igns of weakness
when it became subjected to a pressure of thirty-eight tons, and burst
at a joint when under a pressure of forty-three tons per square inch.
You may therefore feel quite satisfied that the generator is fully equal
to a continuous pressure of at least fifteen tons, instead of the trifle
over two which it will have to sustain."

The remainder of the machinery possessing no very startling or novel
features, it was passed by with merely an admiring glance at its
exquisite finish; and the quartette, leaving the engine-room, passed
round on the other side of the spiral staircase to a room marked "Diving
Room."

Entering this they found themselves in an apartment about twenty feet
square, one side of which was wholly occupied by four cupboards labelled
respectively "Sir Reginald Elphinstone," "Colonel Lethbridge,"
"Lieutenant Mildmay," and "Von Schalckenberg."

"This," explained the professor, "is the room wherein we shall equip
ourselves for our submarine rambles; and here," opening one of the
cupboards, "are the costumes which we shall wear upon such occasions."

The opened cupboard contained an ordinary indiarubber diving-dress, a
sort of double knapsack, a number of heterogeneous articles, and,
lastly, a suit of armour.

"Why, professor, what, in the name of all that is comical, is the
meaning of this? Are we to walk forth among the fishes equipped like
the knights of old?" asked the baronet, pointing to the armour.

"I will explain," said the professor. "In an ordinary diving-dress a
man can only descend to a depth of something like fifteen fathoms.
Instances have certainly occurred where this depth has been exceeded, a
Liverpool diver named Hooper having descended as far as thirty-four
fathoms, if my information is correct; but this was quite an exceptional
circumstance; and, as I have said, fifteen fathoms may be taken as the
average depth at which a man can move about and work in comfort. The
reason for this limit is that beyond it the pressure of the water on the
exposed hands is so great as to drive the blood to the head and bring on
a fainting fit, if nothing worse; besides which, the volume of air
inside the dress necessary to counteract the outside pressure of the
water would be so great as to speedily result in suffocation. Now, if
our explorations were limited to a depth of fifteen fathoms only they
would hardly be worth the undertaking; so I have devised these suits of
armour, in whi