The recoil is constant, being 70 inches for all elevations. The recoil cylinder uses hydroline oil as the buffer medium. Throttling is obtained by three throttling bars running lengthwise of the cylinder which are of varying height to give a throttling effect with corresponding slots in the recoil piston. A counter-recoil buffer is fitted in the piston rod to take up the shock when the springs return the gun into battery. The trunnions on the cradle are mounted in bearings formed by a yoke which swivels in a pintle bearing provided at the front of the trail. _Traverse_ is obtained by means of a handwheel and screw mounted on the left side of the trail which swings the yoke in traverse carrying the gun with it. A traverse of 70 mils on each side of center is possible. _The piece is elevated_ by a double screw type of mechanism. The upper end is attached to the cradle and so raises and lowers it. The screw is operated thru gearing by two handwheels one on each side of the trail from 5° elevation dep. to 15° elevation. _The trail_ is of the solid type made up of flasks of channel section. It has housings for the axle and carries the pintle bearing in which the top carriage or yoke swings. A tool box is provided in the trail. A seat is provided on each side of the trail for the cannoneers. The lunette transom is fitted about 27 inches from the rear of the trail and carries a bearing that fits the limber pintle. A trail prop is provided for supporting the trail when limbering. The spade can be released and folded up on the trail when traveling. A traveling lock is provided on the trail for locking the gun when traveling. The piston rod and spring rods must be disconnected before the gun can be drawn back far enough to lock. _The wheels_ are 61 × 6 inch with rubber tires and band brakes. Some older vehicles have steel tires and are fitted with tire brakes. An armor plate _shield_ is fitted to the carriage for the protection of the personnel. _The instruments for sighting_ and laying the piece included a line sight, a rear sight, a front sight, a panoramic sight and a range quadrant. The line sight consists of a conical point as a front sight and a V notch as a rear sight. These are located on the Jacket of the gun, and are useful for giving a general direction to the gun. [Illustration: 4.7” Rifle] The sighting is similar to the 3”, 1902. The rear sight and front sight are used for direct aiming. The rear sight is a peep sight mounted on a range scale quadrant by a bracket on right side of the cradle. The front sight is a pair of cross wires mounted in a ring attached by a bracket on the cradle about 3 ft. ahead of the rear sight. The range scale quadrant has a socket in which the Standard U. S. Panoramic sight may be mounted. For indirect fire the gunner on the left of the carriage lays for direction only.