was, however, the natural outcome of a close study of German naval methods. The man who first had the idea well understood the peculiar mentality of the U-boat commanders. The Germans had a fairly easy time in the early days of submarine warfare on merchant shipping. They sank as many ships as possible with gunfire and bombs. The prevailing method then was to break surface, and begin shelling the defenceless enemy. In case the merchant ship was faster than the submarine she would take to her heels; if, as was usually the case, she was slower, the passengers and crews lowered the boats and left the vessel to her fate. In such instances the procedure of the submarine was invariably the same. It ceased shelling, approached the lifeboats filled with survivors, and ordered them to take a party of Germans to the ship. This party then searched the vessel for all kinds of valuables, and, after depositing time bombs in the hold, rowed back to the submarine. This procedure was popular with the Germans, because it was the least expensive form of destroying merchant ships. It was not necessary to use torpedoes or even a large number of shells ; an inexpensive bomb, properly placed, did the whole job. Even when the arming of merchant ships interfered with this simple programme, and compelled the Germans to use long-range gunfire or torpedoes, the submarine commanders still persisted in rising to the surface near the sinking ship. Torpedoes were so expensive that the German Admiralty insisted on having every one accounted for. The word of the commander that he had destroyed a merchant ship was not accepted at its face value; in order to have the exploit officially placed to his credit, and so qualify the commander and crew for the rewards that came to the successful, it was necessary to prove that the ship had actually gone to the bottom. A prisoner or two furnished unimpeachable evidence, and, in default of such trophies, the ship's papers would be accepted. In order to obtain such proofs of success the submarine had to rise to the surface and approach its victim. The search for food, especially for alcoholic liquor, was another motive that led to such a manoeuvre ; and sometimes mere curiosity, the desire to come to close quarters and inspect the consequences of his handiwork, also impelled the Hun commander to take what was, as events soon demonstrated, a particularly hazardous risk.
