It may occur to the reader to ask, Why not have sea-going masted vessels at once? To which it may be answered, first, that the masted ships must inevitably draw more water than those of which the _Cyclops_ and _Hecate_ are types. Turret-ships like the _Monarch_, or broadside-ships like the _Hercules_ and _Sultan_, draw about twenty-five feet of water; the smaller ships only sixteen, while at the same time they are more heavily armoured. Thus the latter, if close pressed by an enemy's sea-going ironclads--the only class from which they have much to fear-- could take shelter up a river out of their reach. In action near the land these monitors, moreover, could be handled with greater ease. Secondly, from their much smaller size, the coast-defence ships are built at a much less cost--an important consideration in days when a first-class ironclad costs about as much as a small fleet of bygone days. The vessels we have been describing are of rather more than two thousand tons burden, as compared with the five thousand tons of the larger sea-going ships; and, speaking roughly, the expense of construction is proportionate to the tonnage. The _Glatton_ turret-ship has several characteristics in which it differs from the above class of monitors. It has but a single turret, and its guns throw six hundred pound shot, carrying three miles and a half. Her water-draught is about six feet more than that of the _Cyclops_ and _Hecate_, and her armour-plates three inches thicker. Though she carries fewer guns, the _Glatton_ is a much more powerful vessel than the other monitors. (Note: The above description of English monitors is adapted and abridged from an article in Chambers's Journal.) We shall now briefly describe the _Devastation_, one of the largest and most powerful of all our ironclads. The _Devastation_ in her after-part rises but four feet and a half above the water; but to meet bad weather she is furnished with an armour-plated half-raised forecastle, so that forward she is nine feet out of the water. The free-board amidships is still higher, being at this point level with the platform on which the two turrets are placed. In the centre of the ship rises a circular iron erection, on the top of which is the hurricane-deck. Through this structure runs a passage, in which are situated the entrances to the hatchways and to the hurricane-deck overhead. From the hurricane-deck rise the ship's two funnels; and here also are the captain's fighting box, already alluded to in describing the coast-defence ships, the fire-proof shield for protecting the steering gear, and the boats. In a gale the hurricane-deck is the only safe place in ships of this kind--the only place where one would not get speedily washed overboard. As for the below part of the ship, it is there almost impossible to breathe, even when air has been pumped in from above, which is the only means of ventilating this portion of the vessel.