"What's wrong, Ned?" cried Tom excitedly.
"I don't know! The propellers have stopped! We were running as an aeroplane you know. Now we're going down!"
"Bless my suspenders!" shouted Mr. Damon. "If we land in the midst of that conglomeration of ice it will be the end of us."
"But we're not going to land there!" cried Tom.
"How are you going to stop it?" demanded Mr. Nestor.
"By the gas machine!" answered Tom. "That will stop us from falling. Start it up, Ned!"
"That's right! I always forget about that! I'll have it going in a second!"
"Less than a second," called Tom, as he saw how near to the mighty, rushing avalanche they were coming.
Ned worked rapidly, and in a very short time the downward course of the airship was checked. It floated easily above the rushing flood of ice and earth, and Tom, seeing that his craft, and those on it, were safe, hurried back to his camera. Meanwhile the machine had automatically been taking pictures, but now with the young inventor to manage it, better results would be obtained.
Tom aimed it here and there, at the most spectacular parts of the avalanche. The others gathered around him, after Ned had made an inspection, and found that a broken electrical wire had caused the propellers to stop. This was soon repaired and then, as they were hanging in the air like a balloon, Tom took picture after picture of the wonderful sight below them. Forest after forest was demolished.