difference in the distance of the ends of the lever, k, from the pivot, 7, in the other. The smallest motion at u, figures 1, 3, and 7, or at a, a, fig. 8, becomes considerable at the other end of the correcting weight or lever. These results I consider to be the most important and valuable effects of my compensation weights.

My invention is to be used thus:-The balance of a chronometer is first to be adjusted for the mean temperatures, as already described, and the error equally divided at the extremes; then if, as the temperature changes towards 30° or 80° Fahrenheit, the divided error be fast of the rate at 55°, and the compensation weights, Y, are to be used, their laminæ are to be shortened by passing them through the holders; if slow of the rate, at 55° Fahrenheit, they are to be lengthened by drawing them out of the holders. After each adjustment of the compensation weights, Y, a diameter of each of the circular holes, s, in the correcting weights respectively must be made to coincide with the lines. drawn on each of the platforms, by moving the rings round upon them as already explained. But if the compensation weights, z, are to be used, the directions are as follows:-The balance is first to be adjusted for the mean temperatures as already described, and then the screws, k', k', in each of the compensation weights, z, turned inwards, so that the commencement of the said error and its correction may be simultaneous, this error being first equally divided at the extremes as directed above. Then, if the said error is not sufficiently corrected at the extremes, turn the adjusting arms in each compensation weight, z, from the centre of the balance until the correction of the said error is effected. Supposing the effect thereby produced to be more than required, turn them towards the centre of the balance. After each of these adjustments, a diameter of each of the circular holes, s, in each lever respectively must be made to coincide with the lines drawn on the corresponding correcting weight by turning one of the screws k, k', in each compensation weight, z, inwards or outwards as the readjustment may require. If the correcting weights be found too heavy or too light, take up their lamina through the holders, or draw them out therefrom, as the case may require by this alteration the effect of the correcting weights will be modified. The rubies at the extremities of the lamina

must be replaced after this correction in a position midway between the parts of each lever, k, marked, x, x, in fig. 8, by turning the lamina round upon their respective platforms until a diameter of the holes s, in each lever is replaced over a line on the correcting weight respectively. It is observable, that in effecting any of these adjustments or corrections in either of the compensation weights, y, or z, for the extreme temperatures, the position of the compensation weights themselves are not altered. When the correction of the said error in the extreme temperatures is not required to be very minute or exact, one of the compensation weights, z, will be sufficient, and the compensation weight on the other blade of the balance may be one of those now in use. On the other hand, if very great exactness be required, use one of the compensation weights, z, to about 30° or 90° Fahrenheit, and then resort to the other compensation weight, z, to complete the correction below or above those temperatures. To guard against accidents, a thin circular metal plate, of the same diameter as the compensation weight, y, or z, may be fixed over them by screws in their respective holders.

I do not claim as my invention any part whatever of the ordinary compensation balance, nor do I confine myself to the details shown and described as long as the peculiar character of my improvements be maintained; but I claim as my invention, and as my improvements in compensation balances of chronometers, the mode of constructing the compensation weights of chronometers, whereby they are so provided with laminæ that the expansion or contraction thereof shall, by acting on a part of the compensation weights, vary the effect of such weights on the compensation balance to which they are applied. In witness whereof, &c.

Enrolled May 25, 1844.

JOHN RICHARD LUND.

7

Specification of the Patent granted to FERDINAND CHARLES WARLICH, of Eccleston-street, Middlesex, Gentleman, for Improvements in the Manufacture of Fuel.-Sealed October 5, 1843.

WITH AN ENGRAVING.

To all to whom these presents shall come, &c., &c.— It is well known that fuel manufactured from small coal, together with tar, pitch, or other bituminous substance, will not resist the heat to which fuel is subjected on board steam-boats, particularly in hot climates; and the same has heretofore been liable to run or adhere together in a mass, and in some cases to disintegrate or crumble in the coal bunkers. Now, my invention has for its objects,

Firstly, the submitting fuel composed more or less of small coal and pitch, tar, or other bituminous matter, to high degrees of heat, in retorts.

Secondly, the construction of a peculiar retort and furnace for applying high degrees of heat to fuel made of coal and pitch, or other bituminous matter; and,

Thirdly, the introduction of air into retorts where fuel manufactured more or less of coal and pitch, or other bituminous matter, is being subjected to high degrees of heat; and also the application of exhausting apparatus to the retorts used in the manufacture of fuel made of coal and pitch, or other bituminous matter. And in order that my invention may be most fully understood and readily carried into effect, I will proceed to describe the means pursued by me. Fuel having before been made by combining small coal with pitch, tar, and other bituminous matters, and then compressing the same in moulds, it will not be necessary for me to enter into any particular description thereof, as my invention does not apply to the compounding of small coal and pitch, or other bituminous matter, nor to the pressing the same in moulds; my invention commencing after such combining and moulding have been accomplished. At the same time I would state, that I prefer the compound of coal and bituminous matter to be as follows, but I do not restrict my invention thereto :-I take from 5 to 15 per cent. of pitch and coal tar, and 95 to 85 per cent. of small coal, and subject them to heat, if necessary, in a suitable pan or boiler, and mix them intimately together;

and when pitch is used, it is melted before applying the coal and I have found it advantageous to use "heavy oil," to the extent of 2 to 5 per cent., and, excepting in very cold weather, heat is not required where only tar is used. And in cases where it is desirable to prevent the fuel evolving smoke when being burned, I combine from 2 to 5 per cent. of common salt, mixed in a dry state with the coal, or from 2 to 5 per cent. of alum, dissolved in about its own weight of hot water. The mixture is then, as heretofore, to be shaped and moulded into convenient sizes, and then to be subjected to heat according to my invention, which consists in placing such fuel into retorts, and heating the fuel therein from 400° and upwards of Fahrenheit, for six to eight hours or more, according to the sizes of the moulded fuel, and the compression it has been subjected to; by which I am enabled to drive off gases and matters which tend, if they remained in the fuel, to bring about the prejudicial effects to which fuel manufactured from similar materials, has heretofore been subject to; and the evaporation and evolving of such gases and matters is quickened and facilitated by the introduction of streams of air, and by exhausting or withdrawing the air and vapours from the retorts.

Description of the Drawings.

Fig. 1, shows an elevation of a retort and furnace, formed in brick or other fit material.

Fig. 2, is a plan thereof, showing the flues and other parts.

Fig. 3, is a transverse section of one of the retorts and furnaces.

Fig. 4, is a longitudinal section of the retort and furnace flues, and other parts of the apparatus. a, is the retort or chamber, in which the fuel to be manufactured is placed, and into which are conducted, by means of either pipes or flues, or both, streams of air highly heated by fire; and thus is a high degree of heat kept up to the manufacturing fuel within. The drawing clearly shows the nature of the retort, and means of applying heat. c, c, are rails for the carriages, fig. 5, to run on when in the retort, the carriages having several shelves, d, d, on which the manufactured fuel is placed. e, eduction ways for the gases or products driven off from the manufactured fuel; these ways, by a dip-pipe, f, convey the

products into the main, g, in the manner of distillation of coal for coal gas. The retorts are fitted with sliding doors, as shown, and the carriages with the fuel being run in, the doors are closed, and the fuel heated from 400° to 600 of Fahrenheit; and even higher temperature may be used when it is desired to make fuel for locomotive and other furnaces having a strong draft.

Fig. 6, shows a section; and,

Fig. 7, a plan of the exhausting apparatus I prefer to employ. It consists of two cylinders, h, h, open at bottom, working in two vessels, i, i, containing water; the vessels, h, h, being alternately raised and lowered by the beam, j, to which motion is communicated by means of the connecting-rod, k, by any suitable power. g, the main, having two branch pipes, 1, 7, with valves, m, m, opening upwards. n, n, are two dip-pipes into the tank of water, o, hence in working, the products will pass from the retorts into the main, g, thence into the vessels, h, and be driven thence below the water in the tank, o, the uncondensed products rising up through the water, and pass into the atmosphere. During the time that these processes are going on, streams of heated air pass into the retort through the openings, p, p, there being suitable apparatus for regulating the flow of such streams of air. By this means the atmosphere in the retorts will be constantly changed by exhaustion, whilst fresh dried and heated air flows into the retort; the degree of heat of the interior of the retort being ascertainable by the thermometer.

Having thus described the nature of my invention, and the best means I am acquainted with for performing the same, I would wish it to be understood, that I do not confine myself to the precise details, provided the peculiar character of any part of my invention be retained and I am aware that artificial heat has before been proposed to be used in drying fuel in ovens; but the heat in such cases has not been raised to a temperature sufficiently high to effect the object of my invention. And I would wish it to be understood, that in respect to the first part of my invention, I do not claim the application of heat generally to manufactured fuel composed of coal and bituminous matter, but only when heat of at least 400° of Fahrenheit is employed, and the fuel raised to a still