420 
MINUTES OF PROCEEDINGS OF 
The weight of the finished gun is 22 tons, 18 cwt. 
The gun was built up to the 5th course, inclusive, in the manner ordinarily 
practised at Elswick, being turned in the lathe after each course was added, 
to the proper size for the next course; but the three outer courses were put 
on without moving the gun from the contracting pit, being accurately turned 
and bored to dimensions calculated to allow for the alterations due to the 
contracting process. This was an important step in the progress of 
manufacture of built up guns, because their size ceases to be limited by the 
power of machines when their various parts can be finished separately and 
then built up into the complete gun in one place by simple superposition. 
The 600-pr. gun is rifled on Sir William Armstrong's shunt principle 
with 10 grooves, having a depth at muzzle of * * * § 08", and a twist of 1 turn in 
65 diameters. 
The projectiles are provided with brass studs *85 in. diameter, flattened 
sideways to about *65 // , in ten rows of five or six each to run in the rifle 
grooves. The studs are fixed into the projectiles by being stamped into 
shallow undercut holes. 
The segment shell carries 510 segments averaging 6 oz. each, packed as 
in the 12-pr. segment shell, but in two rows instead of in one. The bursting 
charge is 15 lbs. 
The common shell is about 30 in. long, and carries a bursting charge of 
from 45 to 47 lbs. of powder. 
The steel shell carries a bursting charge of 24 lbs.,* and is closed by a 
hollow cast-iron plug in front, so that on piercing plates the powder takes 
effect forward. 
The 600-pr. gun was commenced in May, 1862, and delivered in 
March, 1863.t 
This gun was mounted on a garrison sliding carriage weighing 54 cwt., 
with special platform weighing 75 cwt., having a slope of 3J°, and with raised 
iron racer 18 ft. 9 in. long to the stop. 
The rifle projectiles on the ground were as follows :— 
A. Cast-iron solid shot, with hollow eonoidal head. Length 25*1 in.; mean weight 610 lbs. 
B. Cast-iron solid shot, flat-headed. Length ; mean weight^ 
C. Cast-iron common shell, eonoidal head. Length 305 in.; mean weight 556lbs.; capacity 
42-5 lbs. 
D. Steel shell, with cast-iron hollow round head or cap. Length of body 19*7; mean weight 
688lbs.; capacity 16lbs.§ 
All these projectiles were fitted with soft gun metal studs to take the 
rifling. 
There were also spherical cast-iron and steel shot, diameter 13*235, 
weight respectively 304 lbs. and 342 lbs .; of these one cast-iron shot was 
fired at the end of the day. 
* The powder being driving with setter and mallet, and a mixture used of F.G. and L .G. powder—• 
one part F. G. to three parts L. G. 
t For the foregoing particulars of construction and dimensions, I am indebted to G. W. Rendel, 
Esq. 
£ Not known. 
§ Filled with L. G. powder well shaken down in the common way. 
