THE EOYAL ARTILLERY INSTITUTION. 
369 
turn of tlie rammer-head required with other projectiles is omitted with 
case shot. 
After the gun is loaded No. 3 lays, No. 4 assists him at the.trail, enters 
the friction-tube into the vent and fires; No. 5 supplies ammunition 
and hands cartridges and projectiles to No. 1 and friction-tubes to No. 4. 
In loading the first round only, No. 1 fetches cartridge, projectile, and 
friction-tubes. 
With reference to taking out ammunition from the boxes, it is to be 
remarked, that generally speaking two cartridges and projectiles are to be 
taken out of the boxes by No. 5, taking care that the projectiles as far as 
possible are from the boxes on the right and left of the mule alternately. 
In quick firing, three cartridges and projectiles may be taken at once. 
When the ground is such as not to admit of the gun recoiling, before 
opening fire the recoil-ropes are fastened to the wheels to check the 
recoil. 
Tor this w purpose Nos. 8 and 4, on their respective sides, unhook the 
front end of the recoil-rope from the advance-hook, pass the rope round 
one of the felloes of the wheel and attach the ring at its end to the hook 
on the opposite end of the rope: the hook end having been pulled through 
the ring at the trail of the carriage sufficiently for that purpose. 
Unloading . 
14. To unload a gun loaded with common or shrapnel shell, No. 2 
enters the rammer into the bore up to the projectile, then turns the rammer 
to the left; by this means the nose drifts on the projectile are caught by 
the slots in the rammer-head. No. 2 then withdraws the projectile from 
the bore, turning the staff slightly to the left. 
The easiest and quickest way of unloading case shot is to lower the 
muzzle of the gun, if necessary raising the trail. The ring on the cover of 
the case shot may be got hold of by the worm, and in this manner the 
projectile extracted. 
Cartridges are invariably unloaded with the worm. 
Lading. 
The trajectories of projectiles fired from rifled guns. 
15. In order to explain the principles .on which the laying of rifled 
guns is founded, it is necessary to devote some short considerations to the 
trajectories of their projectiles. As further, the interior construction of the 
projectile has an influence on the trajectory; we will first speak of the 
trajectory of the common shell, subsequently of those of other shells. 
Trom the description of the ammunition we know that the gun has two 
sorts of cartridges, one for low-angle fire with a large charge, the other for 
high-angle fire with a small charge. Common shells are fired according to 
circumstances with the low or high-angle cartridges. The axis of the gun 
may either be horizontal, or inclined upwards or downwards to the horizon* 
When the gun is fired the common shell is set in motion by the force of the 
