Krupp battery telescope
The 75mm quick-firing mountain guns M. 194 were equipped with a Krupp battery telescope composed by the prismatic telescope, the aiming circle (cercle de pointage) and the tripod.
The prismatic telescope magnifies 8 times. Its ocular has vertical and horizontal divisions, each of which corresponds to 5 millièmes. The connection of the aiming circle with the tripod takes place by means of the base, into which the tail of the aiming circle is inserted. On the tail is threaded a copper ring, in which passes a micrometric screw, which allows the telescope to be adjusted with great precision.
The base consisted of a hollow cylinder with a stem. The cylinder is split at one end and has two lugs through which the screw passes to tighten it. On its side, the cylinder has two levels located at right angles. These levels serve to give the tube a horizontal position. At its lower end, the stem of the cylinder ends with a sphere, which serves as the axis of rotation of the entire device.
The aiming circle of the telescope has the same device as the gun aiming circle. On the right side of the movable ring is a tide with an arc-shaped cover inside which a cursor is nested. The left side of the cursor forms a socket for the telescope, and its right arc-shaped side is serrated below. By means of a lead screw which passes in front of the tide of the ring and engages the toothed part of the cursor which can be moved (tilted) forwards and backwards, enabling the angles of sight to be measured quickly and easily. Readings are taking at the divisions marked on the right side of the tide and the cursor. These divisions correspond exactly to the divisions of the level and vernier found on the bar sight.
The tripod consists of two parts : the head and the legs. The head has a spherical socket for the sphere of the base, and four screws for bringing the levels horizontally and for tightening the sphere. The legs are composed of two brass tubes that fit into each other. They can be placed at any height by pulling out tubes and extending their propellers. The aiming circle and the tripod are carried in leather bags.
Use of the battery telescope
To place the battery telescope, take the tripod out of its bag and place it at the required height. Loosen the tightening screw. Take the aiming circle out of its bag and, after placing the telescope on it, put it on the base. Finally tighten the screw to fix the base. After each use, the telescope should be cleaned well, and then its clean parts should be lightly oiled and placed in their bag.
To measure the angle of sight, set the aiming circle and the drum at zero. Rotate the telescope to approximate the direction in which to measure the angle. Tighten the screw on the base. Bring the levels horizontally one by one, acting with their screws, which lie in the direction of the level. Tighten the screws to prevent the sphere from wobbling. By means of the micrometric screw, bring the line of sight exactly in the plane of the object whose angle of sight you want to measure. At the same time, by acting on the cursor screw, bring the centre of the intersection to coincide with the object. Read the required angle by the divisions for the angle of sight.
To measure the auxiliary angle, set the aiming circle and the drum at zero. Lay the telescope at the target (10 m to the left of its right end). By acting on the drum, move the telescope in the direction of the auxiliary aiming point. The required angle is calculated on the aiming circle and the drum.
To measure the width of the target, you can proceed in the same way as for measuring the auxiliary angle. However, the same measurement can be made on the horizontal divisions in the field of the telescope, remembering that each of them is 5 millièmes.
To measure the height of burst of the shrapnel and the lateral deflection of falls, when the telescope is laid at the target so that its crosshair coincides with the base of the target, ½ division of the vertical divisions in its field will approximately determine the normal bursts (3/1000). Lateral falls are measured along the horizontal divisions in the field of view of the telescope.
SOURCE : Описание на 7.5 см. с.с. планиско оръдие обрасецъ 1904 г. Sofia : Печатница “Балканъ” 1907, pp. 37-39.