For three days they sailed in and out over the great snow-covered peaks of the Alps. They did not go high up, for they wanted to be near earth when an avalanche would occur, so that near-view pictures could be secured. Occasionally they saw parties of mountain climbers ascending some celebrated peak, and for want of something better to photograph, Tom "snapped" the tourists.
"Well, I guess they're all out of avalanches this season," remarked Ned one afternoon, when they had circled back and forth over a mountain where, so it was said, the big snow slides were frequent.
"It does seem so," agreed Tom. "Still, we're in no hurry. It is easier to be up here, than it is walking around in a jungle, not knowing what minute a tiger may jump out at you."
"Bless my rubbers, yes!" agreed Mr. Damon.
The sky was covered with lowering clouds, and there were occasionally flurries of snow. Tom's airship was well above the snow line on the mountains. The young inventor and Ned sat in the pilot house, taking observations through a spyglass of the mountain chain below them.
Suddenly Ned, who had the glass focused on a mighty peak, cried out:
"There she is, Tom!"
"What?"
"The avalanche! The snow is beginning to slide down the mountain! Say, it's going to be a big one, too. Got your camera ready?"
"Sure! I've had it ready for the last three days. Put me over there, Ned. You look after the airship, and I'll take the pictures!"