C H A P. V.

OF THE PARTICULAR CONSTRUCTION OF THE BOATS; AND
THEIR APPLICATION TO VARIOUS SITUATIONS.


	However novel the formation of the boats may appear, at first sight, I hope to be able to exhibit reason for the particular mode of constructing them: I therefore bed the accurate attention of the reader to this part if the combination, as on this especially I conceive the whole system of small canals is supported.

	I have already assigned reason for the boats being small; I have also hinted at the necessity of their passing speedily over the machinery: I must again repeat, and impress this consideration, that the trade being divided into small portions, will, consequently, create a number of movements at the machinery; it is therefore necessary, that such movements should be performed with the greatest possible expedition, in order that an important trade maybe transacted. 

	In deliberating on this part of the operation, I found it would be the means of great loss of time, if the boats were to be placed on any kind of carriage, or cradle, for the purpose of passing the plane; that such carriage or cradle would also prevent one movement on the machinery, which is the great means of expedition; hence, to prevent loss of time, and that the boats might come prepared to pass the plane, I was necessitated to compose the plane of rollers, or to give wheels to each boat:  after weighing these two modes of construction, I ultimately determined on wheels to the boats. Rollers being attended with many seeming difficulties, first, that of forming them in a straight line, secondly, that of keeping them true: thirdly, should any rollers be out of repair, the machinery and trade would be stopped, for so long a time as the repairs continued in hand. But, if a boat was damaged, that boat only could be retained till repaired, which quickly be done, in consequence of being light, and easily handled. 

	Having therefore adopted wheels, I shall endeavor to obviate such objections as seem most natural to arise against this combination of a boat and wagon, after describing their mode of  formation. For this purpose, see PLATE I. which represents three modes of constructing boats to convey different articles, either by a flow, or by a quick movement, as particular circumstances may require.

	Fig. 1. Exhibits the Market, or passage, boat. 
	Fig. 2. The dispatch for the purpose of conveying such goods as require expedition. 
	Fig. 3. The common trader. 

	This last boat is twenty feet long, four widem two feet ten inches deep, in the clear; flat at the bottom, and ends like a box; it may be composed of three-inch deal, bolted and screwed in the usual mode, and stayed at the corners; with two knees, or ribs, inside, exactly above the wheels, and about five feet from the ends, which will leave ten feet in the center.

	Two keel of scantling, about six inches square, and eighteen inches asunder, must be laid along the center of the bottom to receive the wheels; or is this is not found sufficient, a framing, of the same dimensions as the bottom of the boat, may be built, which will be sufficient to support the weight while she is out of the water.

	The wheels, which may be from fix to ten inches in diameter, are to be two feet distance from the extremities; and may be cast, axle and wheel, in one piece, and turned at the shoulders; or a wrought iron axle if necessary, which axle may move on brass or iron steps. 

	The wheels being thus small, and short in the axle, will lie close under the bottom of the boat, secure from the possibility of touching the sides of the canal, or receiving injury; the keels, or platform, which compose the bottom, being cased with thin board, will cover every thing but a part of the wheel rim, as represented at A. B. The chains on the end are for the purpose of hooking the boat to the leading chains of the inclined plane. In regard to objections which may be suggested against the formation of this boat, I conceive only three can arise.

	First,  The diameter of the wheels being small may occasion some additional friction, in passing the machinery.

	Secondly, The possibility of the wheels being injured. 

	Thirdly, The resistance on the water, in consequence of the wheels, and shape of the boat.

	To the first it must be observed, that, while the boat is out of the water, it will ever act on a regular plane of cast iron, and never be subject to inequalities, and although the friction will be something more in consequence of the small wheels, yet, as sufficient power may be obtained to raise her, the friction arising from their small diameter will be no considerable impediment.
	
            To the second, I conceive the wheels are not subject to receive injury, but while the boat is out of the water; and, even then, I do not perceive wherein they are liable to damage; the wear which ensues by a long course of time, only, can affect the boat in this part; and, to this, it must be observed, that she will not undergo so much hardship in passing two hundred miles, as a common wagon in moving one mile on the useful roads. But, even admitting frequent repairs should be necessary, small slips may be constructed at proper situations, where a man, by a common windlass, would draw the boat out of water, and repair her, with the same facility as he would remedy a defect in a cart, or a wagon; the process of dry docks necessary to large boats, is by no means required in repairing these.

	In the third objection, the resistance in the water may appear to arise from two causes; first, from the projection of the wheels in some degree from the he bottom; and, second, from the flatness of the boat on the ends. But it must be observed, that boats of this construction are designed to move slow, consequently the resistance arising from the particular construction will be very trifling, and of little importance, resistance being much more in proportion to the velocity, than either shape or weight.

           To give a general idea of this, it is merely necessary to remark, that should a man attempt to drive a horse sixty miles per day, he could scarce convey a boat of the lightest construction at that rate; yet the same horse would convey one hundred tons twelve miles per day with ease, and arrive at the end of sixty miles in five days which is equal to twenty tons per day moving through the whole space of sixty miles.

          This I hope will be sufficient to show that resistance from shape, in flow movements is inconsiderable; also, that the true principle of conveying goods cheap, when expedition is not required is, to move flow and take a quantity; and in this respect I shall now consider their superiority over boats of twenty-five tons.

          Seeing that the true principle is to move flow and take quantity, in the usual trade, it must be observed that a twenty-five ton boat is a limited quantity, and more cannot with propriety be applied to the boat, consequently he must resort to speed, and combat the resistance. 

          Two twenty-five ton boats cannot be hooked to each other; as the helm of one will not govern the other, and they are too ponderous to be managed by a boat-hook, they are also so long that, in making the bends in the corners of the canal, they separate the fluid by side pressure; the bow of the first separates the fluid, for instance, to the right, and the stern repels it to the left; which agitation consequently will retard the motion of both boats: hence, on a canal for twenty five boats, one boat must be the allowance of one horse; he cannot have more; but must endeavor to accomplish quantity by speed, and encounter the consequent resistance.
 
         But of the four ton boats, ton, fifteen, or twenty, may be linked together, to compose any weight which is thought proper, according to time and distance being only twenty feet long they incline to the bending of the canal like the links of a chain, and follow in the wake of each other, being guided by a man walking on the horse-path with a boat-hook , hence, by the system of small boat, a horse may take any quantity, and move with a proportionate velocity. 
 
          From boats of this construction, another material advantage arises to proprietors of collieries, lime, delphs, &c.;  frequently a canal may pass near such works; and yet it is inconvenient, or inconsistent, with the quantity of trade, to extend the water level to the very spot; which circumstance frequently obliges such proprietors to construct rail-ways, and keep wagons, which they must be at the expense of first loading, before they can deliver the commodity to the boats, and frequently of forming a deposit on the canal banks from whence they must again load into the boats. But if such works lie above the canal, and not more than six hundred yards distant, so that a regular descent could be obtained; a single road might be formed, and the boat floating on additional wheels might be raised to the pit by the steam-engine employed in pumping, or by the mode described by D. in the Plate of Parts.
	
	But if such a regular declivity could not be obtained, supporting the ascent was easy, the boat, on a carriage prepared for the purpose, might be conveyed to the works, anywhere within a mile, by a horse: there taking in her cargo, descend from thence to the canal, and be immediately ready for navigation.
	It may also be advisable, in some cases, for the proprietor to reduce his boats to two tons, being twenty feet long, two feet six inches wide, and the same depth; by placing wheels on these boats, of the same dimensions as those of four tons, the will pass the same machinery, and navigate wherever canals so adapted extend; and the advantage to the proprietor would be, that such narrow boats would pass through a tunnel, not more than three feet six inches wide and nine feet high, which may be constructed so cheap as to enable him to drive a water level into the center of his works: so far relates to the square ended, flow mover, and common trading boat.
	
	But as various circumstances may require dispatch, such as boats to market, passage boats, or quick communications between trading towns, where valuable merchandise may require speed; figure the first and second, represents boats for this purpose, being constructed thirty feet long, four wide, two feet ten inches deep; flat at bottom, with wheels as before mentioned, and sharp at the bow, as speed is required, containing from four to five tons: in building these boats stern posts must be raised about five feet high (as in the Plate), to which the chains are fixed; thus, the chains being raised will prevent the leading chains of the machine from pressing on the goods, or incommoding passengers. Of the operation of these boats I shall treat in Chapter the Seventh, on the System of Navigation.