Before the advent of the aeroplane and airship the gyroscope derived its practical importance from its applications to the torpedo and the gyroscopic compass, and neither of these applications originated in this country. With the introduction of aircraft the applications of the gyroscope become very numerous and of great importance. Navigation of such craft must be made precise by the provision of gyroscopic sextants; photography from aeroplanes, to be accurate, must be carried out by means of special cameras stabilised so that the photographs are true vertical productions; war aeroplanes must be steered and controlled in accordance with accurate dynamical principles, and in this respect the claims of the gyroscope cannot be ignored; bombing from aeroplanes must be rendered accurate by designing the bombsight as part of an accurate stabiliser; battleships must be provided with anti-aircraft devices controlled by stabilisers, and the guns on such ships must be controlled both with respect to the vertical and the horizontal, and in azimuth, by means of instruments of the greatest precision.