[I] _“Sea Warfare.” By Rudyard Kipling. (Macmillan.)_ No one knows how the title of “The Trade” came to be applied to the Submarine Service. Some say the cruisers invented it because they pretend that submarine officers look like unwashed chauffeurs. Others think it sprang forth by itself, which means that it was coined by the Lower Deck, where they always have the proper names for things. Whatever the truth, the Submarine Service is now “the Trade”; and if you ask them why, they will answer: “What else could you call it? The Trade’s ‘the trade,’ of course.” It is a close corporation; yet it recruits its men and officers from every class that uses the sea and engines, as well as from many classes that never expected to deal with either. It takes them; they disappear for a while and return changed to their very souls, for the Trade lives in a world without precedents, of which no generation has had any previous experience--a world still being made and enlarged daily. It creates and settles its own problems as it goes along, and if it cannot help itself no one else can. So the Trade lives in the dark and thinks out inconceivable and impossible things, which it afterwards puts into practice. _Four Nightmares._ Who, a few months ago, could have invented, or, having invented, would have dared to print such a nightmare as this: There was a boat in the North Sea who ran into a net and was caught by the nose. She rose, still entangled, meaning to cut the thing away on the surface. But a Zeppelin in waiting saw and bombed her, and she had to go down again at once, but not too wildly or she would get herself more wrapped up than ever. She went down, and by slow working and weaving and wriggling, guided only by guesses at the meaning of each scrape and grind of the net on her blind forehead, at last she drew clear. Then she sat on the bottom and thought. The question was whether she should go back at once and warn her confederates against the trap, or wait till the destroyers, which she knew the Zeppelin would have signalled for, should come out to finish her still entangled, as they would suppose, in the net. It was a simple calculation of comparative speeds and positions, and when it was worked out she decided to try for the double event. Within a few minutes of the time she had allowed for them, she heard the twitter of four destroyers’ screws quartering above her; rose; got her shot in; saw one destroyer crumple; hung round till another took the wreck in tow; said good-bye to the spare brace (she was at the end of her supplies), and reached the rendezvous in time to turn her friends.