There was somewhat more of oriOndity in the ides Of applying to the PorPoue of pren, the wel -known principle of the hydrostatic paradox; by which, as by a lever with arms capable of infinite variation, the smallest imaginable weight is made es. pable of holding in equilibrium a force isoomparabll greater. Mr Brainah's patent for the invention s dated in I 796.,(Repertwy, VI. 889.),.and it has been one of theme* successful of his numerous spat's• dons. He added to it in a subsequent patent the contrivance of a 66 retainer," for beeping goods m a constant state of pressure, as emlimmed dine ail ter their removal from the press. The appentlo hat certainly a eomidevable advantage in the fret° steadiness with which the hem me be applied, in the facility with which it can be regulated, and the convenience with which it can be continued without alteration ; and it has been extensively applied both on a Innall and on a large scale; for copying writ ings, for pressing gunpowder, for proving cables and chains, for raising weights of various kinds, and for drawing piles, and pulling up trees by the roots.
A simple but a very convenient arrangement of little pumps and pipes has been very generally em ployed in public-houses under • the name of the Bt--machine : For this Mr Bramah took out a pa tent hi 1797, describing it as part of an apparatus for retaining, drawing, and clarifying liquors (Reper tory, 1X. 361). He prefaces his specification with some gezettal observations on the right of an inven tor to a property both in the objeeta which he se lects for his improvements, and in the means which he employs for the attakuneat of them ; and de mands of the public justice an ample security for both these rights ; grounding this claim on his rem, lutiqit to make a ()leer and unreserved disclosure of all his inventions. Besides the method of pumping up the liquors from the various casks through flexi ble pipes, without the necessity of catering the cel lar, be describes a mode of converting every cask into a forcing pump, excluding the air, and raising the liquor to any part of the house, by a load en its bead, which is to be converted into a piston.. He mentions also a filtering nsechine,--a vent pegi,—* method of making pipes,—and a new form of stop cocks.
In 1801 he obtained a patent for some improve ments in the construction of steam-engines, particu larly relating to the boilers ; and in 1802, for a very elaborate and accurate machine for producing smooth itnd parallel surfaces on wood and other materials. The tools of different kinds employed in this ma abiee, such as. gouges, spokeshaves, and planes, are carried with a coesiderable velocity by a rotatory motion, and come successively in contact with the weed, which is placed on a moveable carriage gra dually advancing ; the centre er of the axis or shaft, instead of a couunoi step, is seppert ed by a barrel of oil, to which it is fitted by a collar ; and this arrangement not only diminishes the friction very considerably, but allows the height of the shaft aloe tq be very easily and accurately re gulated, by means of a small forcing pump. The
inventor thinks this liquid support likely to be as permanent as it is advantageous ; but it may be ap prehended, that the constant friction of such a col lar would cause it to raqour,e frequent repaies, in or - der to. prevent the escape. of the oil so powerfully compressed. The machine has been erected on a large scale. in the Arsenal at Woolwich, and is em ployed With perfect success. The specification in cludes the description of a mode of turning, spheri cal surfaces, either convex or concave, by the simple contrivance of a tool moveable on an axis precisely perpendicular to that of the lathe ; awl of cutting out concentric shells, by fixing, in the same manner, a curved tool, nearly of the same form as that which is employed by the common turners for making wooden bowls.
An improvement in the processes for making pa. per with the asaisteeee of new machinery,. in large sheets, Was secured to the inventor, by a patent, in 1865 (Repertory, Sersir111. 1). The description is accompanied by that of a mode of drying the paper on sliding frames, hung on lines like sashes, and of keeping it in a state of compression by re tainers adapted to the hydrostatic press; but Mr Bramah had not leisure to introduce these arrange ments into actual practice, although he had been at a considerable expence in preparing the appara tus.
His next invention was, however, very effectually carried into execution in a particular department, notwithetanding its unpromising appearance, as ge nerally stated in the specification of the patent, which he obtained in 1806 (Repertory, 2 Ser. X. 829). He proposes to facilitate the process of print ing, by means of a roller, composed of a number of circular plates, closely fitted together, and turning on the same axis, each bearing twenty-six letters, with figures, spaces, and various marks, either en graved or projecting, and capable of being shifted at pleasure, so as to express any single line by a pro per combination of the plates. This is described as a substitute for common printing, copperplate en graving, tied calico printing; and the ink is ;Mend ed to be supplied by a trough fixed above and in contact with the cylinder. Now, it is obvious, that such a machine would be insufferably tedious and inconvenient for every purpose of common printing, which it would be scarcely possible to perform by its means; but when we discover that the inventor had probably in view the apparatus which he construct., ed the next year for the Bank of England, for num ber* and dating their notes, we shall be aware that the means were admirably adapted to the end ; a single line only being here wanted at once, in which a single figure was to be changed at eachstep, and that in a regular order. In fact, during the im mense temporary circulation of one and notes, the Bank has been able, by this machinery, under. the management of about 20 clerks, to per form the labour of 1W, who were before required for the purpose.