hey, with the drifters, form the main
strands of the finer meshes of our anti-U-boat net--would have been
wiped out many times over.

"At the instant the jar of the first explosion made itself felt, the
thought flashed through my mind that there actually was a U-boat lying
on the bottom, and that the explosive charge on the sweep had been
detonated against its hull. The 'bunched' explosions immediately
following also lent themselves to this theory, and it was not till the
distinct columns of blown water began rising in the air that I surmised
the real cause of them--mines, probably laid so close together that the
explosion of the first had set off the others. This fact we were shortly
able to establish beyond a doubt.

"What had happened, as nearly as we could reconstruct it, was this: The
U-boat had been a mine-layer, probably interrupted on its way to lay its
eggs off one of our main fleet bases. The chances are that it had been
sufficiently injured by my depth-charges to make it more of a risk than
its skipper cared to take to proceed farther from his base; quite
likely, indeed, he had to put back at once. Then the chance of preparing
a little surprise party for the ship responsible for his trouble must
have occurred to him, and the result was that a snug little nest of
mines was laid all the way around the marking buoy. Having more mines
than he needed to barrage the buoy, he had scuttled several of those
remaining after the first job was completed, and these had been the ones
set off by the explosive charge on the trawlers' sweep. The spreading of
wreckage as bait around the trap was probably an afterthought, for it
was so hurriedly done that it really defeated the end it was intended to
accomplish. I am inclined to think, in fact, that, if the mines had laid
round the buoy, with no spread of oil or wreckage left to decoy us into
them, they might have had a victim or two to their credit. They were
laid shallow enough to have bumped both sloops and destroyers, and the
exploding of a mine against the bows of one or the other of these may
well have been the first warning we had of Fritz's little joke. As it
was, that part of the show was so crudely done that it gave away that
something was wrong.

"Yes, I have always thought of that as 'Fritz's little joke,'" continued
the captain, bracing himself at a new angle to meet a rollicking
cork-screw action that was working into the ship's wallowings. "It was
just the sor