that she was in perfect control as an aeroplane, he started the gas
machine, filled the big black bag overhead, and, when it was
sufficiently buoyant, he shut off the motor, and the Black Hawk
floated along like a balloon.

"That's what we'll do if our power happens to give out when we get
over an African jungle, with a whole lot of wild elephants down
below, and a forest full of the red pygmies waiting for us,"
explained Tom to Mr. Durban.

"And I guess you'll need to do it, too," answered the hunter. "I
don't know which I fear worse, the bad elephants wild with rage, as
they get some times, or the little red men who are as strong as
gorillas, and as savage as wolves. It would be all up with us if we
got into their hands. But I think this airship will be just what we
need in Africa. I'd have been able to get out of many a tight place
if I had had one on my last trip."

While the Black Hawk hung thus, up the air, not moving, save as the
wind blew her, Tom with his father and Mr. Jackson made an
inspection of the machinery to find out whether it had been strained
any. They found that it had worked perfectly, and soon the craft was
in motion again, her nose this time being pointed toward the earth.
Tom let out some of the gas, and soon the airship was on the ground
in front of the shed she had so recently left.

"She's all right," decided the young inventor after a careful
inspection. "I'll give her a couple more trials, put on the
finishing touches and then we'll be ready for our trip to Africa.
Have you got everything arranged to go, Ned?"