THE NEW AUSTRIAN FIELD GUNS. 
A copper bush is screwed into the breech end of the powder-chamber, for 
the reception of a copper Broadwell ring (k Fig. 2, and section Fig. 4). 
This ring forms a gas-tight joint with the face of the copper plate (a, Fig. 6) 
of the breech block. 
The front inner face of the breech-block slot (7i, Fig. 2) is at right angles 
to the axis, but the rear face is slightly inclined. The upper and lower 
surfaces are symmetrical as to the axis. From the latter project the ribs* 
( 'll , Fig. 2), forming a run or groove, r, between them. The ribs serve to 
guide the breech block, and the slot, r —as we shall see—affects the loading 
cylinder ($, Figs. 5 and 6) by means of the studs, ff, projecting from the 
latter. 
Over the right-hand opening of the slot for breech block is secured by 
screws the so-called breech-block cover, for protection of the projecting 
portions of the breech block from dirt and damage. The covering is 
completed by means of a leather cap. 
Near the left side a vertical slot is bored through the metal of the upper 
surface of the gun and into the slot, through which the stop pin or studf 
(vide next page) is passed into a groove on the surface of the breech block, 
so as to prevent the latter being withdrawn too far. 
Fig. 5. 
Tit 
* These ribs are portions of the thread of a large-pitched screw, 
f In the German field guns, the removeable steel vent answers the same purpose. 
