In the matter of armour this country owes a debt of gratitude to Sir John Brown, who made the Atlas Works at Sheffield famous throughout the world for the excellence of the armour-plates produced there. Indeed, the records of what he has accomplished seem to indicate that his rule was to surpass whatever his rivals produced, and never to forget that he might be able to learn something from others. His company took up the manufacture of chrome steel, which was patented in America about 1871. When the Italian experiments at Spezzia resulted in the 100-ton gun smashing, in 1876, 22 inches of iron armour and its backing, the French turned their attention to steel plates, as did also Sir Joseph Whitworth, but Sir John Brown thought that better results would be secured with iron plates with steel faces. These compound plates had half their thickness of steel. By 1888 the firm was producing compound plates each 32 tons in weight. An interesting comparison between French and English methods was made a few years ago[55] by M. Canet, of the well-known French firm of gun manufacturers, in a paper on the heavy naval guns and warships of the two countries. Referring to the latest type of the large weapons then employed at sea, viz., the English 12-inch gun, known officially as Mark IX., he described its method of construction, which has already been alluded to, and pointed out that the corresponding gun in the French navy was of 305-mm. bore (or 12.008-inch) and of 45 calibres in length. The barbette system of gun-mounting, as already explained, owed its origin to French inventiveness, and is preferred in the British Navy; but the French, curiously enough, seem to have preferred the English system of mounting turrets for the guns. The turrets themselves, however, differed from those of the English pattern, the French idea being to make them oval and smaller, so as to offer the narrowest possible target, and this theory was carried into practice even at the expense of the interior roominess. The limited dimensions, however, made it no easy task for artillerists to arrange conveniently inside the turrets all the machinery required, and M. Canet avowed a preference for the English practice of allowing the designer plenty of weight and room inside the turrets or barbettes. There were also structural differences in the methods of the two countries of arranging the armour, and it was claimed that the French oval form, with the other characteristics, had, among other advantages, that of distributing the blows of the projectiles over a greater weight of armour. Another important difference lay also in the method of working the guns. It has been the custom for many years in the British Navy to take up the recoil of the guns by hydraulic buffers, and to use hydraulic pressure to run out the guns again. The French introduced springs, which were compressed by the force of the recoil. Again, hydraulic appliances are preferred in the British Navy for training