ter
scored nine hits, but was at last driven off by the appearance of
a destroyer. To cite another typical engagement, the _Navajo_, in
the English Channel, July 4, 1917, was attacked first by torpedo
and then by gunfire. The 27th shot from the ship hit the enemy's
conning tower and caused two explosions. "Men who were on deck
at the guns and had not jumped overboard ran aft. The submarine
canted forward at an angle of almost 40 degrees, and the propeller
could be plainly seen lashing the air."[1]

[Footnote 1: For more detailed narratives of this and other episodes
of the submarine campaign, see Ralph D. Payne, THE FIGHTING FLEETS,
1918.]

In coastal waters where traffic converged, large forces of destroyers
and other craft were employed for purposes of escort, mine sweeping,
and patrol. Yet, save as a means of keeping the enemy under water
and guarding merchant ships, these units had only a limited value
owing to the difficulty of making contact with the enemy. During
the later stages of the war destroyers depended chiefly upon the
depth bomb, an invention of the British navy, which by means of
the so-called "Y guns" could be dropped in large numbers around
the supposed location of the enemy. It was in this way that the
United States Destroyers _Fanning_ and _Nicholson_, while engaged
as convoy escorts, sank the _U-58_ and captured its crew.

The "mystery" or "Q" ships (well-armed vessels disguised as harmless
merchantmen) were of slight efficacy after submarines gave up surface
attack. In fact, it was the submarine itself which, contrary to all
pre-war theories, proved the most effective type of naval craft against
its own kind. Whereas fuel economy compelled German submarines to
spend as much time as possible on the surface, the Allied under-water
boats, operating near their bases, could cruise awash or submerged
and were thus able to creep up on the enemy and attack unawares.
According to Admiral Sims, Allied destroyers, about 500 in all, were
credited with the certain destruction of 34 enemy submarines; yachts,
patrol craft, etc., over 3000 altogether, sank 31; whereas about 100
Allied submarines sank probably 20.[1] Since 202 submarines were
destroyed, this may be an underestimate of the results accomplished
by each type, but it indicates relative efficiency. Submarines kept
the enemy beneath the surface, led him to stay farther away from
the coast, and also, owing to the disastrous consequences that might
e