THE ROYAL ARTILLERY INSTITUTION. 
207 
ct Two solid shot of the same metal (i.e. homogeneous iron) and very slightly in 
excess in weight to the cast-iron ones, and fired with precisely the same charge, 
completely penetrated the plates, with scarcely any injury to themselves, clearly 
showing the value of this description of metal for penetrating iron plates, and that 
much of the work was expended in the destruction and dispersion of cast-iron shot.” 
Tig. 4 is from a photograph of a 12-pr. Whitworth shot rig. 4. 
which was fired on this occasion, taken after it had pene- |Pf§| 
trated 3" of iron. The Eeport states :— Jj, ij|| 
“ The three homogeneous metal projectiles.were so slightly 
changed in form as to present the same appearance as they did before ||| IBS 
use, and they could all have been fired again from the same gun.” |||fISw 
This shot is now in the specimen room of the Ordnance 
Select Committee in the Arsenal. 
Numerous experiments with steel shot were made during the year 1863. 
In February of that year some steel shot were manufactured by Messrs 
Makin, of the Attercliffe Works, Sheffield, and were fired from a 40-pr. 
Armstrong rifled gun, and a 7" Armstrong B. L. rifled gun, the latter at a 
“ Warrior” target, and the former at 34" unbacked plates, both at 200 yds. 
range; the 110-pr. shot remained in the target, and when subsequently 
removed were found to have penetrated about 7*5 // , being “ set up” about 
an inch; the 40-pr. shot penetrated the 3\" plates and broke up. 
The report on this experiment states : 
“ The quality of the steel used in these two shot (110 lbs.) is a marked improve¬ 
ment on those formerly produced by Mr Makin; but they do not come up to Mr 
Whitworth’s shot in toughness or temper.” 
And as regards the 40-pr. shot which all penetrated the 3plates, the 
Committee observe:— 
“ A good 3 “ plate has always stopped a 40-pr. cast-iron shot, with more or less 
damage to the plate, according to its quality; so that, allowing for the inferior 
quality of the plates used on this occasion, yet as they were 3 %' thick, it 
demonstrates the advantage there is in having shot of great hardness and tenacity.” 
The next comparative trial which was made of cast-iron and steel shot 
was in March 1863, when a steel shot 994 lbs. in weight was tested in 
comparison with a cast-iron shot of 66 lbs. w r eight; they were both fired 
from a 7" Armstrong B. L. rifled gun at a “ Warrior” target, 16 lbs. charge 
being used with the cast-iron shot, and 14 lbs. with the heavier steel shot, 
the terminal velocities being 1461' and 1178' respectively. The following is 
an extract from the report on this experiment: 
“A comparison of No. 560 and No. 562 shows the superiority of steel overcast- 
iron shot in consequence of the great amount of loss arising from the breaking up 
of the latter; for although the work* in No. 560 (a cast-iron shot) was 2,199,773 foot 
lbs.,f the damage to the plate was only an indent of 2‘45 // ; whereas, in the case of 
No. 562 (a steel shot) although a less amount of work was stored-up in the shot, 
* The quantity of work carried by a shot is --—, 
where W= weight of shot in lbs., 
F=its velocity in feet per second, 
g being the force of gravity=32^. 
f A pressure of one pound exerted through a distance of one foot. 
[VOL, IV.] 
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