THE NEW AUSTIN AN El ELI) GUNS. 
7 
exchange the copper plate (a, Pig. 6), the pressure of the spring upon the 
stop is relieved, and the block drawn out until the stop falls into the second 
groove (s, Pig. 5), when the spring is again allowed to act, preventing the 
block being drawn out further than is necessary for the purpose required. 
If the block has to be altogether removed, it is only necessary again to 
relieve the pressure of the spring on the stop and to draw out and remove 
the block. 
(C.) The Vent .—As already mentioned, this strikes the powder-chamber 
a little in front of slot. (Vide Pig. 2). Its position is perpendicular. 
The vent bush is of copper, in two pieces, the lower (which embraces the 
upper) being pressed up from the bore. The bottom (which projects 
slightly into the chamber) is rounded off. 
(JD.) Sighting .-*—This is similar with both guns. The length of the line 
of sight is one metre. 
There are two sights—a tangent sight and a screw foresight—both of 
bronze. 
lug. 7. 
(1) The tangent sight (Pig. 7) consists of a lower portion or socket,/; 
with its head, d, and of the tangent scale, a , with its cross-head, b. 
The socket fits into a hole bored in the gun on the right-hand top of 
breech end [k, Pig. 1), being there clamped by the screw, l. It is round, 
with the exception of a flat face cut on the right rear surface for a scale of 
metres, and another on the left to prevent still further, any lateral move¬ 
ment in the gun. 
The tangent scale, a , slides freely up and down in this socket, or lower 
portion, and is furnished with four scales. 
