eyes on the page. A limited amount of smoking was permitted, but the air was sometimes so vitiated that only the most vigorous and incessant puffing could keep a cigarette alight. One of the most annoying things about the submarine existence is the fact that the air condenses on the sides as the coldness increases, so that practically everything becomes wet; as the sailor lies in his bunk this moisture is precipitated upon him like raindrops. This combination of discomforts usually produced, after spending a few hours under the surface, that mental state commonly known as "dopey." The usual duration of a "cruise" was eight days, and by the end of that time many of the crew were nearly "all in," and some of them entirely so. But the physical sufferings were the least discomfiting. Any moment the boat was likely to hit one of the mines the Germans were always planting. A danger which was particularly vexatious was that a British or an American submarine was just about as likely to be attacked by Allied surface craft as the Germans themselves. At the beginning, recognition signals were arranged by which it was expected that an Allied under-water craft, coming to the surface, could make its identity known to a friendly warship; sometimes these signals succeeded, but more frequently they failed, and the attacks which British and American destroyers made upon their own submarines demonstrated that there was no certainty that such signals would offer any protection. A rather grim order directed all destroyers and other patrol craft to sink any submarine on sight, unless there was positive information that a friendly submarine was operating in the neighbourhood. To a large extent, therefore, the life of our submarine sailors was the same as that of the Germans. Our men know how it feels to have a dozen depth charges explode around them, for not infrequently they have had to endure this sort of thing from their own comrades. Mistakes of this sort, even though not very numerous, were so likely to happen at any time that whenever an Allied submarine saw an Allied destroyer at a distance, it usually behaved just as a German would have behaved under the same conditions: it dived precipitately to the safety of deep water. Our men, that is, did not care to take the risk of a discussion with the surface craft; it was more prudent to play the part of an enemy. One day one of the American submarines, lying on the surface, saw an American destroyer, and, cheered in their loneliness by the sight of such a friendly vessel, waited for it to approach, making all the identification signals carefully set down in the books. Instead of a cordial greeting, however, about twenty rounds of projectiles began falling about the L-boat, which as hastily as possible dropped to sixty feet under the surface. In a few minutes depth charges began exploding around him in profusion, the plates of the vessel shook violently, the lights went out, and the end seemed near.