"II. The gyroscopic force is greater, other things being equal, as the velocity of motion of the axis is greater, as the velocity of rotation of the wheel is greater, as the mass of the wheel is greater and as this mass is more dis tantly situated as regards the centre of the wheel.* Practical application of the gyroscope dates back to 1744 when it was used to provide an artificial horizon for mariners at sea. Aside from its use as a fixed reference plane in clinometers and recorders, the gyroscope has been utilized in two contrary directions : (1) To produce motion in a suspended body at rest; and (2) to control the motion or the direction of motion of moving bodies. In the former field the most notable results have been in rolling a ship which is aground on a bar, so as to loosen it and permit its easier release; and its adaptation to ice-breaking vessels so as to cause them to roll, thus adding enormously to their effectiveness. In the latter field the gyroscope was applied first to controlling the tendency of torpedoes to wander, and to hold it constant to the direction in which it was aimed. The next application, and one of the most importance, was the development of the gyrocompass, an instrument far more reliable and accurate than the old magnetic compass with all its errors and deviations, and with the further advantage that it gives true north bearing, and not that of the wandering mag netic pole. This instrument is now used in
many of the naval vessels throughout the world. The next application was to prevent the rolling of ships, thus increasing the comfort of those ckn board, and, in the case of naval vessels, providing a level gun platform, which is of the greatest advantage in securing a larger number of hits. As all rolling of ships is the result of successive wave increments, the gyro scopic stabilizers need only be large enough tp counteract each of these increments as it arrives, and even for large ships the stabilizing gyroscope weighs only about I per cent of tile displacement. This mechanism has been suc cessfully applied to various type and sizes of vessels from 100 to 10,000 tons. The aeroplane stabilizer is another adaptation of the greatest importance, hardly yet emerged from the experimental stage, but already recognized as of great potentiality. The gyro-cars and gyro-automobiles have not achieved commer cial importance, their advantages being more than counterbalanced by operative difficulties.
dEROPLANES ; GYROCOMPASS; Mowokam, SYSTEMS; STEA MSHIPS; TORPEDO) . Consult Chatley, H., 'Practical Gyrostatic Balancing' (London 1912) • Cordeiro, F. J. B., The Gyro scope' (New York 1913) ; Crabtree, H., ning Tops and Gyroscopic Motion' (London 1914) ; Johnson, V. E., The Gyroscope: An Experimental Study' (London 1911) ; Worth ington, A. M., of Rotation' (Lon don 1899).