Abstract: A compass, in particular one intended to be used for track finding on skis or in track finding races, which is affixed to the user's hand with a strap, and which compass is eminently convenient to use in said circumstances. The invention is particularly characterized in that the strap, one end of which has been affixed to the compass, passes slidably through an aperture in the base plate of the compass, forming an adjustable thumb loop, and that the part of the strap protruding from the aperture has a length enabling the strap to be wound around the wrist, and that the end portion of the strap can be secured in connection with compass or with the strap by buckle or equivalent so that the compass will be positioned upon the upper edge of the hand, adjacent to the thumb groin. The buckle or equivalent may be attached to the thumb loop.
Abstract: An apparatus is disclosed for determining a measured direction such as the direction of a ship or airplane relative to an external magnetic field such as the magnetic field of the earth. This apparatus comprises means for establishing a magnetic field rotating at constant angular velocity, located to influence the external magnetic field. The rotating magnetic field vector bears a known angular relationship as a function of time to the measured direction. A detector is located to be influenced by the rotating and external fields for detecting the occurrence of a predetermined angular relationship between the rotating and external magnetic field vectors.
Abstract: Spatially adaptable support means for orienting the compass card immersed in damping fluid within a spherical housing of a magnetic compass to a horizontal plane during installation in any given mounting surface, comprising a movable compass card support unit and means for adjustably selectively positioning the support unit relative to the mounting plane and the sphere thereby positioning the card in its horizontal plane.