By comparing the dimensions in this table with those of the three ships Given in a former table, it ap pears that the breadth of ships in proportion to their length is less in this table than in those which were built about the middle of the last century. The rela tive breadth of the Spanish ship appears to have been •then, as well as at later periods, the greatest in pro portion to the length; the relative breadth of the i:nglish ship in proportion to the length appears to have hecu considerably less than that of the Spanish, r.nd a little greater than that of the French ship. I3y the table also, it appears that the relative breadth of •Englisit ships in proportion to their length was in creased in the establishment of 1706 from the dimen sions of preceding establishinents, arid that tins rela tive increase continued with very little alteration till 1745. 'towards the end of the last century a decrease of their relative breadth was introduced, which has influenced most of the sun bseq(ten, designs. The I,rcadtlr of the largest ships, by the establishment of f 745, varied from ! ° to 755 the length; at the pre sent time, the breadth of most of our line of battle ships is within tire limits of 3G° and 36'; by which it appears that tire relative breadth of our- line of battle ships is considerably less at present than it was at that period.
The proportional breadth which should he given to ships is very materially affected by the cotisi(leration of' the number anti weight of the guns which they are intended to carry; as the greater the number of guns, and the :,cater their weight, tile more is the stability diminished by the greater elevation of the centre of gravity of the ship, which must he counteracted by a corresponding increase of hreadth. The best disposi tion of force as to the calibre of the guns to he used on board different ships, is a very difficult subject, and particularly requires, Mn-. \Iorgan observes, the opinion of experienced and scientific naval officers for its dcterrnination. it appears to be generally admit ted, that the effect of large shot is much more des tructive than that of a greater number of smaller shot, making together the same weight. The limit to which the size of the guns on board ship may be carried with advantage, is hounded by the consideration of the number of Bands required to work them, the con venicnce of handling the shot in action, the strain brought on the beams and ship's sides by their weight, and the effect they produce on the stability of a ship. The height of the guns above the water influences ve ry materially the stability; and while particular atten tion should be paid, that the lower tier should be at a sufficient height to use the leeward guns under all circumstances in which they may be required, the tipper tiers should he kept as low as possible.
The establishment of guns in I757 and 1762, di rected in the first rates, 42-pounders on the loner deck, 21-portnders on the middle (leek, and I2-pounders on the tipper deck. The establishment of 1792, di rected 32-pounders on the loner (leek, 2.4-pounders on the middle deck, and 18-pounders on the upper deck. It appears that 42-pounders have been considered too heavy for use on board ship. The large line of battle ships of the Americans carry long 32-pounders on the loner deck, short 32-pounder's on the upper deck, and 32-pounder carrouades on the quarter (leek, waist, and forecastle. The advantage proposed by
this disposition of force, is the great weight of metal of a broadside, and the prevention of mistakes in the size of the shot in action. The principal force of large ships being chicly required in general action, and at short distances, the short 32-pounders and the earronades are adopted as glt log a very efficient farce. The total weight of metal of a broadside of an English 120 gun ship is 1520lb.; the weight of metal of one of these American two decked ships, carrying grins in the waist, is 160011). The English first rate has thus the appearance of a greater force than it possesses, from tke smallness of the weight of metal of many of the guns. 'l'o concentrate the weight of metal appears desirable, not only as preventing incor rect col rpar•ison, but as giving the most efficient force, and as affording the means of keeping the weight of the guns low.
The most important consideration respecting any proposed disposition of guns, is to place the lower tier- at such a height as to be at a sufficient distance from the load-water-line, and to give the ship such breadth as to ensure a proper moment of stability.
The advantage of dividing the ships of the royal navy into as 1'ew classes as the different services would admit, has been fi•eqnently recommended as very de sirable, particularly as relates to the appropriation of stores and ;ear. Experience may eventually deter mine the classes, into which the royal navy might be advantageously divided. Such a division must, how ever, always be subject to alteration from previously unforeseen circumstances; such, for' instance, as the adaptation of steam vessels to the purposes of war, Etc. Ships of three decks might probably be confined to one class, haying a little greater breadth, and a little more height froth the loner deck to the load-water- line than our present first rates. Ships of two decks may also probably he confined to one class. carrying 84 guns, as our present ships Ganges and Asia, with a little increase of breadth. Frigates might, perhaps, be confined to two classes, the larger carrying 60 guns, of about the same length as our present frigates of this class, and of a greater breadth; and the small er class of 46 guns, of nearly the same length and breadth as our present frigates of this force built af ter the Leda. The present 28 gun frigates are gene rally considered a bad class, having too great a height above the water in proportion to the part of the body below; the same defect which the old 80 gun ships with three decks, and the 64 gun ships with two decks possessed. This cannot be fully corrected without their dimensions being so considerably increased, as to render it questionable whether their expense might not be too great for their relative utility. A large class of corvettes, similar to sonic built in America, carrying 24 or 26 guns, might in many services substi tute these small frigates, and be a powerful and use ful ship in the service. Our corvettes of 18 guns fully substitute the 18 gun brigs, found too large for their rig, and arc useful vessels for general ser vice. The present 10 gun brigs, which are found good sea boats, might be the last class. These se ven classes, with cutters and other small craft, might probably constitute advantageously the royal navy.