“Not half as much as you have, Dad,” interrupted the lad, for Tom was a modest youth.

“You should see his sky racer,” went on the old inventor.

“Sky racer?  What’s that?” asked Mr. Durban.  “Is it another kind of gun or cannon?”

“It’s an aeroplane—­an airship,” explained Mr. Swift.

“An airship!” exclaimed the old elephant hunter.  “Say, you don’t mean that you make balloons, do you?”

“Well, they’re not exactly balloons,” replied Tom, as he briefly explained what an aeroplane was, for Mr. Durban, having been in the wilds of the jungle so much, had had very little chance to see the wonders and progress of civilization.

“They are better than balloons,” went on Tom, “for they can go where you want them to.”

“Say!  That’s the very thing!” cried the old hunter enthusiastically.  “If there’s one thing more than another that is needed in hunting in Africa it’s an airship.  The travel through the jungle is something fierce, and that, more than anything else, interferes with my work.  I can’t cover ground enough, and when I do get on the track of a herd of elephants, and they get away, it’s sometimes a week before I can catch up to them again.”

“For, in spite of their size, elephants can travel very fast, and once they get on the go, nothing can stop them.  An airship would be the very thing to hunt elephants with in Africa—­an airship and this electric rifle.  I wonder why you haven’t thought of going, Tom Swift.”

“I have thought of it,” answered the young inventor, “and that’s why I asked you in.  I want to talk about it.”

“Do you mean you want to go?” demanded the old man eagerly.

“I certainly do!”

“Then I’m your man!  Say, Tom Swift, I’d be proud to have you go to Africa with me.  I’d be proud to have you a member of my hunting party, and, though I don’t like to boast, still if you’ll ask any of the big-game people they’ll tell you that not every one can accompany Aleck Durban.”

Tom realized that he was speaking to an authority and a most desirable companion, should he go to Africa, and he was very glad of the chance that had made him acquainted with the veteran hunter.

“Will you go with me?” asked Mr. Durban.  “You and your electric gun and your airship?  Will you come to Africa to hunt elephants, and help me get the big tusks I’m after?”

“I will!” exclaimed Tom.

“Then we’ll start at once.  There’s no need of delaying here any longer.”

“Oh, but I haven’t an airship ready,” said the young inventor.  The face of the old hunter expressed his disappointment.

“Then we’ll have to give up the scheme,” he said ruefully.

“Not at all,” Tom told him.  “I have all the material on hand for building a new airship.  I have had it in mind for some time, and I have done some work on it.  I stopped it to perfect my electric rifle, but, now that is done, I’ll tackle the Black Hawk again, and rush that to completion."-