The gyroscope has been utilized to give steadiness to vessels in rough seas, and Sperry has made considerable progress in this country in applying it to give stability to an aeroplane. One of the most successful of the recent applications of the gyroscope is in its connection with the marine compass. All battleships in the United States Navy are now fitted with the gyroscopic compass. As a gyro compass is independent of the magnetism of the earth and of the ship, and, when running properly, always points to the North Pole, its great convenience in vessels carrying heavy guns and armor, the attraction of which would materially interfere with the operation of the ordinary type of compass, is at once apparent. Another important use of the gyroscope is found in its relation to the vertical and horizontal steering gear of the naval torpedo, especially the Whitehead pattern. Its first application to this purpose was made by an officer in the Austrian navy in 1895, and this device, or an improved modification of it, such as the Angle Gyroscope, invented by Lieut. W. I. Chambers of the United States Navy, is in use on all torpedoes. Why are Finger-prints Used for Identification? The plan of identifying people by their finger-prints, although at first used only on criminals, is now put to many other uses. It was introduced originally in India, where it was of very great assistance to the British authorities in impressing the natives with the fact that at last no evasion of positive identification of culprits was possible. It was later taken up by the Scotland Yard authorities in England, and its use has since spread to practically every country in the civilized world. It has been proven, to the entire satisfaction of everyone who has ever made a careful study of the subject, that every human being has a marking on his or her fingers which is different from that of any other person on earth. Not only is it sure that no one else has a thumb or finger marked like yours, but it has also been established beyond dispute that every little detail will continue peculiar to your fingers as long as you have them. There are many ways in which this knowledge is used to advantage; two methods now employed are particularly valuable. It is seldom that an unpremeditated crime is committed without its author leaving finger-marks on some object which is unconsciously touched, such as silver plate, cash boxes or safes, glassware or windows, polished wood-work, etc., and very often the professional criminal also neglects to take precautions against leaving his signature behind him. It is then a simple matter for the police to collect such marks for comparison with the finger-prints of anyone to whom suspicion may be directed.