"We're about ready now," he said. "You might bring that torpedo from the rack."
He indicated a cage-like basket, in which he had placed the metal globe after taking it from the closet.
"The torpedo?" said Tom, looking about him.
Not unnaturally the boy was looking for one of the cylindrical, cigar-shaped implements of war, which he had always associated with the word "torpedo."
Mr. Ironsides smiled slightly.
"I mean that metal globe," he said.
"What! Is that a torpedo?" demanded Tom incredulously.
"Yes, and one twenty times more powerful than the Whitehead type in use in our navy to-day."
"But it looks more like a bomb than a torpedo. Where is its driving machinery? How does it go through the water?"
"You'll see all that in a minute. For many reasons, the ordinary type of torpedo is not much used for submarine work. So I had to go to work and think out a torpedo of novel design as well as a boat. That globe is the result. Thank you," as Tom handed it to him, using every precaution against dropping it, as you may be sure.