nearer forward than aft, which will consequently make the fore body more full, will best answer every purpose, especially that of velocity.

And, although it is plain, that by so doing, the entrance of the ship will be the more full, and will present, apparently, more absolute force against the current of water than when the midship bend is placed nearer to the middle of the ship; yet, by moving that bend nearer to the fore end of the ship, the body will decline horizontally so much the quicker, and part of the effect of that resistance caused by the lateral pressure of the water will be taken off; which must, certainly, be of more service to the velo. city than what is lost by making the fore part of the ship somewhat fuller; and seems to promise the connection of capacity and velocity, the two great objects to be pursued in the construction of ships' bodies.

And we may now venture to assert, upon the premises which we have adduced, that, by carrying the midship bend forward, we shall gain not only in point of velocity, but likewise in point of steerage, which will be a double advantage.

In addition to what has been already said with regard to the sailing trim of a vessel, in the first section of this chapter, it may be observed, that, however advantageous it may be thought for a vessel to sail on an even keel, yet, in the opinion of many persons, the extreme breadth of a ship should always be higher abaft than in midships, by about one sixth of the load draught of water; which, in consequence, will make the ship draw more water abaft than afore. The reason assigned is, that, as the fore part cannot so readily divide the water, when the keel is parallel to the surface as when it is inclined to the stern, the vessel will sail better: and this is the general opinion of seamen, who have frequently remarked, that it is necessary to make her draw more water abaft than afore; whereby they, at least, gain this advantage, that the ship will answer her helm better: but, it will, in construction, occasion the decks to be raised higher abaft than afore.

That the extreme breadth should also be raised considerably more afore than abaft, is recommended for these reasons:-when a ship is close hauled by the wind, and lies much over, the weather side will lose much of the breadth; whereas, on the contrary, the lee side will gain considerably; the ship then displaces a greater quantity of water on the lee side, and, according to the manner in which fluids act, should be supported with greater force, and, of consequence, be able to carry the greater sail. Hence, it is plain, that, by raising the breadths, we keep them as a reserve to be used when a ship stands most in need of relief, that is, when she lies most over.

It may here be remarked, that flat-floored ships do not require their breadths to be raised so high afore and abaft; because, carrying all the weight of their cargo low, they are thereby made capable of carrying a greater stress of sail.

The several excellencies and defects which we have pointed out, as above, may be constantly seen existing, in a greater or less degree, in the several classes of shipping which compose the naval force of Britain, as well as of those which are employed in carrying on the commerce of the country and its intercourse with foreign states. Our first-rate ships in general, especially those of greatest stability, are admirable ships in every respect; as they sail well, and combine almost every good quality. Large

as they are, they are perfectly manageable; and their evolutions are ge nerally made with wonderful facility.

OUR SECOND RATES, or rather, our ships of ninety guns, have, too generally, those defects in their construction which contribute to instability : arising from want of that capacity which most of the first rates possess; and, having it, have the chief corrective against instability in three-decked ships, wherein the centre of gravity is necessarily very high, and their form the least calculated to derive lateral support from the effort of the water.

EIGHTY-GUN SHIPS were formerly constructed so as to carry their guns upon three-decks; and they were found, in consequence, more dispropor tionate in their parts, and less useful, than any other large ships in the service. Their topsides were so high above the water, to admit of having three tiers of guns, as to be out of all proportion for the length and breadth; nor could the lower ports be fixed at a sufficient height above water to admit of their being opened in blowing weather, even if not very rough; we admit, that the heights between decks and depth in the waist could not be much less than those of a ship of 100 or 90 guns, but must still observe, that they could not be duly proportioned in the water; that is, could not be brought down to that depth which would be found the best sailing trim, if properly constructed.

Ships of this description must therefore labour under many disadvantages, arising from their disproportionate height, even if their principal dimensions were similar in every other respect to those of ships in general. It were useless to enumerate all these disadvantages, because the defects which we have described are generally known and acknowledged. That eighty-gun ships of this class will be continued in the navy is not probable; and we have, therefore, no farther occasion to notice them in our work.

The ship of eighty guns upon two decks is, on the contrary and altogether, the most useful and valuable one in the service; and it is, with the enlarged seventy-four, of which we have herewith given the draught and dimensions, deservedly esteemed as the most perfect in the navy; and as possessing, to an eminent degree, all the properties of capacity, stability, and swiftness.

As two-decked ships, inferior to the seventy-four, are often required for expeditions and convoys during war, and as flag ships on foreign sta. tions during peace, the sixty-four-gun ship has sometimes been used for these purposes. This ship has also frequently taken her place in line of battle. In the latter case her force has, however, been frequently found incompetent; the seventy-four, of which the French line is chiefly composed, being incomparably superior; and, in the former cases, the fiftygun ship would equally answer, and at a still less expence. The latter is a very useful ship, although defective in its proportions; for, as its guns are carried upon two decks, the height and breadth are too great in proportion to the length. We have had, notwithstanding, several favourite ships of this class.

THE SIXTY-FOUR gun ship may be considered, in relation to the seventy-four, as the ninety to the first rate; possessing the same defects, without compensatory qualities; and its continuance is, by no means, desirable. in the navy. This is a truth acknowledged by the practice of our adversaries as sixty-fours have, for some time past, been disused in the French service.

FORTY-FOUR GUN SHIPS, constructed to carry their guns upon two decks, are as disproportionate in their parts as any other ships in the service. Being exactly on the same principle as the eighty-gun ship of three decks, the observations upon that apply directly to this. Nor is it generally used in battle. We may therefore also reject this as unworthy of farther notice.

Directly the reverse of this is the frigate constructed to carry forty-four guns upon one deck; the most powerful and most valuable of our frigates. That of which we now speak, rated as of forty-guns, may be so constructed as to have all the qualities which can possibly be united in one ship; for, having but one deck, the height may be in due proportion to the length; and, in consequence thereof, there will be required no more than a proportional breadth, by which she may be brought down in the water to that depth which is allowed to be the best sailing trim for ships in general. Here then is no obstacle to prevent her being duly qualified in point of velocity. Her dimensions, also, being greater than those of the forty-four with two decks, enables her to carry heavier metal, which must, consequently, render her a formidable ship. Hence it is, that this frigate may be ranked as the most valuable frigate of the English navy.

The frigates of thirty-eight and thirty-six guns are very little inferior in point of proportion and utility to the forty-four (rated as forty). As their force is less, they consequently require a smaller number of men, a less quantity of provisions, and are more readily equipped. The frigates of thirty-two guns are well proportioned; and, of course, equally estimable and useful. In short, our frigates, in general, are excellent cruisers; they sail well, and are remarkable for stability. These from thir ty-six to forty-four guns upon one deck are, indeed, admirable: and the whole, together with our sloops of war, are highly eminent for their superior qualities.

As merchant-shipping, in general, is scarcely divisible into distinct classes, we cannot speak of it with that degree of precision, as of those of the royal navy; because their respective forms and dimensions are dependant, almost entirely, on the local practice, or the ideas of their respective constructors; and fluctuate accordingly.

The merchant-ship of 330 tons, of which the plans and dimensions are herewith given, is peculiarly adapted to the West India trade; and has been found to answer so well, that several ships have been built from the draught.

PRACTICAL RULES

FOR THE

CONSTRUCTION OF SHIPS, &c,

CHAPTER I.

GENERAL OBSERVATIONS AND DEFINITIONS.

TH HE first step towards building a ship. from design is, to construct draughts for that purpose, namely, plans and sections drawn with all possible exactness, examined by proper calculations, and fit to be submitted to the most accurate scrutiny.

Of these, the principal are; first, the SHEER DRAUGHT, or plane of elevation, upon which the whole length of the ship is represented, according to a side view, perpendicular to the keel, as upon a section supposed to be cut by a plane passing through the middle line of the keel, stem, and stern-post. (See Plate I.)

Secondly, the BODY PLAN, or plane of projection, in which the ship is exhibited according to an end view, so as to present the outlines of her principal timbers, and shewing the projection of her frames relatively to each other. It is supposed to be described on a vertical section, at the midship bend, or broadest part of the ship, perpendicular to the sheer plan, and comprehends a delineation of the shape of every frame timber in the ship.

Thirdly, the HALF BREADTH OF FLOOR-PLAN, supposed to be described by an horizontal section cutting the whole body of the ship, lengthwise, at the broadest place on each timber. On this draught, which is generally placed under the sheer draught, are described all the sections or curves that may be imagined to cut the ship horizontally, lengthwise, &c. In this draught the curves of the transoms, called the Round-Aft, are also marked, and sometimes the breadth and thickness of the timbers. It is called the Floor-Plan, as being that on which the whole frame is supposed to be erected, and as exhibiting the upper side of the keel, with all the floors, &c.

To the above may be added, the draughts exhibiting the DISPOSITION of the FRAME TIMBERS and PLANKING; the profile of the INBOARD Works, or interior of the ship; the PLANS of the DECKS, &c.

From the foregoing definitions it may readily be conceived, that the Sheer Draught determines the length and depth of the keel; the difference of the draughts of water; the length and projection, or rake, of the stem and stern post; the position of the midship and other frames upon

the keel; the load water and other water lines; the wales; the dimensions and situations of the ports; the projection of the rails of the head and stern gallery, with the stations of the masts and channels.. That the Body Plan limits the different breadths of a ship in various points of her length, and exhibits the outline of the timbers respectively to each other, as they are erected upon the keel, with a variety of sections of the ship in different parts of her length, and always perpendicular to the surface of the water; so that the eye of the observer, when placed in what may be properly termed the longitudinal axis of the ship, may perceive the several sections at one glance; that is to say, when looking full on the stem, from before the ship, he shall distinguish all the fore timbers, or those in the fore-body; and, when looking from behind, directly on the stern, he shall perceive all those of the after-body. But, as the two sides of a ship ought to be exactly alike, it is judged sufficient to represent the sections of the fore part of the ship on the right side, and those in the after part on the left side, so as to perceive all the sections, as well afore as abaft, upon one plane.

With respect to the horizontal plane, or Half Breadth Plan, it may also be observed, that, when a ship floats upon the stream, it is evident that her upper works will be separated from the bottom by the surface of the water, which will accordingly describe an imaginary horizontal line upon the bottom from the stem to the stern-post.

The most elevated of these lines is that, called the load water line, which is supposed to be drawn by the surface of the water on the upper part of the bottom when she is fully laden.

If the ship be lightened of any part of her lading, and preserves the same difference in her draught of water at the two ends, or so as to preserve the same equilibrium of the keel with regard to the surface of the water, another line may be delineated upon the bottom, close to the surface of the water, which will be a second water line, parallel to the first, but nearer to the keel in proportion to the height which the ship has risen. Thus may a variety of water lines be drawn parallel to each other and to the load water line.

The construction of these, and of the other lines described on the three principal draughts, will be more fully understood by the following definitions, &c. which may be considered as supplementary to those given.

The HEIGHT of BREADTH is, as before explained, the main breadth or broadest part of the ship, and is defined by two curved lines, called the Upper and Lower Height of Breadth Lines, as heretofore described.

The MAIN HALF BREADTH is a section, supposed to cut one half of the ship horizontally at the height of breadth. It comprehends, therefore, the broadest part of the ship from the middle line to the outside of every timber.

The TOP-TIMBER LINE is a curve which generally terminates the height of the ship amidships, and also describes the sheer; it is likewise where the top-timber half breadth section, described beneath, cuts the ship fore and aft, or lengthwise.

The TOP-TIMBER HALF-BREADTH is a section of one half of the ship, supposed to cut the ship horizontally at the height of the top-timber line.