An Improved Instrument for Quickly Determining the True Bearing of Heavenly and Terrestrial Bodies, and Indicating Direction of March or Flight.

摘要

13,251. Tilney, W. A. Sept. 16. Stellar compasses; marching compasses.-An instrument ot the type comprising pointers, adjustable relatively to a bar or graduated arc or circle, and a magnetic compass, has two or more pointers pivoted about the same point. As shown, the base of a protractor a forms the bar, and the pointers e, f, g are pivoted at its centre beneath the compass h. The compass needle, pointers, and protractor are rendered self-luminous for night use. The protractor may have inwardly projecting tongues j and notches k, so that readings may be determined by touch, and clicking devices enabling the pointers to be set by sound may also be provided. The instrument may be used for indicating a direction of travel by night or day, the pointers f, g being set to the sun, stars, or landmarks, the bearings of which are known or are determined with the aid of the compass, and the pointer e being set to the desired direction. The instrument is reset at intervals to the changed bearings of the objects sighted. Specification 15,641/14 is referred to.