THE ROYAL ARTILLERY INSTITUTION. 
137 
to its final conical form, with a rim, and tapped with a screw on the inside 
to G.S. gauge; it is then soldered into the head. (The bush and head 
are heated for this operation; and after soldering it is washed in a ley of 
soda-ash and water, to remove superfluous acid.)* * * § The firmness of the 
junction is tested by hammering the socket. 
Bullets .—Are of mixed metal, 4 lead to 1 of antimony. There are 28 
of 18 to the lb., and 35 of 34 to the lb.f 
Felt or Kamptulicon Bing .—This is simply a ring of the material men¬ 
tioned (soaked in kit composition for the 7, 9, and 16-prs.) 
Assembling the Shell. 
This operation consists in putting together all the component parts of the 
shell. The tin cup is dropped into the recess in the bottom of the shell, the 
diaphragm—with an iron tube temporarily screwed in—is next inserted (the 
tube keeping the place for the gun-metal tube and tin socket), brown paper is 
placed round the sides of the shell to keep the resin from adhering, the lead 
and antimony balls are inserted, the iron tube removed and the gun-metal 
one screwed in, the resin run in, and the felt or kamptulicon ring inserted; 
the wood lining of the head is placed over the washer. The head, having 
the gun-metal bush soldered in, is now put on. 
The shell is now placed in a screw-press, and pressed together. It is 
essential that the wood head should be pressed firmly down on the felt disc. 
The rivets are placed in the twisting-holes, and the head riveted on to the body. 
The shell is taken out of the press, and the holes for the screws tapped, and 
the screws—four in number—placed in, J the heads of screws and rivets filed 
off flush with shell. The body and head are further connected by a ring of 
solder.§ The shell is placed in a lathe, and the solder evenly turned down. 
They are next trimmed, gauged, and painted. The gauging is the same as 
given for common shell, except that the thickness of shell is not gauged at 
this stage, and a gauge is applied to test the correctness of screw for primer 
in the tube; this gauge also ensures a proper length being left for fuze. 
The body of the shell is painted black, and the head red. || 
Royal Laboratory, 
February 1875. 
* A metal socket, contracting at the lower end to fit into the tube (except in the 40-pr., 
where it fits on the outside), and tapped on the inside for the primer, takes the place of the gun- 
metal bush and tin socket in all calibres above the 40*pi\, inclusive. 
f Mixed metal bullets, varying in size and number, are used for all B.L. shrapnel, and for M.L. 
shrapnel up to 80-pr., inclusive; sand shot are used for the 7-in. and upwards. 
J The heads of the 7, 9, 16, and 40-prs. only are attached to the body in this manner. 4 screws 
are used in the 7 and 9-prs., 6 for 16-pr., and 8 for 40-pr. Plain rivets are used for the 64-pr. and 
upwards. 
§ At this stage, 64-pr. shells and upwards are placed in a lathe, and the extractor holes bored in 
the head, and afterwards bushed with tin, the bushes secured with solder. 
|| The heads of the 7, 9,16, 25, and 40-prs. only are painted red; all other calibres are painted 
black. 
