2. Commence excavating at the interior crest, throwing the earth to the front and sides (being careful to allow a berme of about one foot), thus forming an epaulement 1 foot 6 inches high and 10 feet 5 inches thick at bottom, extending round to the front corner of the lateral trenches. Then throw the earth out to the side front to form mounds about 4 feet high in front of the lateral trenches to still better protect the detachment, sufficient space being left in front for an embrasure. Dig down two feet throughout the pit back to the line 10 feet from the interior crest and level off the bottom. Slope up from the bottom of the pit at ten-foot line back to the eighteen-foot line. If desirable to connect adjoining pits of this class, extend the lateral trenches until they meet. Time of construction of pit complete in all its details, with detachment of eight cannoneers, gunner, and chief of section, in stiff clay, without previous practice, one hour and twenty minutes. ORDINARY RUSSIAN GUN-PIT. This type differs from the gun-pit proper, in that the wheels rest on the natural surface of the ground, the side-pits being for the cannoneers. The only apparent advantages are good cover for the detachment under heavy fire, drainage as far as the piece is concerned, and facility for ingress and egress. The obvious disadvantages are contracted space for working party in digging, contracted field of fire, and the mark presented by the embrasure to hostile fire. =Construction.=--Lay off on a line perpendicular to the probable direction of fire 10 feet, prolong the line 5 feet 3 inches in both directions, and mark the four points thus determined with stakes or sabres. At the middle point of the ten-foot line erect a perpendicular to it and lay off on this perpendicular to the rear 9 feet 2 inches; through this point determine a parallel to the ten-foot line and lay off on it, on both sides of the perpendicular, 9 feet and 14 feet 3 inches, marking the four points so determined with stakes or sabres. The parallelograms whose vertices are thus established fix the surface-lines of the lateral trenches. Dig down to 4 feet 6 inches for the bottom of the trenches and throw the dirt to the front and side, giving the epaulement a height of 3 feet, and leaving space for the embrasure in front. When time permits, cut outside and rear steps for the trenches, as indicated, to admit of quick egress for the gun detachment. [Illustration: FIG. 140.] Time of construction complete, soil and detachment same as English pit, two hours. GENERAL OBSERVATIONS ON GUN-PITS. In forming the epaulement, leave a berme of at least a foot; and, when there is time, level and ram the earth, which, in front of the muzzle, should not be more than three and one half feet above the bottom of the pit. If there are side trenches, the earth in front of them should be high enough to afford complete protection to the men occupying them.