destroyed and
particularly the methods of destruction. But we know that a few have
met their fate from bolts dropped from the blue. In _The Outlook_
Lawrence La Tourette Driggs, himself a flying man of no contemptible
record, describes the method and result of such an attack. After
recounting the steps by which a brother airman attained a position
directly above a submerged submarine preparatory to dropping his
bomb, he says:

Down shot his plummet of steel and neatly parted the waters ahead
of the labouring submarine. But it did not explode. I could see a
whirling metal propeller on the torpedo revolve as it sank. It
must have missed the craft by twenty feet.

Suddenly a column of water higher than my position in the air
stood straight up over the sea, then slipped noiselessly back. By
all that is wonderful how did that happen?

As we covered the spot again and again in our circling machines,
we were joined by two more pilots, and finally by a fast clipper
steam yacht. The surface of the water was literally covered with
oil, breaking up the ripple of the waves, and smoothing a huge
area into gleaming bronze. Here and there floated a cork belt,
odd bunches of cotton waste, a strip of carpet, and a wooden
three-legged stool. These fragments alone remained to testify to
the _corpus delicti_.

"Philip," I said half an hour later, as the hot coffee was
thawing out our insides, "what kind of a civilized bomb do you
call that?"

"That bears the simple little title of trinitrotoluol; call it T.
N. T. for short," replied Sergeant Pieron.

"But what made it hang fire so long?" I demanded.

"It's made to work that way. When the bomb begins sinking the
little propeller is turned as it is pulled down through the
water. It continues turning until it screws to the end. There it
touches the fuse-pin and that sets off the high explosive--at any
depth you arrange it for."

I regarded him steadfastly. Then I remarked, "But it did not
touch the submarine. I saw it miss."

"Yes, you can miss it fifty yards and still crush the submarine."
He took up an empty egg shell. "The submarine is hollow like
this. She is held rigidly on all her sides by the water. Water is
non-compressible like steel. Now when the T. N. T. explodes, even
some distance away, the violent expendi