to fire the torpedo, since it is already in the tube?"

"Certainly, sir," nodded Jack. And then he continued as if reciting a
lesson: "Just give that firing lever at the back of the after port a
quick shove to the right and downward. That releases the charge of
compressed air and forces the torpedo out. At the same instant the
forward port opens, so that the torpedo can be shot out into the water.
The compressed air also serves to keep the sea water from rushing in
through the torpedo tube. When the lever is swung up and back again
that closes the forward port, and it is then safe to open this after
port."

"You've committed that to memory," laughed the naval lieutenant.

"Oh, we've often talked this over, all three of us," smiled Jack.

"Then, since you understand this part so well, Benson," proposed Mr.
Danvers, "perhaps you'd like to go forward, on deck, and see when this
dummy torpedo is fired?"

"I surely would," agreed the submarine boy "And Eph can just as well
come with me."

The two submarine boys, therefore, hastened above, out on the platform
deck, and then further forward on the upper hull, until they lay out
along the nose of the "Hastings."

Danvers reached Ewald's side in the tower, while Biffens waited below,
at the lever, for the firing signal.