appreciated, the interests of the manufacturers and weavers brought it into general use, in spite of all opposition. A desperate effort, though, was made in 1779-probably in a period of temporary distress-to put down the machine. A mob rose and scoured the country for several miles around Blackburn, demolishing the jennies, and with them all the carding engines, water frames, and every machine turned by water or horses. It is said the rioters spared the jennies which had only twenty spindles, as these were by this time admitted to be useful, but those with a greater number, being considered mischievous, were destroyed, or cut down to the prescribed dimensions.

It may seem strange that not merely the working classes, but even the middle and higher ranks of people, entertained a great dread of machinery. Not perceiving the tendency of any inven. tion which improved and cheapened the manufacture, to cause an extended demand for its products, and thereby to give employment to more hands than it superseded, those classes were alarmed lest the poor rates should be burdened with workmen thrown idle. They therefore connived at, and even actually joined in the opposition to the machinery, and did all in their power to screen the rioters from punishment.

This devastating outrage left effects more permanent than have usually resulted from such commotions. Spinners and other capitalists were driven from the neighborhood of Blackburn to Manchester and other places, and in consequence it was many years before cotton spinning was resumed at Blackburn.

Hargreaves went to Nottingham in 1768, and worked for a while in the employment of Mr. Shipley, for whom he secretly made some jennies in his dwelling. He was induced, by the offers of Mr. Thomas James, to enter into partnership with him; and the latter raised sufficient money, on mortgage and loan, to build a small mill in Hockley, where they spun yarn for the hosiers with the jenny. The patent was obtained in 1770.

Finding that several of the Lancashire manufacturers were using the jenny, Hargreaves gave notice of actions against them: the manufacturers met, and sent a delegate to Nottingham, who offered Hargreaves three thousand pounds for permission to use the machine; but he at first demanded seven thousand, and at last stood out for four thousand. The negotiation being broken off, the actions proceeded; but before they came to trial, Hargreaves' attorney was informed that his client, before leaving Lancashire, had sold some jennies to obtain clothing for his children, of whom he had six or seven. In consequence, the attorney gave up the actions, in despair of obtaining a verdict.

The spinning business was carried on by the partners with mo. derate success, till the death of Mr. Hargreaves, which took place at his own house, near the mill, in April, 1778. In his will he directed a guinea to be given to the vicar for preaching his funeral sermon. His widow received four hundred pounds from Mr. James, for her husband's share in the business.

It is a consolation to the admirers of genius to know, that this benefactor to his country was enabled to live in comfort, though not in affluence, on the fruits of his invention.

JOSEPH BRAMAH,

THE INVENTOR OF THE HYDROSTATIC PRESS.

JOSEPH BRAMAH, one of the greatest mechanics England has ever produced, was the oldest son of a small farmer, and was born on the 13th of April, 1749, at Stainsborough, in Yorkshire. He exhibited at a very early age an unusual talent for mechanical contrivances, and succeeded, when quite a boy, in making two violoncellos, which were found to be very tolerable instruments. His hours of relaxation from the business of the farm were generally spent in a neighboring blacksmith-shop, between whose tenant and himself was shared the merit of several ingenious pieces of mechanism.

An accidental lameness in his ankles unfitting him for agricul tural labor, he was apprenticed in his sixteenth year to a carpenter and joiner. At the expiration of his "time," he went to London in search of employment, where, by his industry and exertions, he soon became a master. His now extended means enabled him to indulge his mechanical taste, and he quickly became known as a man possessing a fine invention as well as great executive skill. In 1784, he produced the admirable lock which bears his name, and which was considered the most perfect mechanism of its kind that had ever been produced, and even to this day is scarcely rivalled for safety, durability, elegance, and simplicity. The peculiar character of this lock depends on the arrangement of a number of levers, or sliders, to preserve, when at rest, a uniform situation, and to be only pressed down by the key to a certain depth, which nothing but the key can ascertain, the levers not having any stop to retain them in their required situation, except

that which forms part of the key. He added afterwards some modifications, for allowing the key to be varied at pleasure. 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. An experiment which was only made to show the perfection of the workmanship, and the very small force requisite to overcome the resistance when properly applied. It has been stated that one of these locks, after having been in use many years, and opened and locked not less than four hundred thousand times, was apparently as perfect as when first constructed. The invention for which he will probably be best known to posterity, is his hydrostatic press, which is described in the succeeding paragraph :

The principle of this machine is this: if a given pressure, as that given by a plug forced inwards upon a square inch of the surface of a fluid confined in a vessel, is suddenly communicated to every square inch of the vessel's surface, however large, and to every inch of the surface of any body immersed in it, thus if we attempt to force a cork into a vessel full of water,—the pressure will not merely be felt by the portion of the water directly in the range of the cork, but by all parts of the mass alike; and the liability of the bottle to break, supposing it to be of uniform strength throughout, will be as great in one place as another. And a bottle will break at the point wherever it is the weakest, however that point may be situated relatively to the place where the cork is applied; and the effect will be the same whether the stopper be inserted at the top, bottom, or side of the vessel. It is this power which operates with such astonishing effect in the Hydrostatic Press. The annexed engraving represents a press made of the strongest timbers, the foundation of which is com

monly laid in solid masonry. A B is a small cylinder, in which moves the piston of a forcing pump, and C D is a large cylinder,

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 action 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,