Position Finder

An instrument for determining the position of objects which are to be fired at from forts. It is designed for use from forts situated on the water. Fiske's position finder may be thus generally described. On a chart the channel is divided into squares, and the position finder determines the square in which a ve el lies. For each square the direction and elevation of the guns is calculated beforehand. The enemy can therefore be continuously located and fired at, although from smoke or other cause the object may be quite invisible to the gunner. It comprises two telescopes situated at distant extremities of as long a base line as is obtainable. These telescopes are kept directed upon the object by two observers simultaneously. The observers are in constant telephonic communication. As each telescope moves, it carries a contact over an arc of conducting material. Below each telescope is an arm also moving over an arc of conducting material. These arcs enter into a Wheat stone bridge and are so connected that when the arm and the distant telescope are at the same angle or parallel a balance is obtained. Thus each observer has the power of establishing a balance. A chart is provided for each of them, and over it the arm connected with the distant telescope and an arm or indicator attached to the telescope at that station move so that as long as both telescopes point at the object and each observer maintains the electric balance, the intersection of the arms shows the position on the chart. The Position Finder is a simplification and amplification of the Range Finder, q. v. In practice the observers may be placed far from the forts, and may telephone their observations thereto. It has been found accurate within one-third of one per cent. 428   STANDARD ELECTRICAL DICTIONARY.