened yesterday.”

“Forget it,” grumbled Barney.  “C’mon, let’s see the ruins.”

“Fish!” exclaimed Bruce, as they emerged from the forest.  And assuredly there were fish in abundance.  The thirty-foot wide pool, from which the ice had been blown, was white with them.  There were salmon, salmon-trout, white-fish, lake-trout, flounders, and others the boys did not know.  Hundreds and hundreds of them, stunned by the explosion, floated on the surface only waiting to be harvested.

“We’ll have to work carefully,” said Barney, starting forward.  “The ice is pretty well shattered.  A plunge in that water, and the temperature at thirty below, wouldn’t be pleasant, but I believe we can save every one of them.  Get a pole.”  He began cutting a large branch from a spruce tree.  Bruce followed his example.

“Now!” Barney exclaimed, preparing to slide down the bank.  But he paused in surprise.  The snow-bank, shattered by the blast, had gone tumbling down to the surface of the lake.  And what was that protruding above what remained of the snow?  It was dark and V-shaped, like the gable of a roof.

Barney was for investigating at once, but Bruce was more practical; the fish must be secured immediately.  This food might yet stand between them and starvation.

They were soon whipping the pool with their poles, and, as the fish came to the ice edge, they gathered them in.  Some were monsters, two or three feet in length.  It was, indeed, a great haul.  They piled them on the ice like cord-wood.  Already they were freezing; they would remain fresh for months.