6 
THE NEW AUSTRIAN EIELD GUNS. 
( B .) The Breech Bloch (Figs. 5 and 6).—This is also of bronze-steel, and 
rectangular. The front and back faces are plain, but the latter not parallel 
to the front face, but slightly inclined. Along the upper and under sur¬ 
faces run a projection and deep groove (like a rabbet), ensuring, together 
with the ribs, l , a perfect fit when the block is home. 
The loading cylinder {h, Figs. 5 and 6) is also of bronze, cylindrical, and 
dovetailed into the breech block as shown, so as to be capable of movement 
backwards and forwards. Square-headed projections from this cylinder are 
acted on by the studs, ff (which grip them), as these studs pass along the 
groove, r, when the breech block is pushed home or withdrawn. 
To make a perfect gas-tight joint with the Broadwell ring in the end of 
the powder-chamber, the breech block is furnished with a copper plate 
( a , Fig. 6), which has on the back six holes, any one of which will fit over a 
stud in the hollow cast in the block to receive, the plate. The position of 
the plate in the block can thus be altered in case of wear at any particular 
portion. This plate is further dovetailed into the block, and secured from 
any movement of translation by the screw ( f Fig. 5), which passes through 
from the rear face of the breech block, into which its head is countersunk. 
To the left end of the breech block is attached the arrangement for 
moving it, and for securing it in position. This consists of the plate 
(g, Fig. 5), secured by the screws [hh, Fig. 6), through which passes the 
spindle of the square-threaded screw (i, Fig. 5), which carries the cross 
handle ( K , Fig. 6) at the outer end. The thread of the screw, i, is so cut that 
when the handle K is horizontal, no part of the thread projects beyond the rear 
face of the block, and the latter can be moved laterally in the slot until this 
thread comes opposite the female thread cut for its reception in the rear face 
of the breech-block slot; a half-turn of the cross handle (bringing the same 
vertical) then causes the screw to bite and sends the breech block well home. 
The cross handle is of iron, covered with leather. In order to prevent it 
(and so the screw, i) moving when not required to do so, it is secured in 
one or other of the two necessary positions by means of a catch (m o, Fig. 6), 
acted on by the bent spring ( n , Fig. 6). The catch pivots on the screw, 
h , and has on the underside two noses, p and q , sliding in a groove running 
partly round the exterior of the axis of the screw (as shown in Fig. 5). The 
spring, n , is secured by one of the other screws, h , and is so arranged that 
w T hen it presses down the nose, q , of the catch, the handle is retained in the 
vertical position, the screw 7 being home in the gun, and the breech-block so 
secured in its place. A slight pressure on the long arm, o, of the catch 
overcomes the spring and releases the nose, q, when the handle is free to 
move until it becomes horizontal, when the spring presses on the second 
nose, p, and secures the handle in a new position. As the thread of'screw 
is now withdrawn into the block, the latter can be moved outwards (towards 
the left), and when the loading is completed, the arm, o } is again pressed 
and the movements reversed, and so on. 
In order to control the amount of movement of the breech block in the 
slot, two grooves (r and s, Fig. 5) are cut in its upper surface, into which 
the end of a stop fits, which is pressed down by a spring. As a rule, this 
stud or stop fits down into the groove, /■; the length of w T hich only allows of 
the breech block being withdrawn until the loading cylinder (Fig. 5) 
comes opposite the bore. In case, however, it be necessary to examine or 
