there, Captain Dresser!" said, laughingly, a young
naval officer standing near, who kindly took all further trouble off the
Captain's hands in the way of answering Bob's questions and showing him
round the ship, the machinery of which especially charmed him, being so
much more imposing and complicated than that of the poor _Bembridge
Belle_, which had interested him only yesterday, so to speak, though now
washed to pieces by the relentless sea!

The movements of the eccentric aroused Bob's chief wonder, the two
piston-rods connected with it and guiding the motion appearing in their
working like the crooked limbs of a bandy-legged giant "jumping up and
down," as he expressed it, "in a hoppety-kickety dance."

Bob was called up from the engine-room by an extraordinary sound that
proceeded apparently from the deck above.

This, as he ascended, grew louder and louder; until it became to him
really awesome.

"What is that?" he asked the young lieutenant, who had accompanied him
below and now followed him up, keeping close to his side. "Has anything
happened, sir?"

"No, nothing's happened," replied the young officer, who was a bit of a
wag. "That is our steam siren."

"What is that, sir?" said Bob again--"I don't understand you."

"It's the siren," explained the other, "a thing like the steam-whistle,
for signalling to passing ships."

"It makes an awful row," cried Bob. "Don't you think so, sir?"

"It does," said the lieutenant laughing. "A great row!"

"Why do they call it a siren, though?" inquired the insatiable Bob.
"The `sirens' I've read of in my lessons at school used to be mermaids
that sang so sweetly and made such beautiful music, as they played on
their harps or lyres, that they lured poor mariners to destruction!"

"But doesn't our siren make beautiful music?" asked the lieutenant in a
joking way. "It is loud, it is true; but don't you think it sweet?"

"No," answered Bob, most emphatically. "It isn't! It is more like a
thousand wild bulls all with the toothache and roaring with pain!"

"That's not a bad description," said the other, laughing heartily again.
"Hullo, though, they are going to fire now! Don't you see they've just
run up a red flag on that spar we have forward as an apology for a
mast?"

"I see," replied Bob, concentrating his attention on the preparations
being made around for testing the machine-guns and larger weapons with
which the vessel was armed, long cylindrical sho