160 
THE FRENCH FIELD GUNS. 
The breech-closing arrangement for the three different guns varies 
only in dimensions and in some trifling details. 
It consists of the steel screw (a), working in the centre of the tube 
and interrupted in three places, and of the door (b), through which the 
screw works. The door opens sideways, and is so arranged that the 
screw can be withdrawn from the prolongation of the bore, which is 
then left clear for loading, &c. 
The handle (h) and the crank (k) are for working the screw. There 
are three guides, which work in channels in the plain portion of the 
breech-end of the gun. 
The working is very simple. 
To open the breech, -J- of a turn is given to the handle and crank. 
This movement makes the threaded sections of the breech-screw corres¬ 
pond with the plain portion of the breech end of the gun; it also 
frees the spring catch, which closes again automatically after the com¬ 
pletion of the movement. The breech-screw is then withdrawn as far 
as possible, and, with the door through which it works, is turned on 
one side. The gun is now ready for loading. To close the breech, 
bring the breech-screw into the prolongation of the bore, push it in as 
far as possible, and give £ of a turn, which engages its threads with 
those of the breech-end of the gun. The catch again acts automati¬ 
cally, and the safety arrangement keeps the breech firmly closed. The 
obturator (obturateur de champignon de Bange) is somewhat peculiar. 
It consists of a steel mushroom-shaped head (p), with a cylindrical 
shaft (q), fitting into a channel bored through the breech-screw. It can 
turn in this channel, and is capable of a slight backwards and forwards 
movement. It is prevented from falling out by a screw-pin, working 
in a channel round its shaft. Between the head of the obturator 
and the breech-screw is the packing ( s ), consisting of asbestos and 
grease, enclosed in strong linen, kept together by two tin cups, and 
strengthened by metal bands in front and rear. 
When the gun is fired the pressure upon the mushroom-head (p) 
forces out the packing, which by its radial expansion closes the bore 
to the escape of gas. 
The 80 mm gun weighs 425 kils. (937 lbs.) 
. 90 mm „ 530 „ (1168 lbs.) 
i, 95 mm „ 700 „ (1543 lbs.) 
The projectiles for the 80 mni and 90 mm guns are common shell, 
shrapnel, and case. The 95 mm gun has, in addition to these, a double 
shell. 
The cartridge bags are of amiantine cloth. The powder is of large 
grain, each grain measuring G’S 111111 (about \ of an inch). 
The charge for the 80 mm gun is T5 kils. (3*3 lbs.) 
„ « 90 mm „ 1*9 „ (4-2 lbs.) 
„ „ 95 mm „ 2*1 „ (4-6 lbs.) 
The iron body of the shells is slightly thicker near the head (its 
diameter at that point being only of an inch smaller than that of the 
bore of the gun). The object of this is to centre the shot during its 
passage through the bore. 
