The frame and ammunition having been brought into the battery, or to any other place, concealed either by trees or houses (for from the facility of taking new ground, batteries are not so indispensable as with mortars), the words “_Prepare for bombardment_” are given; on which the frame is prepared for rearing, Nos. 1 and 2 first fixing the chambers on the ladder; Nos. 3 and 4 attaching the legs to the frame as it lies on the ground. The words “_Rear frame_” are then given; when all assist in raising it, and the proper elevation is given, according to the words “_Elevate to 35°_” or “_45°_,” or whatever angle the officer may judge necessary, according to the required range, by spreading or closing the legs of the frame, agreeable to the distances marked in degrees on a small measuring tape, which the non-commissioned officer carries, and which is called--the Elevating Line. The word “_Point_” is then given: which is done by means of a plumb-line, hanging down from the vertex of the triangle, and which at the same time shews whether the frame is upright or not. Things being thus arranged, Nos. 1 and 2 place themselves at the foot of the ladder, and Nos. 3 and 4 return to fix the ammunition in the rear, in readiness for the word “_Load_.” When this is given, No. 3 brings a Rocket to the foot of the ladder, having before hand _carefully_ taken off the circle that covered the vent, and handing it to No. 2, runs for another. In the mean time, No. 1 has ascended the ladder to receive the first Rocket from No. 2, and to place it in the chamber at the top of the ladder; by the time this is done, No. 2 is ready to give him another Rocket, which in like manner he places in the other chamber: he then primes the locks with a tube and powder, and, cocking the two locks, after every thing else is done, descends from the ladder, and, when down, gives the word “_Ready_;” on which, he and No. 2 each take one of the trigger lines, and retire ten or twelve paces obliquely, waiting for the word “_Fire_” from the officer or non-commissioned officer, on which they pull, either separately or together, as previously ordered.