The latter crept away, plainly in great trouble of spirit.  Ikey asked his chum: 

“Did you hear it again?”

“Ye-es,” admitted Frenchy.  “It does sound queer.  What do you suppose it can be?”

“Don’t know.  Let’s tell Whistler,” said Ikey, who had a deal of confidence in Morgan.

“That’s all right.  But don’t tell him anything about our being in that room before.  Remember, Ikey, we don’t know a livin’ thing about that first periscope the lookouts spied.”

“Sure I won’t tell,” agreed the other.  “It wasn’t such a good joke after all, was it, Frenchy?”

And Frenchy agreed with a solemn nod of his head.

CHAPTER XVI

AN ACCIDENT

The Kennebunk shook throughout her structure at that moment and Ikey darted for the between-decks ladder.

“Another submarine!” he shouted.  “Oi, oi!”

“Hold on!” drawled Frenchy.  “Nothing like it.  There goes another.  They are at practice.  The target’s in range.”

The four Seacove boys had seen something of gun practice on the destroyer Colodia; but the secondary batteries of the smaller vessel made no such racket as did the big guns of the Kennebunk.

The discharge of a turret gun aboard the superdreadnaught was an important matter, and a costly one as well.  The gun crews practiced all the movements save the actual discharge of the guns every day.  To burn up several hundred pounds of powder and fire away the expensive projectiles in rehearsal was a serious matter.

The gun crew that had made a clean hit on the submarine with its first shell, had already shown what value practice shooting was.  The high standard of the gunnery in our Navy pays for all it costs.

These gunners had practiced at the schools and on other vessels before being assigned to the superdreadnaught.  No matter how much good powder and shot had already been flung away in training that particular crew of Turret Number Two, the sinking of the German submarine had paid for it all.

Whistler and Torry did not, of course, actually fire the gun.  The gun captain did that.  But the exact team work of the crew had much to do with the score of the gun in target practice; and the two friends did their work commendably.

There was a sharp lookout kept during target practice for other submarines.  The disappearance of the first periscope which had been hailed from the masthead was the cause of much discussion.  It was generally believed that this first submarine had wisely made off when its sister ship was so promptly sunk by the battleship.

Frenchy and Ikey almost burst from their desire to tell what they knew about the mystery.  But they did not dare.

It had been a lesson which the two mischief-loving boys would not easily forget.  While the whole ship’s company was watching the imitation periscope Frenchy and Ikey had slipped overboard through the ash-chute, the real submarine might have torpedoed the Kennebunk.