THE EOYAL ARTILLEKY INSTITUTION. 
8 
with the intention that each plate should be a unit capable of combination 
with others. These plates, in accordance with the Committee’s recommenda¬ 
tion, were tried at Chatham in August, 1860. They were found proof 
against bullets fired by the Lancaster carbines of the Royal Engineers at 50 
yds., and subsequently against Enfield rifle bullets at the same distance; 
but on suspending them in front of an embrasure many pieces of the bullets, 
some large, but the greater part small, found their way between them, and 
between the plates and the parapet, glancing off the plates as they swung 
from the blow. These splinters were sufficient, in the opinion of the officer 
who conducted the experiment, Major Lovell, ILE., to have made the 
part of the battery immediately adjoining quite untenable. On inspection 
of a canvas screen set up at 5 ft. to the left, to catch the splinters, it 
appeared that scarcely any of them diverged more than 2 ft. at that 
distance; consequently, men standing round the gun at a greater dis¬ 
tance, from the parapet would have been safe, and if there were a traverse 
adjoining, the next gun detachment would also be safe. The result rather 
points to the necessity of a mode of suspension which will not permit the 
splinters to penetrate, or the necessity of a lateral projection to catch them, 
than to a rejection of iron plates on this account. 
Another mantlet of the same material, furnished by Captain W. L. 
Yonge, R.A., D.-A.-A.-Gen., was tried at Woolwich in July, 1860. It 
was 4 ft. by 2 ft., and ^ in. thick; weight 100 lbs. 6 oz , or 12^ lbs. per 
square foot. It was perfectly bullet-proof at 10 yds.; but on repeating the 
experiment with a plate of T 3 S -th inch, weighing 71 lbs. 12 oz., or 9 lbs. per 
square foot, it was penetrated at 25 yds., shewing that nothing less than 
J in. homogeneous iron will give the complete protection desired. 
6. Price’s Case-hardened Wrought Iron. —Mr G. Price of Wol¬ 
verhampton called the attention of the Committee in May 1860 to the effect 
of case-hardening on iron, and forwarded a plate \ in. thick as a sample. 
His object, however, was rather to form the armour plates of ships of this 
material than mantlets. On trial this \ in. plate proved perfectly bullet¬ 
proof, and was scarcely indented at 10 yds., but various fine cracks gave 
reason to suppose that if reduced to the same weight and thickness as the 
other irons employed it would have had less resistance; and this view being 
sustained by mechanical tests in the Eoyal Gun Factories the material was 
not recommended. 
Millard’s Mantlets. See Article 14. 
7. Captain W. L. Yonge, E.A., D.-A.-A.-Gen., forwarded in December, 
1859, five plates of tempered steel made by Bessemer’s process, each 2 ft. 
by 4 ft., and of various thicknesses, from 0'0625, or -^th inch, to 0Y0, or 
-j^th inch, and weighing from 3'51bs. to 4*5 lbs. per square foot. He 
forwarded at the same time an equal number of plates of annealed steel 
by the same makers, varying in thickness from (L05in. ( ¥ ^th) to 0T25 in. 
(ith); and in weight from 3*6 lbs. to 4*75 lbs. per square foot. His inten¬ 
tion was to combine these thin plates in pairs, with an interval between 
them, and they were tested with the following results :— 
