missive discharged from cannon afloat or otherwise, any desirable angle, and as such angle will cause said missive to be glanced or thrown off from said deck, that part of the vessel contained under the surface of said shield deck is protected from the effect of shot. Compare the displacement or space contained between the water line with that part of the inner surface of the vessel's side, and that part of the surface of the shield deck, at н, н, to that contained between the part of the water line and part of the surface of the shield deck, at K, K, K, drawing No. 1, and it will be seen that should the side be so pierced or torn by shot as to fill the first-named displacement or space, at H, H, with water, being all the water that can enter the vessel, will settle or be depressed proportionately to the weight of water contained in said space, leaving to the vessel the buoyancy occasioned by the greater displacement or space contained between K, K, K, less the weight of water, at H, H. The vessel cannot, therefore, be made to sink by the means aforesaid, and the steam-engine and machinery will be protected from ingress of water or shot. The water wheels of the vessel revolve horizontally under water; the wheels being cylinders or drums, м, to which paddles or floats are attached in any convenient manner. The wheels are placed in wheel cases or openings made in the sides of the vessel, and fitting the wheels as near as convenient. To avoid contact and friction, the water wheels should be made of metal, and consist of a hollow water tight drum, м, and floats, R. The wheels may be either fixed permanently or made to detach at pleasure, from a vertical shaft on and passing through the floor of the vessel into the wheel case or cases. In said floor, which may be made of timber or metal, in which a pedestal and stuffing boxes are placed, the first to support the wheel shafts in their position, and in which they also revolve, and the latter to exclude the water. The lower ends of said shaft, D, are in the shape of an inverted cone, or

bevelled with rounded ends, made of metal properly tempered, to diminish friction. The shaft end revolves in metal steps fixed in the bottom of the wheel openings or cases. The upper ends of said water wheel shafts connect to the steam-engine by a crank or wheel gearing. The middle parts, or drums, or cylinders, M, of the paddle-wheels are made hollow and water tight that they may be light and buoyant, so as to relieve their shafts from weight and friction, for which purpose some play should be allowed in fixing. When it is desirable to construct the paddle wheels so as to ship and unship, a circular ring of metal having a flange, and larger in diameter than the throw of the crank, should be bolted or secured to the floor over the wheel openings, embracing each water wheel shaft. On the flange is attached by screw-bolts and packing a cylinder, o; reaching in height above the water line of the cylinder; o, may be removed and placed out of the way when the operation of shipping and unshipping the water wheels is completed. The propelling wheels so fitted to ship and unship are attached to their shafts in the following manner, viz. :—In the drum, м, is a female screw with perpendicular grooves for the reception of keys, N, each of which is fitted with an eye-bolt on its upper end, so as to admit of their being drawn by an iron hook or otherwise, and rod, o, to the top of the cylinder, o, above the water line and replaced in the same manner. The water wheel shafts have a male screw, P, to correspond and fit the screw in the water wheel at м, and the operation of shipping and unshipping said wheels is thus performed. The engine is detached from the wheels by removing the connecting rod, or by throwing out the wheel gearing, the cylinder, a, is secured to its flange. The stuffing box is taken off, the pedestals are taken out, the shaft keys, N, are drawn, and the shafts are unscrewed and hoisted into the vessel through the cylinder, Q. The water wheels being detached, can readily be drawn from the wheel openings and hoisted

aboard, and another may be placed in the wheel opening; the paddle wheel will then rest on the bottom of the wheel opening. Let the shaft be lowered, and turn it till the end takes in its step, then till the wheel is clear of the bottom

of the wheel opening, and then key it. Let the pedestals, which will nearly exclude the entrance of water, be put in, then pump the water out of the cylinder, Q, and whilst placing the stuffing box, turn a cock, which may be placed in the lower part of the cylinder, a, through which any water passing the pedestals may run into the hold of the vessel, then detach the cylinder, o, and remove it and connect the engine.

The nature of that part of my invention which relates to my improved method of using the high-pressure steam-engine, by which additional power may be obtained, and the noise commonly produced by the escapement of the steam in its passage from the cylinder is avoided or lessened, consists in making a communication by means of a pipe between and from the escape-pipe or opening of the cylinder, to the centre of the upper part of the propelling wheel-case, encompassing the submerged wheel so that the escaping steam be conducted. within said case by the vacuum in part or in whole formed by the condensation of the steam at that place, and the centrifugal action given by the paddle wheel to the water contained within said wheel-case, which is made to condense the escaped steam; and for the better elucidation of this part of my invention, I refer to the accompanying drawing, marked No. 2, where one-half of the middle or cross section of a vessel with one paddle wheel and condensing-pipe or apparatus is represented, A, ^, ^, ^, is one half of the middle section of a vessel; B, B, the hollow cylinder or drum of the paddle wheel; c, c, the paddles or floats; D, the paddle wheel shaft; E, E, E, E, the case in which the paddle wheel revolves; F, F, F, F, F, the space between the paddle wheel and case; G, is the connecting-pipe or apparatus. The

escaping steam is made to condense and exhaust about the axis of the paddle wheel shaft, D, by means of the pipe, G, and the centrifugal action of the water caused by the paddle wheel induces frequent change of water in the pipe, G, and effects a partial vacuum within the escape-pipe and cylinder of the steam-engine, and the water contained within the case, E, E, E, E, E, condenses the escaping steam conducted to it through the pipe, G, or an air tight condensing cylinder may be placed over the exit passage, at G, the top of the cylinder standing above the water line, the pipe, G, terminating in it as at T. The condenser may be of any required dimensions; the water contained in it will present a refrigeratory surface. The centrifugal motion of the water in the wheel-case, caused by the action of the propelling wheel, will induce frequent change of water in the condensing cylinder.

I claim the application of shield decks to vessels constructed of metal or wood, whether propelled by steam power or any other power, and also the application of submerged propelling wheels upon the principle described in the aforegoing specification, whether placed vertically, horizontally, or obliquely, for the purpose of propelling vessels.

I also claim the method of using the steam-engine for the propulsion of vessels, by which the submerged propelling wheel-case or apparatus is made to serve as an exhauster or exhausting medium, and the water contained within the wheel-case, in which it revolves as a condenser, thereby conferring all the advantages of a condensing-engine with the lightness and simplicity of the high-pressure steam-engine, with also the noiseless action of the former.-In witness whereof, &c.

Enrolled June 15, 1842.

FRANCIS MARX.

199

Specification of the Patent granted to JOSEPH ATKINSON, of Round-hill, near Masham, in the County of York, Farmer, for Improvements in Thrashing and Winnowing Machines.-Sealed March 7, 1840.

WITH AN ENGRAVING,

To all to whom these presents shall come, &c., &c.My improvements in thrashing and winnowing machines consist in a novel arrangement of parts for effecting the operations of thrashing or separating corn from its straw, and also for winnowing or clearing it from its chaff and husks. The thrasher, or that part of the machine which strips or separates the grain from the ear and stalk, consists of a rotary drum or cylinder, furnished with any suitable number of spikes made of iron standing radially or nearly so round its periphery. This drum or cylinder is mounted in bearings fixed on the frame-work, and is partially enclosed or surrounded by a semi-cylindrical box or recess, the interior of which is also furnished with spikes standing in inclined positions.

Fig. 1, in the drawing hereunto annexed, represents a longitudinal section taken vertically through the middle of the machine.

Fig. 2, is a horizontal view, as it would appear when seen from above, some parts of the covering being removed to exhibit the interior.

Fig. 3, is an elevation or external side view, showing the manner in which the different parts are actuated by bands and toothed gear, and

Fig. 4, represents an end elevation of the machine, showing some of the internal parts, the same letters referring to similar parts in all the figures. a, a, is the drum armed with radial spikes, as before mentioned; b,b, is the semi-cylindrical recess by which the cylinder, a, is partially surrounded. The spikes fixed in this recess are