"Of course. The harder it blows the better the glider works. In fact I can't make much speed in a hundred-mile wind for with us all on board the craft will be heavy, and you must remember that I depend on the wind alone to give me motion."
"What do you think causes the wind to blow so peculiarly here Tom?" went on Ned.
"Oh, it must be caused by high mountain ranges on either side, or the effects of heat and cold, the air being evaporated over a certain area because of great heat, say a volcano, or something like that; though I don't know that they have volcanoes here. That creates a vacuum, and other air rushes in to fill the vacant space. That's all wind is, anyhow, air rushing in to fill a vacuum, or low pressure zone, for you remember that nature abhors a vacuum."
It took nearly a week to assemble the Vulture, as Tom had named his latest craft, from the fact that it could hover in the air motionless, like that great bird. At last it was completed and then, weights being taken aboard to steady it, all was ready for the test. Tom would have liked to have taken all his passengers in the glider, for it would work better then, but the three Russians were timid, though they promised to get aboard after the trial.
The test came off early one morning, Tom, Ned and Mr. Damon being the only ones aboard. Bags of sand represented the others. The glider was wheeled to the edge of the wind zone and they took their places in the car. It was hard work for the gale, that had never ceased blowing for an instant since they found its zone, was very strong. But the glider remained motionless in it, for the wing planes, the rudders, and equalizing weights had been adjusted to make the strain of the wind neutral.
"All ready?" asked Tom, when his chum and his friend were in the enclosed car of the glider.
"As ready as I ever shall be," answered Ned.
"Bless my suspenders! Let her go, Tom, and have it over with!" cried the odd man.
The young inventor pulled a lever, and almost instantly the glider darted forward. A moment later it soared aloft, and the three Russians cheered. But their voices were lost in the roar of the hurricane, as Tom sent his craft higher and higher.
It worked perfectly, and he could direct it almost anywhere. The wind acted as the motive power, the bending and warping wings, and the rudders and weights controlling its force.