Our Navy List tells us that we have something like eight hundred ships of war, including in round numbers sixty iron-clads. These figures given in this way of course require some explanation. In the list are included gun-boats, tenders, store-ships, tug-boats, old wooden ships which are really waiting to be broken up, training-ships, and wooden guard-ships stationed at various ports. Our fighting navy really consists of the iron-clads and the unarmoured cruisers built for high speed; to these we may add gun-boats of a recent type built to carry one very heavy gun. And with regard to the iron-clads it must be noted that even they are not all fitted to take a place in line of battle. Many of them are ships built from 1861 to 1864, having very thin armour, comparatively light guns, and we fear in many cases worn-out boilers. The _Warrior_, our first real iron-clad man-of-war (for we can hardly count as such the floating batteries), was launched in 1861. She was built on the lines of a fast sailing-ship, and has none of the heaviness of form which was unavoidably given to most of her successors. When she was launched, armour was still in the region of doubtful projects, and it was considered a remarkable success to give her four-and-a-half-inch plates on her central portion only, for the ends were wholly unprotected. The _Warrior_ too was an enormously long ship--no less than three hundred and eighty feet from stem to stern; but even this length was exceeded in the sister ships _Northumberland_ and _Minotaur_. These ships are neither strong in armour nor handy in manœuvring; they have of course their uses, but they cannot be compared with the later ships constructed when we had acquired some practical knowledge of what an iron-clad should be. As soon as it was recognised that rapidity in manœuvring--in other words, power of turning easily and certainly--was a necessary quality of a good iron-clad, ships were built much broader in proportion to their length; and this facility of manœuvring was further increased by the general introduction of the twin-screw; that is, the placing of two screw propellers one on each side of the stern-post, each being independent of the other; so that one or both can be used to drive the ship; or one can be reversed while the other continues driving ahead; thus enabling the ship to turn as easily as a boat when the oarsman backs water with one hand and continues pulling with the other.