Industrial Biography: Iron Workers and Tool Makers

by Samuel Smiles

Huntsman's experiments extended over many years before the desired result was achieved. Long after his death, the memorials of the numerous failures through which he toilsomely worked his way to success, were brought to light in the shape of many hundredweights of steel, found buried in the earth in different places about his manufactory. From the number of these wrecks of early experiments, it is clear that he had worked continuously upon his grand idea of purifying the raw steel then in use, by melting it with fluxes at an intense heat in closed earthen crucibles. The buried masses were found in various stages of failure, arising from imperfect melting, breaking of crucibles, and bad fluxes; and had been hid away as so much spoiled steel of which nothing could be made. At last his perseverance was rewarded, and his invention perfected; and though a hundred years have passed since Huntsman's discovery, the description of fuel (coke) which he first applied for the purpose of melting the steel, and the crucibles and furnaces which he used, are for the most part similar to those in use at the present day. Although the making of cast-steel is conducted with greater economy and dexterity, owing to increased experience, it is questionable whether any maker has since been able to surpass the quality of Huntsman's manufacture.

The process of making cast-steel, as invented by Benjamin Huntsman, may be thus summarily described. The melting is conducted in clay pots or crucibles manufactured for the purpose, capable of holding about 34 lbs. each. Ten or twelve of such crucibles are placed in a melting-furnace similar to that used by brass founders; and when the furnace and pots are at a white heat, to which they are raised by a coke fire, they are charged with bar steel reduced to a certain degree of hardness, and broken into pieces of about a pound each. When the pots are all thus charged with steel, lids are placed over them, the furnace is filled with coke, and the cover put down. Under the intense heat to which the metal is exposed, it undergoes an apparent ebullition. When the furnace requires feeding, the workmen take the opportunity of lifting the lid of each crucible and judging how far the process has advanced. After about three hours' exposure to the heat, the metal is ready for "teeming." The completion of the melting process is known by the subsidence of all ebullition, and by the clear surface of the melted metal, which is of a dazzling brilliancy like the sun when looked at with the naked eye on a clear day. The pots are then lifted out of their place, and the liquid steel is poured into ingots of the shape and size required. The pots are replaced, filled again, and the process is repeated; the red-hot pots thus serving for three successive charges, after which they are rejected as useless.

When Huntsman had perfected his invention, it would naturally occur to him that the new metal might be employed for other purposes besides clock-springs and pendulums. The business of clock-making was then of a very limited character, and it could scarcely have been worth his while to pursue so extensive and costly a series of experiments merely to supply the requirements of that trade. It is more probable that at an early stage of his investigations he shrewdly foresaw the extensive uses to which cast-steel might be applied in the manufacture of tools and cutlery of a superior kind; and we accordingly find him early endeavouring to persuade the manufacturers of Sheffield to employ it in the manufacture of knives and razors. But the cutlers obstinately refused to work a material so much harder than that which they had been accustomed to use; and for a time he gave up all hopes of creating a demand in that quarter. Foiled in his endeavours to sell his steel at home, Huntsman turned his attention to foreign markets; and he soon found he could readily sell abroad all that he could make. The merit of employing cast-steel for general purposes belongs to the French, always so quick to appreciate the advantages of any new discovery, and for a time the whole of the cast-steel that Huntsman could manufacture was exported to France. When he had fairly established his business with that country, the Sheffield cutlers became alarmed at the reputation which cast-steel was acquiring abroad; and when they heard of the preference displayed by English as well as French consumers for the cutlery manufactured of that metal, they readily apprehended the serious consequences that must necessarily result to their own trade if cast-steel came into general use. They then appointed a deputation to wait upon Sir George Savile, one of the members for the county of York, and requested him to use his influence with the government to obtain an order to prohibit the exportation of cast-steel. But on learning from the deputation that the Sheffield manufacturers themselves would not make use of the new steel, he positively declined to comply with their request. It was indeed fortunate for the interests of the town that the object of the deputation was defeated, for at that time Mr. Huntsman had very pressing and favourable offers from some spirited manufacturers in Birmingham to remove his furnaces to that place; and it is extremely probable that had the business of cast-steel making become established there, one of the most important and lucrative branches of its trade would have been lost to the town of Sheffield.

The Sheffield makers were therefore under the necessity of using the cast-steel, if they would retain their trade in cutlery against France; and Huntsman's home trade rapidly increased. And then began the efforts of the Sheffield men to wrest his secret from him. For Huntsman had not taken out any patent for his invention, his only protection being in preserving his process as much a mystery as possible. All the workmen employed by him were pledged to inviolable secrecy; strangers were carefully excluded from the works; and the whole of the steel made was melted during the night. There were many speculations abroad as to Huntsman's process. It was generally believed that his secret consisted in the flux which he employed to make the metal melt more readily; and it leaked out amongst the workmen that he used broken bottles for the purpose. Some of the manufacturers, who by prying and bribing got an inkling of the process, followed Huntsman implicitly in this respect; and they would not allow their own workmen to flux the pots lest they also should obtain possession of the secret. But it turned out eventually that no such flux was necessary, and the practice has long since been discontinued. A Frenchman named Jars, frequently quoted by Le Play in his account of the manufacture of steel in Yorkshire,[6] paid a visit to Sheffield towards the end of last century, and described the process so far as he was permitted to examine it. According to his statement all kinds of fragments of broken steel were used; but this is corrected by Le Play, who states that only the best bar steel manufactured of Dannemora iron was employed. Jars adds that "the steel is put into the crucible with A FLUX, the composition of which is kept secret;" and he states that the time then occupied in the conversion was five hours.

It is said that the person who first succeeded in copying Huntsman's process was an ironfounder named Walker, who carried on his business at Greenside near Sheffield, and it was certainly there that the making of cast-steel was next begun. Walker adopted the "ruse" of disguising himself as a tramp, and, feigning great distress and abject poverty, he appeared shivering at the door of Huntsman's foundry late one night when the workmen were about to begin their labours at steel-casting, and asked for admission to warm himself by the furnace fire. The workmen's hearts were moved, and they permitted him to enter. We have the above facts from the descendants of the Huntsman family; but we add the traditional story preserved in the neighbourhood, as given in a well-known book on metallurgy:—

"One cold winter's night, while the snow was falling in heavy flakes, and the manufactory threw its red glared light over the neighbourhood, a person of the most abject appearance presented himself at the entrance, praying for permission to share the warmth and shelter which it afforded. The humane workmen found the appeal irresistible, and the apparent beggar was permitted to take up his quarters in a warm corner of the building. A careful scrutiny would have discovered little real sleep in the drowsiness which seemed to overtake the stranger; for he eagerly watched every movement of the workmen while they went through the operations of the newly discovered process. He observed, first of all, that bars of blistered steel were broken into small pieces, two or three inches in length, and placed in crucibles of fire clay. When nearly full, a little green glass broken into small fragments was spread over the top, and the whole covered over with a closely-fitting cover. The crucibles were then placed in a furnace previously prepared for them, and after a lapse of from three to four hours, during which the crucibles were examined from time to time to see that the metal was thoroughly melted and incorporated, the workmen proceeded to lift the crucible from its place on the furnace by means of tongs, and its molten contents, blazing, sparkling, and spurting, were poured into a mould of cast-iron previously prepared: here it was suffered to cool, while the crucibles were again filled, and the process repeated. When cool, the mould was unscrewed, and a bar of cast-steel presented itself, which only required the aid of the hammerman to form a finished bar of cast-steel. How the unauthorized spectator of these operations effected his escape without detection tradition does not say; but it tells us that, before many months had passed, the Huntsman manufactory was not the only one where cast-steel was produced." [7]

However the facts may be, the discovery of the elder Huntsman proved of the greatest advantage to Sheffield; for there is scarcely a civilized country where Sheffield steel is not largely used, either in its most highly finished forms of cutlery, or as the raw material for some home manufacture. In the mean time the demand for Huntsman's steel steadily increased, and in 1770, for the purpose of obtaining greater scope for his operations, he removed to a large new manufactory which he erected at Attercliffe, a little to the north of Sheffield, more conveniently situated for business purposes. There he continued to flourish for six years more, making steel and practising benevolence; for, like the Darbys and Reynoldses of Coalbrookdale, he was a worthy and highly respected member of the Society of Friends. He was well versed in the science of his day, and skilled in chemistry, which doubtless proved of great advantage to him in pursuing his experiments in metallurgy.[8] That he was possessed of great perseverance will be obvious from the difficulties he encountered and overcame in perfecting his valuable invention. He was, however, like many persons of strong original character, eccentric in his habits and reserved in his manner. The Royal Society wished to enrol him as a member in acknowledgment of the high merit of his discovery of cast-steel, as well as because of his skill in practical chemistry; but as this would have drawn him in some measure from his seclusion, and was also, as he imagined, opposed to the principles of the Society to which he belonged, he declined the honour. Mr. Huntsman died in 1776, in his seventy-second year, and was buried in the churchyard at Attercliffe, where a gravestone with an inscription marks his resting-place.

His son continued to carry on the business, and largely extended its operations. The Huntsman mark became known throughout the civilised world. Le Play the French Professor of Metallurgy, in his Memoire of 1846, still speaks of the cast-steel bearing the mark of "Huntsman and Marshall" as the best that is made, and he adds, "the buyer of this article, who pays a higher price for it than for other sorts, is not acting merely in the blind spirit of routine, but pays a logical and well-deserved homage to all the material and moral qualities of which the true Huntsman mark has been the guarantee for a century." [9]

Many other large firms now compete for their share of the trade; and the extent to which it has grown, the number of furnaces constantly at work, and the quantity of steel cast into ingots, to be tilted or rolled for the various purposes to which it is applied, have rendered Sheffield the greatest laboratory in the world of this valuable material. Of the total quantity of cast-steel manufactured in England, not less than five-sixths are produced there; and the facilities for experiment and adaptation on the spot have enabled the Sheffield steel-makers to keep the lead in the manufacture, and surpass all others in the perfection to which they have carried this important branch of our national industry. It is indeed a remarkable fact that this very town, which was formerly indebted to Styria for the steel used in its manufactures, now exports a material of its own conversion to the Austrian forges and other places on the Continent from which it was before accustomed to draw its own supplies.

Among the improved processes invented of late years for the manufacture of steel are those of Heath, Mushet, and Bessemer. The last promises to effect before long an entire revolution in the iron and steel trade. By it the crude metal is converted by one simple process, directly as it comes from the blast-furnace. This is effected by driving through it, while still in a molten state, several streams of atmospheric air, on which the carbon of the crude iron unites with the oxygen of the atmosphere, the temperature is greatly raised, and a violent ebullition takes place, during which, if the process be continued, that part of the carbon which appears to be mechanically mixed and diffused through the crude iron is entirely consumed. The metal becomes thoroughly cleansed, the slag is ejected and removed, while the sulphur and other volatile matters are driven off; the result being an ingot of malleable iron of the quality of charcoal iron. An important feature in the process is, that by stopping it at a particular stage, immediately following the boil, before the whole of the carbon has been abstracted by the oxygen, the crude iron will be found to have passed into the condition of cast-steel of ordinary quality. By continuing the process, the metal losing its carbon, it passes from hard to soft steel, thence to steely iron, and last of all to very soft iron; so that by interrupting the process at any stage, or continuing it to the end, almost any quality of iron and steel may be obtained. One of the most valuable forms of the metal is described by Mr. Bessemer as "semi-steel," being in hardness about midway between ordinary cast-steel and soft malleable iron. The Bessemer processes are now in full operation in England as well as abroad, both for converting crude into malleable iron, and for producing steel; and the results are expected to prove of the greatest practical utility in all cases where iron and steel are extensively employed.