A series of coast-defence monitors was decided upon in deference to public clamour, and the first of these, the _Glatton_, was begun in 1868, and finished in the latter part of 1870. She was intended to be for coast-defence purposes only, and not an ocean-going ship in any sense of the term. Consequently her coal capacity was small, and she was very heavily armoured. She had but one turret, and this was so disposed that as the vessel had no masts the turret could be turned to give the guns a range of fire all round except for a small section astern, only about 20 degrees being thus uncovered. Although her design was admittedly founded upon the American monitor type, several important improvements were introduced. The American monitors had shown on several occasions that a heavy shot striking near the base of the turret was liable to cause the turret to jam or become unworkable. To render this impossible in the case of the _Glatton_ she was equipped with a heavy breastwork built outside the base of the turret, in such a position that the lower part of the turret was absolutely protected and consequently could not be disabled, while if a shot were to strike the upper part of the turret it would do little damage. The _Glatton_ had a freeboard of only 3 feet; the hull was plated with iron 12 inches thick above the water-line, and 10 inches thick below it, and behind this was a teak backing 20 inches thick, and behind this again two thicknesses each of 1 inch of iron forming an inner skin, while the frames to which this was attached were no less than 10 inches deep, and were only 2 feet apart. Altogether the sides of this vessel were 3 feet 8 inches in thickness. The turret contained two 25-ton guns; its armour was 14 inches thick in the most exposed parts, and 12 inches thick elsewhere. And besides this it had a wood backing of 15 inches, and an iron inner skin ⅝-inch thick. It was 30 feet in diameter, and similar to the turrets of the _Captain_ and _Monarch_. The breastwork rose 6½ feet on each side of the vessel from the upper deck, and was plated with 12 inches of iron, with a 15-inch backing of teak. The upper deck had a sheathing of 3 inches of iron. The total length of the vessel was 245 feet, its breadth 54 feet, and it drew 19 feet of water. It was of 2,700 tons burden, and the engines were of 500 h.p. nominal. Its bunkers were designed to carry 250 tons of coal, but its ballast tanks were so designed that if necessary they could take another 250 tons of coal. With such dimensions and such a weight of armour to carry, she was, of course, a slow vessel, but in regard to her fighting power it was estimated that she would give a good account of herself against even such a vessel as the _Monarch_.