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of the Kent-road, in the Parish of St. George's South·wark, Engineer; for a new and improved Method or Methods of raising or producing Steam, for the Purpose of working Steam Engines and other Apparatus.

1

Dated April 3, 1819.

With a Plate.

To all to whom these presents shall come, &c. Now KNOW YE, that in compliance with the said proviso, I the said John Seaward do declare that the nature of my said invention, and the manner in which the same is to be carried into effect and performed, is described as follows; that is to say: I place a tube or combination of tubes made of cast-iron or any other proper material, of sufficient strength to resist the expansive force of the steam intended to be employed, in a furnace or furnaces (either horizontally, vertically, or otherwise as convenience may suit), and connect one end of the tube or combination of tubes with the working cylinder of the steamengine, or other apparatus as the case may be, by the nozle or steam passage, similar to a common boiler; to the other end of the tube or combination of tubes, I fix VOL. XXXV.-SECOND SERIES. B á small

a small feed pipe with a valve or cock and regulator, for the supplying the necessary quantity of water in a continuous stream, which being forced in, in due quantity, is rapidly converted into steam when it comes in contact with the internal surface of the heated tube or combination of tubes, and the steam thus generated will rush forward with uniform celerity, to perform its office in the working cylinder of the steam-engine or other apparatus to which it is applied; but it is necessary to observe that the heat should be so regulated that the water may not be decomposed when the apparatus is used with a low pressure engine. Although the tube or combination of tubes, both as to shape and size, and the mode of disposing them in the furnace or furnaces, may be varied many ways, I prefer a cylindrical tube of uniform diameter, passing backwards and forwards four or five times through the furnace in an horizontal position, which I call for the sake of distinction a salamander; and as represented in Fig. 1 (Plate I.) the upper part of the furnace being taken off to shew the situation of the tube; which for convenience is formed in five pieces connected together by flanges xxxx or otherwise; a the safety valve, C the end of the tube which is to be connected with the working cylinder of the steam-engine or other apparatus, z the regulator, g the feed-pipe; the parts of the salamander more immediately exposed to the action of the fire, I make stronger than those which are set in the brick-work, which is distinguished by being coloured red.

Fig. 2 is a vertical section of the salamander and furnace in direction from A to B, on the plan shewing the situation of the chimney tube b, the fire place C, and fire door d, and also the safety valve a. The flue bis surrounded by another tube or casing, for the purpose of

con

containing water for the supply of the salamander; this casing may be of sufficient altitude, so that the column. of water contained therein shall be of sufficient weight to supply the salamander without any other force; but in high pressure engines it would be inconvenient to employ a feed head of sufficient altitude, therefore the water must necessarily be forced into the salamander by a forcing pump, or by some similar contrivance; for although the water casing would be employed with considerable saving of fuel, it is not an indispensable part of the apparatus; and in the case of low pressure engines, the water from the air pump should be used for that purpose. The places shaded dark is the space for the fire to play round the strong tube or salamander.

Fig. 3 is another vertical section of the salamander and furnace, in the direction from C to D on the plan, across the fire-place C, shewing the fire bars eee, the safety valve a, and the branch f, to connect with the nozle of the working cylinder of the steam-engine.

Fig. 4 is also a vertical section of the same, in direction from E to F on the plan, shewing the end of the strong tube or salamander with the feeding apparatus, gg the feed pipe, communicating with the lower division of the water casing, h the stop cock, which is opened and shut by the handle i, being connected by a rod to the lever k, which is raised or depressed by the rising or falling of the piston m in the small cylinder /; this communicating with the interior of the salamander by the passage o o, the steam in the salamander will when too strong, or rather too much in quantity, arising from too considerable a supply of water, force up the piston, which shutting off the cock h, will of course diminish or stop the supply of water; the piston is forced down, either by a properly adjusted spring or by a

weight partially immersed in water, the specific gravity of the weight being rather more than that of the water; the cylinder will also answer the purpose of a steam guage and of a safety valve, for when the piston m is forced above the aperture n the steam will blow off. The conical plug p, which is regulated by the thumb screw q, iş for the purpose of casting the stream of water round in a thin sheet inside the tube, and when the engine is to discontinue working, the supply of water is to be stopped either by closing this plug or by shutting of the cock h. The water casing may be divided in two or more com- › partments or divisions, as r, s, t, in Fig. 2, and partially in Fig. 4, but communicating with each other by the pipes u, v; thus the pipe u connects the upper part of the division t with the lower part of the division s; in like manner the pipe v forms a communication between the two divisions r and s. By this contrivance the column of water will not be impeded from passing downwards, but there will be effectually prevented that rapid circulation which always takes place among the particles of a body of water when exposed to the action of heat, and by which every portion of the water acquires almost simultaneously the same temperature. The water in the lowest division, being nearest the fire, will be the hottest, while that in the upper division, supplied from the forcing pump, will be the least heated.

I do also raise or generate steam for working locomotive engines and steam carriages, and for other purposes where steam is required, by inclosing a mass of metal or other proper material; but I prefer cast-iron, previously heated to a high temperature, in a strong vessel sufficiently capacious and of any convenient form, and a stream of water being injected into the vessel upon the heated metal or substance, a volume of steam will be

generated