Another apparently trifling thing in the development of navigation is an electrical signalling device for indicating the exact angle the Captain wishes the helm set in making a turn. He presses a button, and the man at the wheel sets the rudder accordingly. A dial informs the Captain that the rudder is set as required. This is most important, because it tends to avoid collisions as the war-ships suddenly change their positions in column. We all remember how serious a collision, even going at slow speed, may be when we recall how three years ago the _Camperdown_ sunk the _Victoria_ of the English Mediterranean squadron on a peaceful day off the coast of Africa, in going through some simple evolutions, and when hundreds of brave sailors, including the Admiral of the fleet himself, were drowned, as the _Victoria_ went down before the small boats of the other vessels of the fleet could reach them. [Illustration: THE ADMIRAL WORKING SIGNALS AT NIGHT.] One of the great problems in naval tactics is to secure an effective method of signalling orders from ship to ship. In the night it is comparatively easy. A string of red and white alternating electric lights is strung from a yard downwards. An operator sits in front of a little box in which there are a lot of black keys on which are stamped a certain number of red and white dots. As he presses these keys, which are arranged in a circle and look like so many fancy dominoes, the red and white lights flash out in certain combinations. The operators see them, and signal back the same light. Each key pressed down means a certain letter, and it takes little time to send an order. In the daytime signals must be sent by flags, or by means of a contrivance with long arms such as we see on signal-towers on a railroad. As these arms are jerked into certain positions they tell a story of their own. During a battle by day or night all such systems are of little value because of the smoke. Whistles can be of little use, because the noise of battle would drown them. Electrical experts are trying to devise a system of telegraphing through the water, of course without the use of wires, but the outlook in that direction is not promising at present.