“I don’t know,” answered Tom. “We seem to be held fast.”
He further increased the speed of the propellers, and the gas machine was set to make vapor at its fullest capacity, and force it into the bag. Still the craft was held to the earth.
“Maybe the gas has no effect in this climate,” called Ned.
“It can’t be that,” replied Tom. “The gas will operate anywhere. It worked all right today.”
Suddenly she airship moved up a little way, and then seemed to be pulled down again, hitting the ground with a bump.
“Something is holding us!” cried Tom. “We’re anchored to earth! I must see what it is!” and, catching up his electric rifle, he dashed out of the cabin.
CHAPTER XII
AMONG THE NATIVES
For a moment after Tom’s departure the others stared blankly at one another. They could hear the throbbing and hum of the machinery, and feel the thrill of the anchored airship. But they could not understand what the trouble was.