evidently moved the time of arrival up to noon. The destroyers, slowing down so that they would not arrive ahead of time, started for the designated spot. Sometimes thick weather made it impossible to fix the position by astronomical observations, and the convoy might not be at its appointed rendezvous. For this reason the destroyers now deployed on a north and south line about twenty miles long for several hours. Somewhat before the appointed time one of the destroyers sighted a faint cloud of smoke on the western horizon, and soon afterward thirty-two merchantmen, sailing in columns of fours, began to assume a definite outline. At a signal from this destroyer the other destroyers of the escort came in at full speed and ranged themselves on either side of the convoy--a manoeuvre that always excited the admiration of the merchant skippers. This mighty collection of vessels, occupying about ten or twelve square miles on the ocean, skilfully maintaining its formation, was really a beautiful and inspiring sight. When the destroyers had gained their designated positions on either side, the splendid cavalcade sailed boldly into the area which formed the favourite hunting grounds for the submarine. As soon as this danger zone was reached the whole aggregation, destroyers and merchant ships, began to zigzag. The commodore on the flagship hoisted the signal, "Zigzag A," and instantaneously the whole thirty-two ships began to turn twenty-five degrees to starboard. The great ships, usually so cumbersome, made this simultaneous turn with all the deftness, and even with all the grace of a school of fish into which one has suddenly cast a stone. All the way across the Atlantic they had been practising such an evolution; most of them had already sailed through the danger zone more than once, so that the manoeuvre was by this time an old story. For ten or fifteen minutes they proceeded along this course, when immediately, like one vessel, the convoy turned twenty degrees to port, and started in a new direction. And so on for hours, now a few minutes to the right, now a few minutes to the left, and now again straight ahead, while all the time the destroyers were cutting through the water, every eye of the skilled lookouts in each crew fixed upon the surface for the first glimpse of a periscope. This zigzagging was carried out according to comprehensive plans which enabled the convoy to zigzag for hours at a time without signals, the courses and the time on each course being designated in the particular plan ordered, all ships' clocks being set exactly alike by time signal. Probably I have made it clear why these zigzagging evolutions constituted such a protective measure. All the time the convoy was sailing in the danger zone it was assumed that a submarine was present, looking for a chance to torpedo. Even though the officers might know that there was no submarine within three hundred miles, this was never taken for granted;