and coloured cotton-velvets, velveteens, velverets, thicksets, cords, and other cotton piece goods, commonly called fustians. Dated April 5, 1803.

RICHARD FRANCIS HAWKINS, of Woolwich, Kent, Gentleman; for a method of applying a certain power to the working of ships and other windlasses, ship and other winches, cranes, and other purposes, to which the same hath never before been employed. Dated April 5, 1803.

JOHN LEACH, of Merton Abbey, Surrey, Calico-printer; for improvements on steam-engine boilers; which improvements are applicable to boilers in general, Dated April 7, 1803.

DANIEL PAULIN DAVIS, of Bloomsbury-square, Middlesex; for a method of cleansing and sweeping chimnies. Dated April 11, 1803.

JOHN TODD, of Bolton, Lancashire, Cotton-spinner; for a method of weaving and manufacturing woollen, cotton, linen, silk, and worsted cloths or stuffs; and also certain improvements on, and additions to, the machines used in weaving, by means of looms wrought by water, steam-engines, or any other power.

Dated April 14, 1803.

WILLIAM HORROCKS, of Stockport, Cheshire, Cottonmanufacturer; for improvements on the loom for weaving of cotton, and other goods, by steam or water.

Dated April 20, 1803.

SAMUEL DAY, of Charter House Hinton, Somersetshire, Esquire; for an engine or time-piece, which he denominates, "The Watchman's Noctuary, and Labourer's Regulator." Dated April 20, 1803.

JAMES HALL, of Mellor, in the parish of Glossop, Derbyshire, Weaver; for improvements upon looms. Dated April 27, 1803.

Specification of the Patent granted to WILLIAM SPEER, of of the City of Dublin, Esquire; for an Improvement in the Construction of Hydrometers.

Dated August 2, 1802.

To all to whom these presents shall come, &c. Now KNOW YE, that in compliance with the said proviso, I the said William Speer do hereby describe and ascertain the nature of my said invention and improvement, and the manner in which the same is to be performed, that is to say: I construct my hydrometer, as usual, of a ball, or hollow metallic part, to which is affixed a short stem with a load or weight, and diametrically opposite a longer stem for the purpose of graduation. The figures and dimensions of those several parts may be varied according to the well-known principles of this instrument; but the peculiar advantages of my improvement consists in the figure and method of graduating the stem; by means of which the gradations of strength of spirits at any known temperature can be seen, at once, VOL. III.-SECOND SERIES.

M

by

by immersion of the instrument, without the necessity of changing weights, by trial, or making any computations, or refering to any tables or sliding-rule, or other instrument whatever. I accomplish these purposes by constructing the upper stem in the form of a polygonal prism, of such dimensions that the whole of the said stem shall float above the surface of the water, at the temperature of thirty-five degrees of the thermometer of Fahrenheit. And the surface of the water shall intersect the lowest line of graduation upon one of the faces of the prism. And upon the said face I mark lines of graduation at the several stations to which the instrument has been found to be immersed, and to float in known mixtures of water and ardent spirit, at different strengths, at the temperature of thirty-five degrees aforesaid, above or under proof, up to the strongest, which can be produced by distillation. And I mark the said graduations on the stem by numbers, denoting the ultimate results or strengths commonly known by the term per centages, which said results have heretofore been ascertained by computation instead of direct inspection, as is done by the instrument with my improvement. And farther, in explanation of the term per centage, I here observe, that a spirituous liquor is said to be ten per cent. or any other given quantity over hydrometer-proof, when it is so strong that one hundred gallons of the said spirit will admit of an addition of ten gallons of water to reduce it to the strength of proof, and it is said to be ten per cent. under proof when one hundred gallons of the spirit contains ten gallons more of water than the same quantity of proof-spirit contains. And, lastly, I engrave at the upper end of the said face, the figures 35, to denote that the graduations on that face of the prism are applicable to spirits at that temperature, or number of degrees.

And

And moreover, upon the next contiguous face of the prism, I form and apply, by the means aforesaid, a similar graduation for an higher temperature, such for example as the temperature of forty degrees. And again, upon the face or side next contiguous to the lastmentioned face or side, I form and apply a similar graduation for a still higher temperature, such for example as the temperature of fifty degrees; and in this manner I graduate the several faces of my stem, so that the face last graduated shall be applicable to the highest ordinary temperature, as for example seventy degrees. The number of sides of the polygon may be greater or less, according to the number of temperatures respectively, to which the determinations are required to be made; but I adopt and recommend eight sides as the best adapted for the general purposes of revenue and commerce, so that each side shall bear a scale of per centages of spirit, differing in temperature, by two degrees, namely, beginning at 35 degrees and ending at 70 degrees. And to prevent any error which might possibly arise from an unskilful operator reading off the strength upon a wrong face of the instrument, I apply to the stem a small index, which embraces the same, and can be slided upwards and downwards to any part thereof, so as to point at the proper division. This index, which is of a different colour from the stem itself, constitutes part of the weight of the instrument above the fluid, but it is by no means a trial weight, for it is put on from the indication of temperature before the instrument is immersed at all. And farther, although it is very easy, from the contiguity of the divided faces, for each temperature upon the eightsided instrument to read the result for the intermediate temperatures to a degree of precision fully adequate to the purposes of revenue and trade; I do nevertheless

make and apply, as an addition to the said improved instrument, (to be used or not, at the pleasure of the operator,) two other indexes, which, being lighter than the first-mentioned index, do cause the instrument to shew the strengths at two equal intermediate temperatures between those marked upon any contiguous face of the general scale. Thus, for example, supposing the temperature fifty degrees, nothing farther would be required but to place the index No. 1 on the side marked fifty, and immerse it in the fluid, of which it will at once shew the strength; but if the temperature be 51 or 52, I usẹ the next lighter index, marked No. 2, which will cause the graduations to indicate strengths for the temperaturę 511; or in case the temperature had been 53 or 54, then the index No. 3 would have been to be applied, and the said face would then indicate strengths for the tempera, ture 53, so that the result by the instrument will be true for the intermediate temperatures within half a degree; and even this small difference, if attended to, or thought of any importance, may be obtained by holding the jar containing the spirit a few moments in the hand.

And in the construction of an instrument for the immediate purposes of revenue and trade, I do recommend, and in practice, make the graduations on the stem to comprehend only those per centages, or strength, which are met with in the spirits usually dealt in in commerce, instead of beginning my graduations as low as water, near which strength no spirits are made or sold; or of carrying the said graduations up to the very highest alcohol, which is, comparatively, an article of little sale or transfer. By which means, I render my instrument more convenient, and the divisions more open and close. And with regard to the higher or lower strengths I would recommend another stem to be applied to the same

instrument,