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BRAMAH

Volume 502 · 2,603 words · 1823 Edition

(Joseph), a practical Engineer and Machinist, was born at Stainborough in Yorkshire, on the 13th of April 1749. His father rented a farm on the estate of Lord Stratford, and, being the eldest of five children, he was intended for the same employment. He exhibited, at a very early age, an unusual talent for the mechanical arts, and succeeded, when he was quite a boy, in making two violonecellos, which were found to be very tolerable instruments, and in cutting a single block of wood into a violin, chiefly by means of tools which were forged for him by a neighbouring smith, whom, at a subsequent period of his life, he induced to assist him in London as one of his principal workmen. Notwithstanding the ingenuity which he had thus displayed, his destination in life might have precluded its further cultivation, had he not, fortunately for himself and for the public, been incapacitated, when he was about sixteen, by an accidental lameness in his ankle, for the pursuit of agricultural labour. He was then apprenticed to a Carpenter and Joiner, who seems, however, to have contributed but little to his improvement in mechanical knowledge.

When the term of his engagement was expired, he obtained employment for some time in the workshops of a Cabinetmaker in London, and soon after established himself as a principal in that business. Another accidental confinement left his mind at liberty for a time to occupy itself with reflection and invention; and he employed his involuntary leisure in the improvement of some of the most humble, but not the least useful, of domestic conveniences. He obtained a patent for his inventions, and established a manufacture of these and other similar articles in Denmark Street, Soho; where he continued to simplify and improve the arrangement of the pumps and pipes subservient to his principal purpose. He procured, in 1783, a patent for a water-cock, intended to allow the fluid a more uninterrupted passage through it, than was practicable in the ordinary construction. He afterwards removed to Piccadilly, and established the various branches of his manufactory in some extensive premises at Pimlico.

In 1784, Mr Bramah took out a patent for his improvement in locks, which certainly appear to be of very material importance: their peculiar character depends on the arrangement of a number of levers or sliders in such a manner, as to preserve, when at rest, a uniform situation, and to be only pressed down by the key to certain unequal depths, which nothing but the key can ascertain; the levers not having any stop to retain them in their required situation, except that which forms a part of the key. The construction is more particularly detailed in the specification of the patent (Repertory of Arts, V. 217.), as well as in the inventor's Dissertation on Locks, 8vo; and some additional modifications, allowing the key to be varied at pleasure, are described in a patent, dated in 1798. It is not easy to say why the application for an act of Parliament to prolong the privilege was unsuccessful, unless it was supposed that the inventor had been already sufficiently repaid for the share of ingenuity which his contrivance exhibited; but the report, that one of these locks had been readily opened, before a committee of the House of Commons, by means of a common quill, was a gross misrepresentation of the fact; the quill having in reality been previously cut into the required shape from the true key; and the experiment only served to show the perfection of the workmanship, so little force being required to overcome the resistance, when properly applied.

For different modifications of pumps and fire-engines, Mr Bramah took out three successive patents, the two last dated in 1790 and 1793. (Repertory, II. III.) His "rotative principle" consists in making the part, which acts immediately on the water, in the form of a slider, sweeping round a cylindrical cavity, and kept in its place by means of an eccentric groove; a construction which was very possibly suggested by his own inventive mind, but which had been before described, in a form nearly similar, by Ramelli, Cavalleri, Amontons, Prince Rupert, and Dr Hooke. The third patent related chiefly to the attachment of a considerable reservoir of water to the fire-engine, in a cylindrical form, and to the furnishing it with wheels of its own, of a proper size and strength to allow it to be conveniently worked.

There was somewhat more of originality in the idea of applying practically, to the purpose of a press, the well-known principle of the hydrostatic paradox; by which, as by a lever with arms capable of infinite variation, the smallest imaginable weight is made capable of holding in equilibrium a force incomparably greater. Mr Bramah's patent for the invention is dated in 1796 (Repertory, VI. 289.), and it has been one of the most successful of his numerous speculations. He added to it in a subsequent patent the contrivance of a "retainer," for keeping goods in a constant state of pressure, for an unlimited time after their removal from the press. The apparatus has certainly a considerable advantage in the great steadiness with which the force can 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 small and on a large scale; for copying writings, 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 employed in public-houses under the name of the Beer-machine: For this Mr Bramah took out a patent in 1797, describing it as part of an apparatus for retaining, drawing, and clarifying liquors (Repertory, IX. 361). He prefaces his specification with some general observations on the right of an inventor to a property both in the objects which he selects for his improvements, and in the means which he employs for the attainment of them; and demands of the public justice an ample security for both these rights; grounding this claim on his resolution to make a clear and unreserved disclosure of all his inventions. Besides the method of pumping up the liquors from the various casks through flexible pipes, without the necessity of entering the cellar, he 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 on its head, which is to be converted into a piston. He mentions also a filtering machine,—a vent peg,—a method of making pipes,—and a new form of stop-cocks.

In 1801 he obtained a patent for some improvements in the construction of steam-engines, particularly relating to the boilers; and in 1802, for a very elaborate and accurate machine for producing smooth and parallel surfaces on wood and other materials. The tools of different kinds employed in this machine, such as gouges, spokeshaves, and planes, are carried with a considerable velocity by a rotatory motion, and come successively in contact with the wood, which is placed on a moveable carriage gradually advancing: the centre or gudgeon of the axis or shaft, instead of a common step, is supported 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 also to be very easily and accurately regulated, 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 apprehended, that the constant friction of such a collar would cause it to require frequent repairs, in order 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 employed with perfect success. The specification includes the description of a mode of turning spherical surfaces, either convex or concave, by the simple contrivance of a tool moveable on an axis precisely perpendicular to that of the lathe; and 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 paper, with the assistance of new machinery, in large sheets, was secured to the inventor, by a patent, in 1805 (Repertory, 2 Ser. VIII. 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 retainers adapted to the hydrostatic press; but Mr Bramah had not leisure to introduce these arrangements into actual practice, although he had been at a considerable expense in preparing the apparatus.

His next invention was, however, very effectually carried into execution in a particular department, notwithstanding its unpromising appearance, as generally stated in the specification of the patent, which he obtained in 1806 (Repertory, 2 Ser. X. 329). He proposes to facilitate the process of printing, 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 engraved or projecting, and capable of being shifted at pleasure, so as to express any single line by a proper combination of the plates. This is described as 'a substitute for common printing, copperplate engraving, and calico printing; and the ink is intended 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 constructed the next year for the Bank of England, for numbering 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 each step, and that in a regular order. In fact, during the immense temporary circulation of one and two pound-notes, the Bank has been able, by this machinery, under the management of about 20 clerks, to perform the labour of 120, who were before required for the purpose.

Mr Bramah procured a patent, in 1809, for a mode of making and holding pens for writing, calculated to save the substance of the quill, by cutting a number of pens out of it, instead of a single one; and those, who are not in the habit of making their own pens, may often find a convenience in the portable form, in which this and other similar "pterophori" are arranged. In 1812, he brought forward his patent for the construction of main pipes, to be carried through the principal streets of a metropolis, of sufficient thickness to withstand a great force, to which the water within them is intended to be subjected, by proper pumps, furnished with air vessels; so that the water may not only be ready for the immediate extinction of fires, without the necessity of bringing an engine to the spot, but may also furnish a convenient moving power for various mechanical purposes, such as raising weights, by means of tubes sliding out of each other, like those of a telescope. He observes that he has frequently had occasion to employ a hydrostatic pressure, in many of his operations, equivalent to that of a column of water 20,000 feet high, which is about 4 tons for every square inch. He also asserts that he can form 500 tubes, each 5 feet long, capable of sliding within each other, and of being extended in a few seconds, by the pressure of air forced into them, to a length of 2500 feet; and, with a power of this kind, he seems to have imagined that he could raise wrecks, and regulate the descent of weights of various descriptions.

His improvements in wheel-carriages, for which he obtained a patent in 1814, consisted in fixing each wheel to a separate moveable axis, having its bearings at two distinct points of its length, but loosely inclosed between these points, in a cylinder filled with oil; and, in some cases, he proposes to fix the opposite wheels to the same axis, though with a power of turning very stiffly round it, in order to lessen the lateral motion of the shafts in very rough roads. He also suggests the use of pneumatic springs, formed by pistons, sliding in cylinders, as a substitute for common springs of metal.

The purpose of Mr Bramah's last patent was the prevention of the dry rot, by laying on the timber, meant to be preserved from it, a thin coat of Parker's Roman cement, much diluted with water; but he does not appear to have pursued this experiment, having transferred his right in the invention to other hands.

In addition to the seventeen patents which have been mentioned, he took out two or three others of less importance, at different times, besides a variety of contrivances, which he did not think necessary to appropriate to himself by a legal privilege. Mr Nicholson has mentioned a double plunger for a forcing pump, as described to him by Mr Bramah (Nich. Jour. VII. 50); which, in the form he has delineated, is certainly possessed of no particular advantage, producing only with a large apparatus the effect of a much smaller. Mr Bramah had erected, in the latter years of his life, some large machines at the Thames Bank, for sawing stones and timber; he had begun to devise some improvements in bridges and in locks for canals; and he had at one time been actually employed in the execution of some waterworks belonging to the department of the civil engineer, which he had completed with ability and with success. His great and various exertions appear in some measure to have exhausted the strength of his constitution; and his last illness was immediately occasioned by a severe cold, taken in the prosecution of his experiments on the tearing up of trees, made in Holt Forest. He died in his sixty-sixth year, on the 9th of December 1814.

Mr Bramah was a sincere believer in the doctrines of the Christian religion; and, notwithstanding his diversified avocations, he left several manuscript essays on religious subjects. In his moral character, he was cheerful, benevolent, and affectionate; in his habits he was neat and methodical; and he knew well how to temper liberality with economy. He often kept his workmen employed more for their sake than his own, when the stagnation of trade deprived him of the means of disposing of the products of their labour. It is surely on the characters of such individuals that the wealth and prosperity of the British empire most essentially depend; an inventive imagination, controlled by a sound judgment, an incessant activity of mind and body, a head that can direct, and a heart that can feel, are the genuine sources of that practical superiority which is well known to distinguish the productions of our national industry. (Life of Mr Bramah, by Dr Brown, in the New Monthly Magazine for April 1815.) (s. f.)