been on so many trips with me?"

"No, it isn't exactly that, Tom. I'd go in a minute if you didn't have
this new fangled thing on your airship. But how do you know how it's
going to work--or whether it will work at all? We may come a cropper."

"Bless my insurance policy!" exclaimed a man who was standing near the
two lads who were conversing. "You'd better keep near the ground, Tom."

"Oh, that's all right, Mr. Damon," answered Tom Swift. "There isn't any
more danger than there ever was, but I guess Ned is nervous since our
trip to the underground city of gold."

"I am not!" indignantly exclaimed the other lad, with a look at the
young inventor. "But you know yourself, Tom, that putting this new
propeller on your airship, changing the wing tips, and re-gearing the
motor has made an altogether different sort of a craft of it. You,
yourself, said it wasn't as reliable as before, even though it does go
faster."

"Now look here, Ned!" burst out Tom. "That was last week that I said it
wasn't reliable. It is now, for I've tried it out several times, and
yet, when I ask you to take a trip with me, to act as ballast--"

"Is that all you want me for, Tom, to act as ballast? Then you'd better
take a bag of sand--or Mr. Damon here!"

"Me? I guess not! Bless my diamond ring! My wife hasn't forgiven me for
going off on that last trip with you, Tom, and I'm not going to take any
more right away. But I don't blame Ned--"