in which also moves a piston, having the upper end of its rod pressing against a moveable plank E, between which and the large beam above is placed the substance to be subjected to pressure, as, for example, a pile of new-bound books. By the ac. tion of the pump handle, water is raised into the small cylinder, and on depressing the piston, it is forced through a valve at B into the large cylinder, and raises the piston D, which expends its whole force on the bodies confined at E. Now, since whatever force is applied to any one portion of the fluid extends alike to every part, therefore the force which is exerted by the pump upon the smaller column, is transmitted unimpaired to every inch of the larger column, and tends to raise the moveable plank, E, with a force as much greater, in the aggregate, than that impressed upon the surface of the smaller, as this surface is smaller than that of the larger column; or (which is the same thing) as the number of square inches in the end of the piston B is less than that of the piston D. The power of such a machine is enormously great; for supposing the hand to be applied at the end of the handle with a force of only ten pounds, and that this handle or lever is so constructed as to multiply that force but five times, the force with which the smaller piston will descend will be equal to fifty pounds; and let us suppose that the head of the larger piston contains the smaller fifty times, then the force exerted to raise the press board will equal two thousand five hundred pounds. A man can indeed easily exert ten times the force supposed, and can therefore exert a force upon the substance under pressure equal to twenty-five thousand pounds!

Here, too, the mere application of the puny force of a child's arm is sufficient to tear up trees by the roots, and crush bars of iron as though they were pieces of wax. If as an invention for developing power it is equal in importance to the steam engine, but unlike it, its use is not limited by any circumstances of a local nature, for it does not depend on a consumption of any extraneous substance whatever; two small pipes, each fitted with a piston and a little water, which for years needs no replenishing, gives to an ordinary man in all situations the strength of a giant.

This machine, one of the most admirable in the whole compass of the arts, has been called, by some envious blockheads, "Pascal's Machine;" and, in their descriptions, they almost say Pascal invented it; but that ingenious philosopher has about as much claim to this great honor, as the old woman who first discovered her beard and her wrinkles in her polished pewter platter, had to be considered as the inventress of the Newtonian telescope! Before Bramah's time, Bonifaces were obliged to trudge to the

cellar for every drop of the beverage they measured out to their customers, or have their barrels placed in waiting on the same level with their parlor. In most states of the weather this was a hazardous position, and in some atmospheres very injurious; but Bramah, by his elegant "Beer Machine," enabled them to pump up into the measure, in the bar, the fermented juice contained in the various casks in the cellar.

Machinery for smoothing surfaces was another of his elaborate and beautiful specimens of mechanism. It was erected at the Woolwich Arsenal with perfect success: the axis of the principal shaft was supported on a piston in a vessel of oil, which diminished the friction considerably, and could be accurately measured by means of a small forcing pump. He introduced also a mode of turning spherical surfaces either convex or concave, by a tool moveable on an axis perpendicular to that of the lathe; and fixing a curved tool in the same position, he cut out concentric sheets. He also described machinery for making paper in large sheets, for printing by means of a roller, composed of a number of circular plates, turning on the same axis, each bearing twenty-six letters capable of being shifted at pleasure, so as to express any single line by a proper combination of the plates. This was put in practice to number bank notes, and enable the clerks to do six where before they could only number one.

In 1812, he produced his project for main pipes, which in some parts was more ingenious than practicable. In describing them, he mentions having employed an hydrostatic pressure equal to that of a column of water twenty thousand feet high, (about four tons for every inch.) He also asserts that he can form five hundred tubes, each five 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 two thousand five hundred feet; with this power he proposed to raise wrecks, and regulate the descent of weights. His improvements in wheel carriages consisted in fixing each wheel to a separate moveable axis, having its bearings at two distinct points of its length, but loosely enclosed between those points in a cylinder filled with oil; in another, opposite wheels were to be fixed on the same axis, though with the power of turning very stiffly round it to lessen the lateral motion on rough roads; and he suggests pneumatic springs, formed by pistons sliding in cylinders, as a substitute for springs of metal: latterly he improved the machines for sawing stones and timber, and suggested some alterations in the construction of bridges and canal locks. His last illness was occasioned by a severe cold,

taken during some experiments in tearing up of trees in a forest He died on the 9th of December, 1814.

Bramah was a sincere and unostentatious follower of the precepts of Christianity: his conversation was animated, and to much facility of expression he added the most perfect independence of opinion he was a cheerful, benevolent, and affectionate manneat and methodical in his habits-and knew well how to temper liberality with economy. Greatly to his honor, he often kept his workmen employed, solely for their sake, when the stagnation of trade prevented him disposing of the products of their labor. As a manufacturer, he was distinguished for his promptitude and integrity, and celebrated for the exquisite finish which he gave to his productions

ANECDOTES, DESCRIPTIONS,

ETC., ETC,

RELATING TO THE MECHANIC ARTS.

Progress of Invention illustrated.

THE progressive stages through which even some of our simplest tools have to pass, ere they arrive at their final state of perfection, is sometimes astonishing. The simple process of drawing a cork will furnish the necessary illustrations.

The inventor of bottles is unknown; but these were in use centuries before corks were thought of, and these, again, were employed for generations before a convenient method was hit upon for their extraction. The exhilarating contents could then only be tasted by what was technically called "beheading the bottle." More expert practitioners had many opportunities of showing their skill in removing the impediment by a dexterous twist of the fingers; or, if that were impracticable, teeth were called in as their natural auxiliaries: here, however, in many cases, it was doubtful whether the cork would follow the teeth, or the teeth remain in the cork; and if an obstinate remnant would remain, a nail was a ready means of dislodging the stubborn plug, particle by par ticle. When at any time, through an impatience of the nibbling labor, or a despair of accomplishing a clean extraction at all, it was resolved to send the obstacle the wrong way; this was then, indeed, an invaluable instrument. A pair

of skewers, or forks, inserted "witchwise," would sometimes accomplish those difficult cases which had baffled the exertions of all the natur als. Twisting the lower extremity of the "bare bodkin" into a spiral form, and adding a handle to it, was the thought of a master genius; and in this shape mankind for ages were contented to avail themselves of its services; and even at the present hour, some barbarous, uncouth countries and districts may be named where it is still the extractor in most general use. In our coun. try, it must be in the recollection of many, that this was in numerous cases a very inefficient machine; and no one hostess ever before conferred such a favor upon all bottle suckers as that lady who first conceived the idea of placing a button at the end of the screw.worm. Henceforth the decanting process was a mere matter of routine. When, in her green old age, death laid his hand on the inventress, a piratical screw. maker also took to himself the credit and profit of the button. Yet the fair originator shall be ne'er forgotten, even although her master-piece,

some years later, was eclipsed, and may yet be superseded by the King's screw, which can receive no addition to its beauty or convenience.

Another illustration can be found in the shoemaker's awl, which is a much simpler instrument, even than the cork-screw. The first awls were plain, conical punches, that made a round hole in the leather. It was soon discovered that this form was erroneous, for the hole thus made was never more than half filled with the two waxed threads crossing each other. Geometry teaches us that these two threads, being like two small circles enclosed by a third, occupied but one half of the space of the hole.

The conical awl was then flattened, and had an oval form as to its section given to it; and some time afterwards the awl was so filed as to give it four faces, the section being something in the shape of a lozenge; but still the awl was straight. Although this straightness is useful in many cases, yet it was improper in the business of shoemaking. Suppose it were wished to sew together,