=To measure the deflection and site of a target.=—Lay the zero on the aiming point as above. If the line of sight must be moved through a large angle, press down the azimuth worm lever as far as it will go and while holding it down move the azimuth mechanism until the line of sight is approximately directed upon the target; then release the worm lever and bring the cross wires accurately on the target by turning the azimuth worm knob (for deflection) and the elevation worm knob (for elevation). Center the site level. Read the deflection and site. For carrying the B. C. telescope assembled on the tripod, clamp tightly the vertical spindle clamping lever; close in and clamp the tubes of the telescope; slide up and clamp the lower tripod legs; then carry the telescope over the shoulder by grasping the tripod legs, tube bases of telescope resting on the shoulder. =To dismount the B. C. Telescope and to pack in carrying case.=—Screw in both eye pieces. Press on the locking plunger and lift the telescope vertically off the spindle. Unclamp the large friction clamp knob, bringing the tubes together and insert in the carrying case; close and lock the lid. In dismounting the tripod the leg separators of the upper sections should first be unclamped. After the lower legs have been assembled, they should be clamped. To set up the tripod the operation is reversed. Aiming Circle, M, 1916. =The Aiming Circle= is an angle measuring instrument only and consists of a telescope, leveling mechanism, angle of site device, elevating mechanism, azimuth circle and compass, mounted on a tripod. Its leveling, azimuth and angle of site mechanisms are similar to those in the B. C. Telescope, as is also the tripod. The elevating mechanism consists of elevating worm knob and gear connecting it with the telescope. The telescope has a universal focus, magnifying power of 4, and a field of 180 mils. The cross wires are illuminated by a window. The compass is secured by the needle release button. Care and Instructions. Glass compass cover should fit tightly. Compass needle when clamped should not rotate while instrument is revolved or tipped. When release button is pressed, compass must swing freely on pivot and again remain clamped when button is released. _Compass should be released only when aiming circle is set up and horizontal._ [Illustration: AIMING CIRCLE _36-22-30_ ] Bubble must remain approximately centered while instrument is turned 1600 mils. =To lay 0 on any point.=—Set both the azimuth index and the micrometer to read zero. Release the wing nut; turn the telescope toward the point and again tighten the wing nut. Bring the vertical wire accurately on the point by turning the adjusting worm wheel.