478 
ARMOUR-PIERCING PROJECTILES. 
One brand of P 3 was used (No. 112), with the exception of a few 
rounds fired witli Brands Nos. 137 and 143, and the charges were at 
first 
and afterwards 
2 Z 32-25 to 33 \ 
\*847 to ’840/ * 
The projectiles were studded and fitted with the Lyon gas-check in 
the R.L.,f and were all of the service form (9-in. Palliser shell, Mark 
IY.) They were all brought, by weighting with sand, to the required 
uniform weight of 268 lbs. 
They were fired directly at a range of 50 yds.; afterwards, to avoid 
injury to the Le Boulenge chronograph screen, at a range of 92 yds., 
against unbacked wrought-iron plates hung on supports by means of 
trunnions. These plates were 12 ins. thick, and 4 ft. square ; this size 
being found suitable to resist fracture on impact of shell. They were 
supplied by Sir J. Brown and Co., Atlas Works, Sheffield, and every 
care was taken to ensure uniformity of quality. Each plate cost 
rather more than £130. 
The velocity of each round was observed. 
The shells tried were of four classes—viz., chilled cast-iron, cast- 
steel, chilled cast-iron heads and cast-steel bodies, and forged steel. 
The chilled cast-iron shells were obtained from the following 
sources :■— 
1. Service shells from store. 
2. R.L. improved. 
3. Shells made of Gregorini (Italian) iron in E.L. 
4. Shells made by the Finspong Iron Company (Sweden). 
5. u Mr. Griison (Germany). 
6. „ Mr. Krupp (Germany). 
The cast-steel shells were obtained from the following sources i —• 
1. Landore Siemen’s Steel Company. 
2. Terre-Noire Steel Company (France). 
3. Messrs. Hadfield and Co. (Sheffield). 
The shells with chilled cast-iron heads and cast-steel bodies were 
obtained from the following sources — 
1. Messrs. Vickers and Co. 
2. Messrs. Cammell and Co. 
* The numerator of the expression in brackets gives the number of cubic inches per pound 
occupied by the charge when in the chamber of the gun, the denominator gives the gravimetric 
density of the charge, which must not be confounded with the actual density of the powder, 
f R.L. here and elsewhere in the paper stands for Royal Laboratory, 
