Industrial Biography: Iron Workers and Tool Makers

by Samuel Smiles

We next find Bramah turning his attention to the invention of a lock that should surpass all others then known. The locks then in use were of a very imperfect character, easily picked by dexterous thieves, against whom they afforded little protection. Yet locks are a very ancient invention, though, as in many other cases, the art of making them seems in a great measure to have become lost, and accordingly had to be found out anew. Thus the tumbler lock—which consists in the use of moveable impediments acted on by the proper key only, as contradistinguished from the ordinary ward locks, where the impediments are fixed—appears to have been well known to the ancient Egyptians, the representation of such a lock being found sculptured among the bas-reliefs which decorate the great temple at Karnak. This kind of lock was revived, or at least greatly improved, by a Mr. Barron in 1774, and it was shortly after this time that Bramah directed his attention to the subject. After much study and many experiments, he contrived a lock more simple, more serviceable, as well as more secure, than Barron's, as is proved by the fact that it has stood the test of nearly eighty years' experience,[1] and still holds its ground. For a long time, indeed, Bramah's lock was regarded as absolutely inviolable, and it remained unpicked for sixty-seven years until Hobbs the American mastered it in 1851. A notice had long been exhibited in Bramah's shop-window in Piccadilly, offering 200L. to any one who should succeed in picking the patent lock. Many tried, and all failed, until Hobbs succeeded, after sixteen days' manipulation of it with various elaborate instruments. But the difficulty with which the lock was picked showed that, for all ordinary purposes, it might be pronounced impregnable.

The new locks were machines of the most delicate kind, the action of which depended in a great measure upon the precision with which the springs, sliders, levers, barrels, and other parts were finished. The merits of the invention being generally admitted, there was a considerable demand for the locks, and the necessity thus arose for inventing a series of original machine-tools to enable them to be manufactured in sufficient quantities to meet the demand. It is probable, indeed, that, but for the contrivance of such tools, the lock could never have come in to general use, as the skill of hand-workmen, no matter how experienced, could not have been relied upon for turning out the article with that degree of accuracy and finish in all the parts which was indispensable for its proper action. In conducting the manufacture throughout, Bramah was greatly assisted by Henry Maudslay, his foreman, to whom he was in no small degree indebted for the contrivance of those tool-machines which enabled him to carry on the business of lock-making with advantage and profit.

Bramah's indefatigable spirit of invention was only stimulated to fresh efforts by the success of his lock; and in the course of a few years we find him entering upon a more important and original line of action than he had yet ventured on. His patent of 1785 shows the direction of his studies. Watt had invented his steam-engine, which was coming into general use; and the creation of motive-power in various other forms became a favourite subject of inquiry with inventors. Bramah's first invention with this object was his Hydrostatic Machine, founded on the doctrine of the equilibrium of pressure in fluids, as exhibited in the well known 'hydrostatic paradox.' In his patent of 1785, in which he no longer describes himself as Cabinet maker, but 'Engine maker' of Piccadilly, he indicated many inventions, though none of them came into practical use,—such as a Hydrostatical Machine and Boiler, and the application of the power produced by them to the drawing of carriages, and the propelling of ships by a paddle-wheel fixed in the stern of the vessel, of which drawings are annexed to the specification; but it was not until 1795 that he patented his Hydrostatic or Hydraulic Press.

Though the principle on which the Hydraulic Press is founded had long been known, and formed the subject of much curious speculation, it remained unproductive of results until a comparatively recent period, when the idea occurred of applying it to mechanical purposes. A machine of the kind was indeed proposed by Pascal, the eminent philosopher, in 1664, but more than a century elapsed before the difficulties in the way of its construction were satisfactorily overcome. Bramah's machine consists of a large and massive cylinder, in which there works an accurately-fitted solid piston or plunger. A forcing-pump of very small bore communicates with the bottom of the cylinder, and by the action of the pump-handle or lever, exceeding small quantities of water are forced in succession beneath the piston in the large cylinder, thus gradually raising it up, and compressing bodies whose bulk or volume it is intended to reduce. Hence it is most commonly used as a packing-press, being superior to every other contrivance of the kind that has yet been invented; and though exercising a prodigious force, it is so easily managed that a boy can work it. The machine has been employed on many extraordinary occasions in preference to other methods of applying power. Thus Robert Stephenson used it to hoist the gigantic tubes of the Britannia Bridge into their bed,[2] and Brunel to launch the Great Eastern steamship from her cradles. It has also been used to cut bars of iron, to draw the piles driven in forming coffer dams, and to wrench up trees by the roots, all of which feats it accomplishes with comparative ease.

The principal difficulty experienced in constructing the hydraulic press before the time of Bramah arose from the tremendous pressure exercised by the pump, which forced the water through between the solid piston and the side of the cylinder in which it worked in such quantities as to render the press useless for practical purposes. Bramah himself was at first completely baffled by this difficulty. It will be observed that the problem was to secure a joint sufficiently free to let the piston slide up through it, and at the same time so water-tight as to withstand the internal force of the pump. These two conditions seemed so conflicting that Bramah was almost at his wit's end, and for a time despaired of being able to bring the machine to a state of practical efficiency. None but those who have occupied themselves in the laborious and often profitless task of helping the world to new and useful machines can have any idea of the tantalizing anxiety which arises from the apparently petty stumbling-blocks which for awhile impede the realization of a great idea in mechanical invention. Such was the case with the water-tight arrangement in the hydraulic press. In his early experiments, Bramah tried the expedient of the ordinary stuffing-box for the purpose of securing the required water tightness' That is, a coil of hemp on leather washers was placed in a recess, so as to fit tightly round the moving ram or piston, and it was further held in its place by means of a compressing collar forced hard down by strong screws. The defect of this arrangement was, that, even supposing the packing could be made sufficiently tight to resist the passage of the water urged by the tremendous pressure from beneath, such was the grip which the compressed material took of the ram of the press, that it could not be got to return down after the water pressure had been removed.

In this dilemma, Bramah's ever-ready workman, Henry Maudslay, came to his rescue. The happy idea occurred to him of employing the pressure of the water itself to give the requisite water-tightness to the collar. It was a flash of common-sense genius—beautiful through its very simplicity. The result was Maudslay's self-tightening collar, the action of which a few words of description will render easily intelligible. A collar of sound leather, the convex side upwards and the concave downwards, was fitted into the recess turned out in the neck of the press-cylinder, at the place formerly used as a stuffing-box. Immediately on the high pressure water being turned on, it forced its way into the leathern concavity and 'flapped out' the bent edges of the collar; and, in so doing, caused the leather to apply itself to the surface of the rising ram with a degree of closeness and tightness so as to seal up the joint the closer exactly in proportion to the pressure of the water in its tendency to escape. On the other hand, the moment the pressure was let off and the ram desired to return, the collar collapsed and the ram slid gently down, perfectly free and yet perfectly water-tight. Thus, the former tendency of the water to escape by the side of the piston was by this most simple and elegant self-adjusting contrivance made instrumental to the perfectly efficient action of the machine; and from the moment of its invention the hydraulic press took its place as one of the grandest agents for exercising power in a concentrated and tranquil form.

Bramah continued his useful labours as an inventor for many years. His study of the principles of hydraulics, in the course of his invention of the press, enabled him to introduce many valuable improvements in pumping-machinery. By varying the form of the piston and cylinder he was enabled to obtain a rotary motion,[3] which he advantageously applied to many purposes. Thus he adopted it in the well known fire-engine, the use of which has almost become universal. Another popular machine of his is the beer-pump, patented in 1797, by which the publican is enabled to raise from the casks in the cellar beneath, the various liquors sold by him over the counter. He also took out several patents for the improvement of the steam-engine, in which, however, Watt left little room for other inventors; and hence Bramah seems to have entertained a grudge against Watt, which broke out fiercely in the evidence given by him in the case of Boulton and Watt versus Hornblower and Maberly, tried in December 1796. On that occasion his temper seems to have got the better of his judgment, and he was cut short by the judge in the attempt which he then made to submit the contents of the pamphlet subsequently published by him in the form of a letter to the judge before whom the case was tried.[4] In that pamphlet he argued that Watt's specification had no definite meaning; that it was inconsistent and absurd, and could not possibly be understood; that the proposal to work steam-engines on the principle of condensation was entirely fallacious; that Watt's method of packing the piston was "monstrous stupidity;" that the engines of Newcomen (since entirely superseded) were infinitely superior, in all respects, to those of Watt;—conclusions which, we need scarcely say, have been refuted by the experience of nearly a century.

On the expiry of Boulton and Watt's patent, Bramah introduced several valuable improvements in the details of the condensing engine, which had by that time become an established power,—the most important of which was his "four-way cock," which he so arranged as to revolve continuously instead of alternately, thus insuring greater precision with considerably less wear of parts. In the same patent by which he secured this invention in 1801, he also proposed sundry improvements in the boilers, as well as modifications in various parts of the engine, with the object of effecting greater simplicity and directness of action.

In his patent of 1802, we find Bramah making another great stride in mechanical invention, in his tools "for producing straight, smooth, and parallel surfaces on wood and other materials requiring truth, in a manner much more expeditious and perfect than can be performed by the use of axes, saws, planes, and other cutting instruments used by hand in the ordinary way." The specification describes the object of the invention to be the saving of manual labour, the reduction in the cost of production, and the superior character of the work executed. The tools were fixed on frames driven by machinery, some moving in a rotary direction round an upright shaft, some with the shaft horizontal like an ordinary wood-turning lathe, while in others the tools were fixed on frames sliding in stationary grooves. A wood-planing machine[5] was constructed on the principle of this invention at Woolwich Arsenal, where it still continues in efficient use. The axis of the principal shaft was supported on a piston in a vessel of oil, which considerably diminished the friction, and it was so contrived as to be accurately regulated by means of a small forcing-pump. Although the machinery described in the patent was first applied to working on wood, it was equally applicable to working on metals; and in his own shops at Pimlico Bramah employed a machine with revolving cutters to plane metallic surfaces for his patent locks and other articles. He also introduced a method of turning spherical surfaces, either convex or concave, by a tool moveable on an axis perpendicular to that of the lathe; and of cutting out concentric shells by fixing in a similar manner a curved tool of nearly the same form as that employed by common turners for making bowls. "In fact," says Mr. Mallet, "Bramah not only anticipated, but carried out upon a tolerably large scale in his own works—for the construction of the patent hydraulic press, the water-closet, and his locks—a surprisingly large proportion of our modern tools." [6] His remarkable predilection in favour of the use of hydraulic arrangements is displayed in his specification of the surface-planing machinery, which includes a method of running pivots entirely on a fluid, and raising and depressing them at pleasure by means of a small forcing-pump and stop-cock,—though we are not aware that any practical use has ever been made of this part of the invention.

Bramah's inventive genius displayed itself alike in small things as in great—in a tap wherewith to draw a glass of beer, and in a hydraulic machine capable of tearing up a tree by the roots. His powers of contrivance seemed inexhaustible, and were exercised on the most various subjects. When any difficulty occurred which mechanical ingenuity was calculated to remove, recourse was usually had to Bramah, and he was rarely found at a loss for a contrivance to overcome it. Thus, when applied to by the Bank of England in 1806, to construct a machine for more accurately and expeditiously printing the numbers and date lines on Bank notes, he at once proceeded to invent the requisite model, which he completed in the course of a month. He subsequently brought it to great perfection the figures in numerical succession being changed by the action of the machine itself,—and it still continues in regular use. Its employment in the Bank of England alone saved the labour of a hundred clerks; but its chief value consisted in its greater accuracy, the perfect legibility of the figures printed by it, and the greatly improved check which it afforded.