Penetration at all ranges has been increased with the new rifle (U.S.). At 200 to 300 yards protection is afforded by about 0.2 inch of steel plate and about 0.3 inch wrought iron; at same distances penetration in earth is 25 inches, in pine, 30 inches. GUN-PITS FOR FIELD-ARTILLERY. THE FRENCH GUN-PIT. =Description.=--The French gun-pit consists of an epaulement, whose general direction is perpendicular to the line of fire, with wings or returns at the sides, along which trenches are dug on the inside for the protection of the cannoneers. The earth for the epaulement is taken from a rectangular pit one and a half feet deep, and from the ramps and trenches leading to it. If there is not sufficient earth, more is obtained by digging a ditch in front. The lateral trenches may be prolonged and deepened to any extent. [Illustration: FIG. 136.] =Construction.=--To trace the pit: 1. Lay off a line about ten feet in length perpendicular to the line of fire, to mark the foot of the interior slope of the epaulement. This line should be long enough to give the piece a field of fire of 90 degrees; mark the extremities and centre of the line with stakes or otherwise. 2. In the wings lay off two lines five to seven feet in length, making with the first line angles such that the trenches shall not restrict the field of fire or interfere with the recoil of the piece. 3. Complete the rectangle of the pit, and mark the points of intersection of the trenches and the ramps leading to it. 4. In soft ground it will be found to be more expeditious to use shovels; if the ground is hard, three picks and five shovels will be necessary for each detachment of eight men. The men should commence by breaking ground along the interior slope; having picked a breadth of about two feet, they face about and advance toward the rear of the pit. As soon as there is room the shovels follow the picks. In picking the men should be instructed to strike together to avoid accident. Under pressure this pit can be constructed in one and a half hours. THE GERMAN GUN-PIT. The German gun-pit consists of a rectangular excavation one and a half feet deep, with a ramp leading to it from the rear. The epaulement is formed like an ordinary glacis, and surrounds all but the entrance. This pit is easily and rapidly constructed, and, as seen from a distance, presents a very small target. The parapet being the same height all round, the gun can fire in any direction by widening the pit, which would then take the form of a semicircle. =Construction.=--1. Lay off a line four yards in length perpendicular to the direction of the line of fire. At each extremity erect a perpendicular of four yards. 2. From the vertices of the right angles thus formed lay off one yard on both the front and side lines, and mark the four points so determined, together with the rear extremities of the sides, with sabres or stakes.