TRANSACTIONS OF THE SECTIONS. 181 
we have briefly to notice some of the improvements and changes that have taken 
place in the construction of ordnance and the art of defence, and to chronicle some 
of the most important results which have placed the whole of our naval and mili- 
tary armaments in a state of transition. It is now well understood that His Majesty 
the Emperor of the French was the first to apply iron plates as a defence to the 
sides of ships, and that ships of war protected with a given thickness of plate 42 
inches were invulnerable to shot or shell. For a considerable length of time this 
opinion was prevalent, and was acted upon both in this country, France, and Ame- 
rica. The experiments instituted by the Admiralty and War Office have, to a great 
extent, dispelled these notions; and it has been proved that a smooth-bored Arm- 
strong gun, with a150-Ib. spherical shot, can pierce a43-inch-thick plate and 18inches 
of teak. In fact, it has been proved by experiment that no vessel yet constructed 
“is able to carry armour-plates of sufficient thickness to resist such powerful ordnance 
as has been brought against them. 
Every effort has been made on the part of the Government to determine experi- 
mentally the properties of iron best calculated to resist shot, and the greatest pos- 
sible care has been observed, both in a chemical and mechanical point of view, to 
secure the yery best description of iron for that purpose. All these facts have been 
ascertained, as also the penetrating powers of different descriptions of ordnance as 
compared with the thickness of the plates to be pierced. In this position the 
balance of force to the resistance of the plate was in favour of the gun, but with 
this qualification, that the gun had to sustain an explosive force of powder equivalent 
to one-third the weight of the shot, a charge which the gun was unable to bear. 
Under ordinary circumstances, with the usual charge of one-eighth the weight of 
the shot, it might reasonably be inferred that the balance was on the side of the 
plate, and that guns of such heavy calibre were insufficient in strength to sustain 
these tremendous charges of powder. Again, it must be borne in mind that these 
results were only produced at certain distances, and under certain conditions of 
heavy charges of powder and a short range of 200 yards. 
The inquiry was thus hanging on the balance, when it was determined to ascer- 
tain the effect of the large Horsfall gun of 22 tons weight with a charge of 75 lbs. 
of powder and a 300-Ib. shot, against a target representing the ‘ Warrior,’ with her 
18 inches of teak and 43 inches of iron. The result of this experiment was the 
penetration of the mass, with a huge opening in the side of the target upwards of 
2 feet in diameter. This experiment is probably not calculated to apply to ships 
of war carrying ordnance of such immense weight, but it is greatly in fayour of 
forts, where an enemy’s vessel may be struck at a distance of 1000 yards. 
Passing from the Horsfall gun, we now come to the last and most important 
experiments with the Whitworth gun: the first was a 12-pounder field-gun, and » 
the second a 70-pounder naval gun; both of the guns were rifled. These experi- 
ments are very instructive, and I probably could not do better than quote from the 
‘Times,’ of September 18th, a statement of the effect produced by these guns:—- 
“Tt will, perhaps, be remembered that a decided difference was established very 
early in the controversy between the penet eae powers of solid shot and those 
of shell. Solid shot at one time failed, and at another time succeeded, against 
armour-plates, according to the modified conditions of the experiments; but shells 
failed absolutely and invariably. No shell could ever be driven through even a 
moderately thick plate of iron, and it was concluded, therefore, that this, the most 
dangerous and dreaded species of missile, could undoubtedly be kept out of a ship 
by a thin casing of armour. 
“ Accordingly, as a reduction of a ship’s armour to the least possible weight was 
of great consequence, especially in small vessels, gunboats and other craft of the like 
description have been built in some countries with 23-inch or 2-inch armour-plates, 
and considered effectually shell-proof. On Tuesday, however, Mr. Whitworth 
entered the field with two of his pieces, for the service of which he had specially 
prepared some flat-fronted, hardened shells. The 12-pounder, at 200 yards, presently 
sent these shells through a 2-inch plate backed by a foot of timber; from which 
simple piece of evidence the conclusion is inevitable, that vessels protected to that 
extent only are shell-proof no longer. 
“But in the trial of the 70-pounder an additional result was obtained. It has 
