A portable hand-held compass for taking navigational bearings on distant objects during the day or at night. The compass has a hollow housing in which a compass card is mounted for rotation about a vertical axis, a viewing window in the housing through which compass readings are taken, and a sighting barrel incorporated in the housing for viewing a distant object along a horizontal viewing path. The compass also has a manually activated light emitting diode for illuminating a reticle, a semi-reflective mirror positioned across the sighting path for reflecting an image of the illuminated reticle to the eyepiece of the sighting barrel, means for automatically unclamping the compass card when the L.E.D. is activated, and means for automatically clamping the compass card when the L.E.D. is deactivated.
Disclosed is a structure of a telescope with compass which indicates the direction in which the telescope is pointed, at the periphery of the field of vision of the telescope. Referring to the compass used for the telescope: a magnet is provided in a compass direction indicating globe on whose outer circumference directions are indicated. This direction indicating globe is supported so as to float in a case containing a lubricating liquid such as oil, etc. This compass is attached to the body of the telescope (specifically, a pair of hand-held binoculars, etc.). Then, the compass direction indication of the direction indicating globe appears as an image at the same focal point as the focal point of the objective lens of the telescope. Referring to other forms of telescopes: the direction indication is especially applicable to a telescope attached to a stand. A gyrocompass fixed to the arms supporting the body tube is connected to a luminous diode or crystalline liquid indication means, etc. attached inside the body tube of the telescope by a conductor. The gyrocompass, because it is fixed to the arms, pivots with the body tube of the telescope. A signal of the gyrocompass which detects the direction in which the telescope is pointed, is indicated at the luminous diode indication means, etc. in the body tube through the conductor. Finally, this direction indication is perceived by the viewer through the ocular at the periphery of the field of vision of the telescope.