Instrument determining geographical coordinates - has elements depicting space as well as earths sphere

摘要

a simple instrument for the determination of latitude and longitude of a point on the earth's surface, consists of a number of parts which can be moved relatively to each other, of which at least one represents space and at least one the geographical globe. The angles of elevation of various marked heavenly bodies and marked spots on the earth's surface and the corresponding geographical latitude can be read off. By providing a set of discs the effect of passage of time, and hence the longitude can be found. All that is required besides the apparatus itself is a vertical angle measuring apparatus, a radio receiver for the time transmitter or a chronometer. The apparatus itself consists in principle of space table (A), large circle flag (B) and time angle disc (C).