100-pounder), furnished with 155 rounds each. They are two-deckers, carrying two tiers of batteries. Both vessels are not completely protected. They are iron-cased at the waterline and over the whole of the spar deck; but beyond this no parts but their guns are protected. Their distinguishing feature is that they have a ram or spur, which, like a hatchet, projects under water from the line of armour plates of which it forms part. The ram is made of steel, and its weight is 12,000 kilogrammes: it projects about six mètres, or nearly 20 feet in the form of a hollow cone, with two long pieces like the neck pieces of a helmet, which fit the bows. No part of this spur-like prow is less than 12 centimètres, or 4½ inches, thick.
The Couronne is a 40-gun frigate of a peculiar model. Her form and dimensions differ from those of the preceding iron-clads, being more rounded at both ends, and more shapely to the eye. Her length is 80 mètres; breath 16 m. 70 c.; her average draught, 7 m. 60 c.; displacement, 6,076 tons; height of her tier of guns, 1 m. 98 c.; her engines, 900 horse-power. She carries 650 tons of coal, which maybe increased to 1,000. What distinguishes the Couronne is that her hull is of iron, constructed of plates 2 c. thick. The armour plating is fastened on the side by ribs and angle plates, the spaces between being filled with teak of 28 c, upon which rests a covering of iron of 3 c, separated by a teak backing of 10 c. from the armour plates, which have a thickness of 10 c. at the water-line, and 8 upon the top sides. The defensive armour thus consists of a double thickness of wood of 38 c, and a triple thickness of iron at the water-line of 13½ c., including the skin of the ship. The system of protection was tried at Vincennes in 1857, and gave satisfactory results as to its solidity.
The Normandie is similar in construction to the Couronne. She is the first iron-clad that ever crossed the Atlantic, having been to Mexico in 1862. The dimensions of the Normandie are — length at the load line, 253 feet 6 inches; breadth, 55 feet 3 inches; draught, 22 feet 9 inches; height of battery, 5 feet 8 inches; displacement, 5,600 tons. The length of the ship is therefore less than five times the breadth. The Normandie is armoured round and round on the wood plank and frame of the ships with 4½ inch plates. The Normandie carries an armament of 36 cast-iron rifled 32-pounders, or 4 guns less than the Couronne.
The Invincible is an exact reproduction of the Normandie. She is, like the former, a 36-gun frigate, her guns being of the calibre 30, which corresponds to the 100-pounder of Sir William Armstrong. Her engines are 900 horse-power nominal. Her length at the waterline is 78 mètres; breadth, 17; she draws 7 m. 75 c., the height of her lower tier being 1 m. 82 c.; and she is provided with 155
