the idea of her smelting processes and iron-castings from Germany and Holland; but the discovery of that important material, cast-steel, belongs, at least, to one of her own sons. Yet even here the relationship is a merely conventional one, for Benjamin Huntsman (1704-1776) was the child of German parents who had settled in Lincolnshire.Huntsman's original calling was that of a clock-maker; but his remarkable mechanical skill, his shrewdness, and[Pg 15] his practical sense, soon gave him the repute of the 'wise man' of the district, and brought neighbours to consult him not only as to the repair of every ordinary sort of machinery, but also of the human frame--the most complex of all machines! It was his daily experience of
the inferior quality of the tools at his command that led him to make experiments in the manufacture of steel. What his experiments were we have no record to show; but that they must have been conducted with Teutonic patience and thoroughness there can be no doubt, from the formidable nature of the difficulties overcome.
England, however, long refused to make use of Huntsman's precious material, although produced in her very midst. The Sheffield cutlers would have nothing to do with a substance so much harder than anything they were accustomed to, and Huntsman was actually compelled to look for his market abroad! All the cast-steel he could manufacture was sent over to France, and the merit of employing this material for general purposes belongs originally to that country. The inventions of Henry Cort (1740-1800) for refining and rolling iron (1785) were the mainspring of the malleable iron trade, and made Great Britain independent of Russia and Sweden for supplies of manufactured iron. One authority has stated that since 1790, when Cort's improvements were entirely established, the value of landed property in England had doubled. But he was unfortunate in business life, and in 1811 upwards of forty iron firms subscribed towards a fund for the assistance of his widow and nine orphan children. David Mushet (1772-1847) did much for the ex-
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pansion of the iron trade in Scotland by his preparation of steel from bar-iron by a direct process, combining the iron with carbon, and by his discovery of the effect of manganese on steel.
Steel is the material of which the instruments of labour[Pg 16] are essentially made. Upon the quality of the material, that of the instrument naturally depends, and upon the quality of the instrument, that, in great measure, of the work. Watt's marvellous invention ran great risk, at one time, of being abandoned, for the simple reason that the mechanical capacities of the age were not 'up' to its embodiment. Even after Watt had secured the aid of Boulton's best workmen, Smeaton gave it as his opinion that the steam-engine could never be brought into general use, because of the difficulty of getting its various parts made with the requisite precision.
The execution by machinery of work ordinarily executed by hand-tools has been a gigantic stride in the path of material civilisation. The earliest phase of the great modern movement in this direction is represented, probably, by the sawmill. A sawmill was erected near London as long ago as 1663--by a foreigner--but was shortly abandoned in consequence of the determined hostility of the sawyers; and more than a century elapsed before another mill was put up. But the sawmill is comparatively a rude structure, and
the material it operates upon is easily treated, even by the hand. When we come to deal, however, with such substances as iron and steel, the benefit of machinery becomes incalculable. Without our recent machine-tools, indeed, the stupendous iron creations of the present day would have been impossible at any cost; for no amount of hand-labour could ever attain that perfect exactitude of construction without which it would be idle to attempt fitting the component parts of these colossal structures together.
The first impulse, however, to the improvement of machine-tools for ironwork was given by a difficulty born not of mass but of minuteness.
Up to the end of the last century, the locks in common[Pg 17] use among us were of the rudest description, and afforded scarcely any security against thieves. To meet this universal want, Joseph Bramah set his remarkable inventive faculties to work, and speedily contrived a lock so perfect, that it held its ground for many a day. But Bramah's locks are machines of the most delicate kind, depending for their efficiency upon the precision with which their component parts are finished; and, at that time, the attainment of this precision, at such a price as to render the lock an article of extensive commerce, seemed an insuperable difficulty. In his
dilemma, Bramah's attention was directed to a youngster in the Woolwich Arsenal smithy, named Henry Maudsley, whose reputation for ingenuity was already great among his fellows. Bramah was at first almost ashamed to take such a mere lad into his counsels; but a preliminary conversation convinced him that his confidence would not be misplaced. He persuaded Maudsley to enter his employment, and the result was the invention, between them, of the planing-machine, applicable either to wood or metal, as also of certain improvements in the old lathe, more particularly of that known as the 'slide-rest.'
In the old-fashioned lathe, the workman guided his cutting-tool by sheer muscular strength, and the slightest variation in the pressure necessarily led to an irregularity of surface. The rest for the hand is in this case fixed, and the tool held by the workman travels along it. Now, the principle of the slide-rest is the opposite of this. The rest itself holds the tool firmly fixed in it, and slides along the bench in a direction parallel with the axis of the work. All that the workman has to do, therefore, is to turn a screw-handle, by means of which the cutter is carried along with the smallest possible expenditure of strength; and even this trifling labour has been since
got rid of, by making the rest self-acting.[Pg 18]
Simple and obvious as this improvement seems, its importance cannot be overrated. The accuracy it insured was precisely the desideratum of the day! By means of the slide-rest, the most delicate as well as the most ponderous pieces of machinery can be turned with mathematical precision; and from this invention must date that extraordinary development of mechanical power and production which is a characteristic of the age we live in. 'Without the aid of the vast accession to our power of producing perfect mechanism which it at once supplied,' says a first-class judge in matters of the kind, 'we could never have worked out into practical and profitable forms the conceptions of those master-minds who, during the past half-century, have so successfully pioneered the way for mankind. The steam-engine itself, which supplies us with such unbounded power, owes its present perfection to this most admirable means of giving to metallic objects the most precise and perfect geometrical forms. How could we, for instance, have good steam-engines if we had not the means of boring out a true cylinder, or turning a true piston-rod, or planing a valve-face?'
It would perhaps be impossible to cite any more authoritative estimate of Maudsley's invention than the above. The words placed between inverted commas are the words of James Nasmyth, the inventor of that wonderful steam-hammer which Professor Tomlin-son characterises as 'one of the most perfect of artificial machines and noblest triumphs of mind over matter that modern English engineers have yet developed.'[Pg 19]
Nasmyth's Steam-hammer.
This machine enlarged at one bound the whole scale of working in iron, and permitted Maudsley's lathe to develop its entire range of capacity. The old 'tilt-hammer' was so constructed that the more voluminous the material submitted to it, the less was the power attainable; so that as soon as certain dimensions had been [Pg 20] exceeded, the hammer became utterly useless. When the Great
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Western steamship was in course of construction, tenders were invited from the leading mechanical firms for the supply of the enormous paddle-shaft required for her engines. But a forging of the size in question had never been executed, and no firm in England would undertake the contract. In this dilemma, Mr Nasmyth was applied to, and the result of his study of the problem was this marvellous steam-hammer--so powerful that it will forge an Armstrong hundred-pounder as easily as a farrier forges a horse-shoe, and so delicately manageable that it will crack a nut without bruising its kernel!
