craft, and had done such good service that he thought, in building a
successor, that he could do no better than to follow the design of
the skyship which had been destroyed in the ice caves. But, on
talking with the old elephant hunter, and learning something of the
peculiarities of the African jungle the young inventor decided on
certain changes.

In general the Black Hawk would be on the lines of the Red Cloud but
it would be smaller and lighter and would also be capable of swifter
motion.

"You want it so that it will rise and descend quickly and at sharp
angles," said Mr. Durban.

"Why," inquired Tom.

"Because in Africa, at least in the part where we will go, there are
wide patches of jungle and forest, with here and there big open
places. If you are skimming along close to the ground, in an open
place, in pursuit of a herd of elephants and they should suddenly
plunge into the forest, you would want to be able to rise above the
trees quickly."

"That's so," admitted Tom. "Then I'll have to use a smaller gas bag
than we had on the other ship, for the air resistance to that big
one made us go slowly at times."

"Will it be as safe with a small bag?" Mr. Damon wanted to know.

"Yes, for I will use a more powerful gas, so that we will be more