OBSERVING INSTRUMENTS.
B. C. Telescope, M. 1915.
The B. C. Telescope, M. 1915, is a binocular observing instrument of the scissors type. The two tubes of the telescope may be clamped either in a vertical or a horizontal position. In the former position the objectives are 12 inches above the eyes of the observer, and in the latter position they are 24 inches apart and at the same height as the eyes of the observer. In both cases they permit the observer to take advantage of some shield or other cover and still obtain a full view of the sector of observation. The tubes may be adjusted for the observer’s interpupillary distance in either the vertical or the horizontal position. The eyepieces may be adjusted to the eyes of the observer by screwing in or out.
BATTERY COMMANDER’S TELESCOPE MODEL OF 1915.
36-22-31
The principal parts of the telescope are:—Leveling mechanism, azimuth mechanism, elevating mechanism, angle of site mechanism, the telescopes and the tripod. A carrying case is provided separately for the instrument and for the tripod. In garrison a storage case is also provided.
The leveling mechanism consists of a ball and socket joint operated by the vertical spindle clamping screw.
The azimuth mechanism consists of the azimuth worm knob with its lever, operating the azimuth worm and worm wheel; the adjusting or slow motion knob and the azimuth clamp. The azimuth limb is divided into 64 parts, each division representing 100 mils. The azimuth micrometer is divided into 100 equal parts or mils, numbered every 10 mils. One complete revolution of the micrometer is equal to one division of the limb. The scales therefore correspond to those on the panoramic sight, 6400 mils to the circumference.
The leveling mechanism is operated by the small elevation worm knob.
The angle of site mechanism consists of the level, the angle of site scale and micrometer with its worm knob.
The telescopes consist of the eyepieces, telescopic tubes with their optical systems. In the right eyepiece is a graduated cross wire which can be rotated for either the horizontal or the vertical position.
The tripod is similar to the usual telescopic instrument tripod.
The optical characteristics of the instrument are as follows:—Power 10; field of view 75 mils; focal length of objectives 11½ inches; the field is flat, free from chromatic and spherical aberration, coma and distortion.