But the most thrilling experiences of trench warfare are trench raids. These are not necessarily elaborate affairs. Some of them are quite informal. Their objects are twofold—the first, to keep the enemy guessing, the second, to obtain information. The second is the most important. It is vitally necessary to know just where every one of your enemy’s Divisions is located. The simplest method of finding out is to send over armed deputations in the dead of night, with instructions to bring back a few assorted Germans. These, when they arrive, are interrogated, and their equipment and shoulder-straps are examined, for clues as to their identity. In this way it is usually possible to discover what Divisions are in station opposite, and how much front each holds. If a Division is spread out widely, you may be tolerably sure that the enemy has no serious designs upon your sector of the line. But if Divisions are “distributed in depth”—that is, with narrow fronts and long tails—the wise commander begins to accumulate ammunition and draft reserves into his back areas. Before the great German drive in March, against the attenuated British line at St. Quentin, Sir Douglas Haig was made aware, by this and other means, of the cheering intelligence that he had opposite to a comparatively short sector of his front sixty-four German Divisions—or six more Divisions than there were British Divisions in the whole of France and Belgium! That was a case in which nothing could be done except put up the best defence possible with the troops available, for equally overwhelming odds were being massed against the rest of the British line. But in normal cases, to be forewarned is to be forearmed. Trench raids are intermittent affairs. Patrols, on the other hand, must be organized every night. These excursions are not necessarily belligerent. Their main object is to collect information, and to make sure that the enemy keeps to his own side of the street. If two patrols do meet, and feel constrained to “start something,” the one thing no one ever does is to pull a gun or throw a bomb. To do so would be to invite impartial participation in the game by the machine guns of both sides. It must be cold steel or nothing. As often as not, it is nothing. Two patrols may meet, and cut one another dead, like rival beauties on Fifth Avenue. One night Boone Cruttenden found himself detailed for patrol duty, with a sergeant and four men. The party were to scale the parapet, pass through a gap in the wire, and make a tour of a certain section of No Man’s Land. The whole operation, which was by this time a familiar one, was expected to occupy about an hour. Orders were given to the trench garrison that there must be no firing during this period.