Page:Popular Science Monthly Volume 88.djvu/705

 The Artifices of Modern Warfare

A submarine commander has but one means of judging the speed of the vessel to be attacked -by noting the size of the bow-wave thrown up by the intended victim. The correctness of the estimate means either a hit or a miss. The British have devised a clever method of confusing the German submarines. A huge bow-wave is painted on the sides of the ship, rendering it extremely difficult for the underwater craft to judge the speed accurately. In the insert is shown a heavy Austrian Skeda howitzer with hay to make it invisible to the Russian air-scouts