then the balloon took shape and form. The bag was of the usual cigar shape, divided into many compartments so that the puncture of one would not empty out all the vapor.
Below the bag was a car or cabin made of light wood. It was all enclosed and contained besides the motor, storage tanks for gasolene, oil and other things, sleeping berths, a tiny kitchen, a pilot house, and a room to be used for a living apartment. Everything was very compact, and there was not half the room there was in some of Tom Swift's other airships. But then the party did not expect to make long voyages. They could take along a good supply of canned and also compressed food, much of which was in tablet or capsule form, and of course they would take their weapons, and ammunition.
"And I hope you'll leave room for plenty of gold," said Ned in a whisper to Tom, as they completed arrangements for the gas test.
"I guess we can manage to store all that we can get out of the underground city," replied his chum. "I'm going to find a place for the big gold statue if we can manage to lift it."
"Say, we'll be millionaires all right!" exulted Ned.
Though much still remained to be done on the balloon, it was soon in shape for an efficient test,
