appear to be the fact, an engraving shall hereafter be given for the purpose of making it better known.

The general construction of the press is claimed, as is the particular mode in which the levers are to operate; the iron cheeks with the slot between the bars which compose them, and which allow the driver to be drawn down by the levers; the application of the stirrup and driver are also claimed.-Ibid.

For an Improvement in Canal Boats. THOMAS W. BAKEWELL, Cincinnati, Ohio, August 25.

THE object proposed to be accomplished in the improved canal boat, is, to fix an awning above the roof or top of the cabin, which awning may be lowered to admit of passing under a bridge. A patent for a contrivance for the same purpose was granted to Jacob Bromwell, of Cincinnati, on the twenty-third of June last, and is noticed at p. 274. The support of the roof or awning, as described by the present patentee, is to be constructed of light pieces of timber, so framed and jointed, that they may double down upon the permanent roof, upon the principle which regulates the approach of the two sides of a parallel ruler, as will be seen by the claim, which is "the application to canal boats of the forementioned principle, which principle is that on which the parallel ruler is made, and by which a rectangled parallelogram may become a rhomboid, and vice versa, the sides remaining unchanged.'

It is proposed, as in Bromwell's patent, to render the awning self-acting, by a projecting piece, properly fixed, to strike against the bridge, and press the framing down; it may also be made to rise spontaneously by a weight acting over a pulley, or by other means.-Ibid.

SPECIFICATIONS OF AMERICAN PATENTS.

Specification of a Patent for some Improvements in the Boilers of Steam Engines. Granted to ANTHONY HERMANGE, Baltimore, Maryland, November 26, 1828:

To give a sufficient description of my improvements in steam boilers, it will not be necessary to enter into an account of steam boilers now in use, as they are, of course, very various, and well enough known to distinguish them from my modes of construction. The boiler itself, with regard to its outward contour, I will make of any convenient shape. As convenient a one as any will be to have it of a cylindrical form, or of that of a parallelopiped; or this last surmounted by a half cylinder; or of a prism, whose base is a hexagon; of a cubical, or indeed of a variety of forms. I will place the fire-place, and flue, and fuel-pipe, (where I have

one especially for that purpose, particularly when the fuel to be used is coal,) inside of the boiler, disposing of them in such a manner, that when the proper quantity of water shall be in the boiler, they shall be below its surface. This will secure the advantage of having the water almost entirely to surround the fireplace, flue, and fuel-pipe, where this last is employed. The flue, particularly, shall be lengthened out inside of the boiler in a variety of ways, in order that it should present an extensive surface in contact with the water, and that the heat evolved in the fire-place, should thus, by means of the heated air freely circulating through the lengthened flue, be all, or nearly all, communicated to the water before the flue passes out of the boiler. The flue will, in this manner, have an effect somewhat analogous to that of a reverberatory furnace. I said the flue may be lengthened out in a variety of ways; it may, for example, go from the fire-place perpendicularly upwards for some way, then form an arch, and return vertically downwards, and have its exit from a convenient place in the lower part of the boiler, or thereabouts: this would be one of the simplest methods. After ascending as before, the flue may have a tortuous or spiral disposition downwards, and have also its exit as before. The main flue may also, above, be divided into two, three, four, or more smaller flues, as convenience may dictate, and these again may be connected together in the bottom part of the boiler, or towards the bottom, for their exit from the boiler, by a single flue or more; from the fire-place the flue may have a serpentine form in the boiler, and have its exit at any convenient place. In fact, it will readily be perceived that a variety of modes may be adopted. The fireplace I will construct of any convenient form, and place it in any position that the easy introduction of fuel, or any other such circumstance shall require. It may, for instance, be placed at the bottom of the boiler, with a grate opening into a wind-box below the boiler; in this way the fuel-pipe may communicate from the side of the boiler, at an angle from the horizon, sufficiently inclined to permit the fuel to fall with facility into the fire-place, This would be an excellent disposition when the fuel to be used is coal; a coal-receiver, with two sliders or doors, may thus be adapted to the outside end of the fuel-pipe, in order that, at the instant of supplying fuel to the fire, the heated air in the fuelpipe may not be suffered to escape. When the fuel is to consist of wood, it would, no doubt, be better to have the fire-place opening, for the reception of the wood, on the side of the boiler, or the end of it, by means of a door a little above the bottom of it, so that the water may also come in contact with the bottom of the fire-place. In this way, also, there may be practised, if convenience requires it, an opening through the bottom of the fireplace, (across which a grate may be placed, through which the ashes may drop,) communicating with an opening through the bottom of the boiler, which may there have a wind or blast-box

attached to it. It will be perceived that the arrangement may be various. As in the combustion of the fuel, with regard to boilers in common use, much of its inflammable substance passes off in the form of dense smoke, &c., without entering into a perfect state of combustion, I will employ bellows (conveniently adapted for the purpose, and which may, of course, be worked by the engine itself,) for the purpose of keeping up a constant current of atmospheric air through the ignited fuel, and to keep up the current of air thus heated throughout the course of the flue. As the air, in approaching towards the exit of the flue from the boiler. will become cooler, and, of course, from its increased density be of less volume, it will be well, ordinarily, to diminish the flue gradually as it approaches its exit. I will avoid bringing the fuel-pipe (where one is used), or the flue into that part of the boiler occupied by steam, for the following reason: the fuel-pipe and flue, having a direct communication with the fire-place, would, of course, always be filled with air intensely heated, which would be extremely likely to keep them in a red hot state; in this condition, being in contact with steam, a constant decomposition of portions of the steam would take place; its oxygen combining with the metal would rapidly corrode it, to the evident danger, after a little use, of the bursting of the boiler; whilst hydrogen gas would be extricated, during the progress of decomposition, which might interrupt the free and secure motion of the rest of the machinery of the engine. For the purpose of ascertaining always the height of the water in the boiler, I will make use of any description of water-gauge that may be adapted to ordinary steam boilers: a very good one will be to have two short pipes accurately inserted into the boiler; one into that part occupied by the water, and the other into that containing the steam; and the communication with both formed on the outside of the boiler, by means of a strong glass tube in this way the height of water may always be determined by sight. A stop-cock may be used, but will not, of course, be so convenient as the watergauge above. It would be well to have the steam-pipe going off from, or near, the most elevated part of the boiler: this will be a matter of convenience. For supplying the boiler with water, I will make use of any of the ordinary means. The pump for the supply of water may be so managed as to have, at will, a longer or shorter stroke, according to the demand of the boiler for water. In the construction of these improvements, I will employ any description of metal in common use for steam boilers, but I need not add that copper would be the best. The blast-box, where one is used, will, of course, vary in its structure, according to the most suitable adaptation to the boiler, as well as the bellows employed. The wind-pipe of the bellows may either be adapted to a blast-box, or may be moveable, so as to pass through a hole made in the door of the fire-place (where there is a door), or permanently fixed under the door, or at its side, or indeed in any

other convenient situation. As for the fastenings, or other modes of adapting the several parts of the boiler, &c., together, I need hardly mention that I will adopt any convenient modes now in common practice in similar cases.

After the exit of the flue from the boiler, it may, if thought proper, be carried through the water tank or vessel, destined to keep up the supply for the boiler, for the purpose of heating it before it is pumped into the boiler. No doubt most of the principles laid down in the preceding descriptions have, taken separately, been heretofore known; but I claim as my own the combinations of principles therein stated.

Description of the Drawings-Plate XVIII.

Fig. 2 is a vertical section showing the internal structure of the boiler, &c. The fuel fitted for a boiler made in this way

would be coal.

a, the fire-place.

b, the grate.

c, the blast-box, with a slide or door at the bottom.
d, the wind-pipe of the bellows.

e, the fuel-pipe.

f, a sliding door, shutting the fuel-pipe, and, when opened, permitting fuel to drop down from the fuel-receiver.

་

g, another sliding door, stopping the communication from the air when the slide ƒ is open.

open

h, the fuel-receiver or box.

i, i, i, space of the boiler occupied by the water.

k, space of the boiler filled with steam.

1, steam-pipe.

m, water-gauge.

n, n, n, flue-pipes: there may be four, more or less, passing down through the bottom of the boiler, and ending in a single larger flue-pipe.

Fig: 3 represents the bottom of the boiler pierced by the, flue-pipes n, n, &c.-b is the grate at the bottom of the fireplace.

n', is a larger flue, forming the exit from a flue or heat-box below the boiler; n, n, open into this flue-box, after having pierced through the bottom of the boiler.

Fig. 4 represents n, n, passing into flue-pipes, instead of passing from the boiler into a flue-box below. These flue-pipes, p, p, communicate with n'; they might, if convenient, be placed under the boiler..

Fig. 5 is a middle section of a boiler in the form of a parallelopiped, surmounted by a half cylinder. This is an excellent mode when the fuel is wood. When similar letters to those in fig. 1 are used, they represent portions of the boiler, &c., intended for similar purposes. The dotted additions to the figure VOL. IV. NO. 81. 1ST APRIL, 1830.

(b, c, d,) show how a grate, wind-box, and the wind-pipe of the bellows may be adopted.

o, is the door of the fire-place.-Ibid.

Specification of a Patent for a Machine for Ditching, or excavating Ground for Canals or other Purposes. Granted to GEORGE HENRICKS, Urbana, Champaign County, Ohio, August 5, 1829.

I MAKE a carriage or frame with four wheels, the front wheels being made and fixed in all respects like those of a common waggon. Under the body of the carriage, a plough, with the mouldboard, of any of the known forms, is fixed so as to extend along between the hind and fore wheels, the land-side of the plough standing in a line with the centre of the bed of the carriage or frame, so that the mould-board may reach nearly to one side; it is also to be depressed sufficiently below the wheels to turn up the required quantity of earth. In order to remove the earth as it is turned up by the plough, there are a number of elevators or boxes, made usually of strong sheet iron, somewhat in the manner of the elevators of a flour-mill, but much larger. These elevators are attached to each other, so as to form an endless band or chain, the boxes being connected to each other by means of strong links. These elevators are made to revolve by passing them round two revolving shafts or rollers, one of which is fixed as near to the mould-board of the plough as will allow the elevators to pass round: this stands longitudinally with the carriage and plough. The other roller is fixed by proper frame-work above, and extending to a distance beyond the side of the carriage. When this chain of elevators is made to revolve as the carriage is drawn forward by horses or oxen, the earth which is ploughed up is received into the elevators, is by them raised and carried beyond the side of the ditch, so as to be delivered or thrown upon the bank, or it may be thrown into carts, or on to stageing, in the digging of canals.

In order to cause the shafts to revolve, upon which the excavators are sustained, the lower of these shafts is geared to one of the hind wheels, from which teeth or cogs project inwards, so as to take into teeth or cogs, which form a trundle upon the end of the shaft, the planes of these wheels or trundles standing at right angles with each other. The shaft I generally make square, so that the flat sides of the elevators may exactly fit them on each face as they revolve. If made round, spikes must project from them in such a way as to check the elevators, and prevent their slipping round.

In order to insure the turning of that wheel of the carriage to which the shaft is geared, its periphery or rim has a number of projecting spikes of iron to lay hold of the ground, as, without these, it would slide instead of turning.