Reference has already been made to the _Shannon_, which was the first armoured cruiser of the British Navy. She was launched towards the end of 1875 and completed two years later. In substance she was a development of the idea which first found expression in the _Inconstant_, heavy armament being preferred to the protection of the guns. A narrow belt of armour with a maximum thickness of 9-ins. protected three-quarters of the water-line. This belt commenced at the stern and ended in a bulkhead some 70ft. from the bow. Forward of this bulkhead was an under-water protective deck, and a certain amount of armour was concentrated on the ram under water. The bulkhead, which was from 9in. to 8in. thick, rose to the upper deck, and afforded protection to a couple of 18-ton muzzle-loaders, capable of right-ahead fire. The remainder of her armament consisted of seven 12½ton guns, and was entirely unprotected. Other details of the ship are as follows:-- Displacement--5,390 tons. Length--260ft. Beam--54ft. Draught--23ft. 4in. Horse-power--3,370. Speed--12.35 knots. Coal carried--580 tons = nominal economical radius of 2,260 miles. The speed of the _Shannon_ was so low, even in those days, that it is a little difficult to surmise for what purpose she was designed, especially as this design was more or less contemporary with the re-designing of the _Dreadnought_.[6] It found favour, however, since she was almost immediately followed by two larger replicas, the _Nelson_ and the _Northampton_, details of which were:-- Displacement--7,630 tons. Length (between perpendiculars)--280ft. Beam--60ft. Draught (maximum)--26ft. 6in. Armour--Belt amidships, 9in. to 6in., compound: bulkhead ditto. Armour deck only, at ends. Main Armament--Four 18-ton M.L.R., eight 12-ton M.L.R., two above-water 14-inch torpedo tubes. Horse-power--6,640. Speed--14.41 knots. Coal carried--1,150 tons = nominal radius of 3,850 miles.