Chapter 1

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CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY: PAPER 3

THE BEGINNINGS OF CHEAP STEEL

_Philip W. Bishop_

STEEL BEFORE THE 1850's 29

BESSEMER AND HIS COMPETITORS 30

ROBERT MUSHET 33

EBBW VALE AND THE BESSEMER PROCESS 35

MUSHET AND BESSEMER 37

WILLIAM KELLY'S AIR-BOILING PROCESS 42

CONCLUSIONS 46

THE BEGINNINGS OF CHEAP STEEL

By Philip W. Bishop

_Other inventors claimed a part in the invention of the Bessemer process of making steel. Here, the contemporary discussion in the technical press is re-examined to throw light on the relations of these various claimants to the iron and steel industry of their time, as having a possible connection with the antagonism shown by the ironmasters toward Bessemer's ideas._

THE AUTHOR: _Philip W. Bishop is curator of arts and manufactures, Museum of History and Technology, in the Smithsonian Institution's United States National Museum._

The development of the world's productive resources during the 19th century, accelerated in general by major innovations in the field of power, transportation, and textiles, was retarded by the occurrence of certain bottlenecks. One of these affected the flow of suitable and economical raw materials to the machine tool and transportation industries: in spite of a rapid growth of iron production, the methods of making steel remained as they were in the previous century; and outputs remained negligible.

In the decade 1855-1865, this situation was completely changed in Great Britain and in Europe generally; and when the United States emerged from the Civil War, that country found itself in a position to take advantage of the European innovations and to start a period of growth which, in the next 50 years, was to establish her as the world's largest producer of steel.

This study reviews the controversy as to the origin of the process which, for more than 35 years[1] provided the greater part of the steel production of the United States. It concerns four men for whom priority of invention in one or more aspects of the process has been claimed.

[1] From 1870 through 1907, "Bessemer" production accounted for not less than 50 percent of United States steel production. From 1880 through 1895, 80 percent of all steel came from this source: Historical Statistics of the United States 1789-1945 (Washington, U.S. Department of Commerce, Bureau of the Census, 1949), Tables J. 165-170 at p. 187.

The process consists in forcing through molten cast iron, held in a vessel called a converter, a stream of cold air under pressure. The combination of the oxygen in the air with the silicon and carbon in the metal raises the temperature of the latter in a spectacular way and after "blowing" for a certain period, eliminates the carbon from the metal. Since steel of various qualities demands the inclusion of from 0.15 to 1.70 percent of carbon, the blow has to be terminated before the elimination of the whole carbon content; or if the carbon content has been eliminated the appropriate percentage of carbon has to be put back. This latter operation is carried out by adding a precise quantity of manganiferous pig-iron (spiegeleisen) or ferromanganese, the manganese serving to remove the oxygen, which has combined with the iron during the blow.

The controversy which surrounded its development concerned two aspects of the process: The use of the cold air blast to raise the temperature of the molten metal, and the application of manganese to overcome the problem of control of the carbon and oxygen content.

Bessemer, who began his experiments in the making of iron and steel in 1854, secured his first patent in Great Britain in January 1855, and was persuaded to present information about his discovery to a meeting of the British Association for the Advancement of Science held at Cheltenham, Gloucestershire, in August 1856. His title "The Manufacture of Iron without Fuel" was given wide publicity in Great Britain and in the United States. Among those who wrote to the papers to contest Bessemer's theories were several claimants to priority of invention.

Two men claimed that they had anticipated Bessemer in the invention of a method of treating molten metal with air-blasts for the purpose of "purifying" or decarbonizing iron. Both were Americans. Joseph Gilbert Martien, of Newark, New Jersey, who at the time of Bessemer's address was working at the plant of the Ebbw Vale Iron Works, in South Wales, secured a provisional patent a few days before Bessemer obtained one of his series of patents for making cast steel, a circumstance which provided ammunition for those who wished to dispute Bessemer's somewhat spectacular claims. William Kelly, an ironmaster of Eddyville, Kentucky, brought into action by an American report of Bessemer's British Association paper, opposed the granting of a United States patent to Bessemer and substantiated, to the satisfaction of the Commissioner of Patents, his claim to priority in the "air boiling" process.

A third man, this one a Scot resident in England, intervened to claim that he had devised the means whereby Martien's and Bessemer's ideas could be made practical. He was Robert Mushet of Coleford, Gloucestershire, a metallurgist and self-appointed "sage" of the British iron and steel industry who also was associated with the Ebbw Vale Iron Works as a consultant. He, like his American contemporaries, has become established in the public mind as one upon whom Henry Bessemer was dependent for the origin and success of his process. Since Bessemer was the only one of the group to make money from the expansion of the steel industry consequent upon the introduction of the new technique, the suspicion has remained that he exploited the inventions of the others, if indeed he did not steal them.

In this study, based largely upon the contemporary discussion in the technical press, the relation of the four men to each other is re-examined and an attempt is made to place the controversy of 1855-1865 in focus. The necessity for a reappraisal arises from the fact that today's references to the origin of Bessemer steel[2] often contain chronological and other inaccuracies arising in many cases from a dependence on secondary and sometimes unreliable sources. As a result, Kelly's contribution has, perhaps, been overemphasized, with the effect of derogating from the work of another American, Alexander Lyman Holley, who more than any man is entitled to credit for establishing Bessemer steel in America.[3]

[2] See especially material distributed by the American Iron and Steel Institute in connection with its celebration of the centennial of Steel: "Steel centennial (1957), press information," prepared by Hill and Knowlton, Inc., and released by the Institute as of May 1, 1957.

[3] Holley's work is outside the scope of this paper. Belatedly, his biography is now being written. It can hardly fail to substantiate the contention that during his short life (1832-1882) Holley, who negotiated the purchase of the American rights to Bessemer's process, also adapted his methods to the American scene and laid a substantial part of the foundation for the modern American steel industry.

Steel Before the 1850's

In spite of a rapid increase in the use of machines and the overwhelming demand for iron products for the expanding railroads, the use of steel had expanded little prior to 1855. The methods of production were still largely those of a century earlier. Slow preparation of the steel by cementation or in crucibles meant a disproportionate consumption of fuel and a resulting high cost. Production in small quantities prevented the adoption of steel in uses which required large initial masses of metal. Steel was, in fact, a luxury product.

The work of Réaumur and, especially, of Huntsman, whose development of cast steel after 1740 secured an international reputation for Sheffield, had established the cementation and crucible processes as the primary source of cast steel, for nearly 100 years. Josiah Marshall Heath's patents of 1839, were the first developments in the direction of cheaper steel, his process leading to a reduction of from 30 to 40 percent in the price of good steel in the Sheffield market.[4] Heath's secret was the addition to the charge of from 1 to 3 percent of carburet of manganese[5] as a deoxidizer. Heath's failure to word his patent so as to cover also his method of producing carburet of manganese led to the effective breakdown of that patent and to the general adoption of his process without payment of license or royalty. In spite of this reduction in the cost of its production, steel remained, until after the midpoint of the century, an insignificant item in the output of the iron and steel industry, being used principally in the manufacture of cutlery and edge tools.

[4] Andrew Ure, _Dictionary of arts, manufactures and mines_, New York, 1856, p. 735.

[5] See abridgement of British patent 8021 of 1839 quoted by James S. Jeans, _Steel_, London, 1880, p. 28 ff. It is not clear that Heath was aware of the precise chemical effect of the use of manganese in this way.

The stimulus towards new methods of making steel and, indeed, of making new steels came curiously enough from outside the established industry, from a man who was not an ironmaster--Henry Bessemer. The way in which Bessemer challenged the trade was itself unusual. There are few cases in which a stranger to an industry has taken the risk of giving a description of a new process in a public forum like a meeting of the British Association for the Advancement of Science. He challenged the trade, not only to attack his theories but to produce evidence from their own plants that they could provide an alternative means of satisfying an emergent demand. Whether or not Bessemer is entitled to claim priority of invention, one can but agree with the ironmaster who said:[6] "Mr. Bessemer has raised such a spirit of enquiry throughout ... the land as must lead to an improved system of manufacture."

[6] _Mining Journal_, 1857, vol. 27, p. 465.

Bessemer and his Competitors

Henry Bessemer (1813-1898), an Englishman of French extraction, was the son of a mechanical engineer with a special interest in metallurgy. His environment and his unusual ability to synthesize his observation and experience enabled Bessemer to begin a career of invention by registering his first patent at the age of 25. His active experimenting continued until his death, although the public record of his results ended with a patent issued on the day before his seventieth birthday. A total of 117 British patents[7] bear his name, not all of them, by any means, successful in the sense of producing a substantial income. Curiously, Bessemer's financial stability was assured by the success of an invention he did not patent. This was a process of making bronze powder and gold paint, until the 1830's a secret held in Germany. Bessemer's substitute for an expensive imported product, in the then state of the patent laws, would have failed to give him an adequate reward if he had been unable to keep his process secret. To assure this reward, he had to design, assemble, and organize a plant capable of operation with a minimum of hired labor and with close security control. The fact that he kept the method secret for 40 years, suggests that his machinery[8] (Bessemer describes it as virtually automatic in operation) represented an appreciation of coordinated design greatly in advance of his time. His experience must have directly contributed to his conception of his steel process not as a metallurgical trick but as an industrial process; for when the time came, Bessemer patented his discovery as a process rather than as a formula.

[7] _Sir Henry Bessemer, F.R.S., an autobiography_, London, 1905, p. 332.

[8] _Ibid._, p. 59 ff.

In the light of subsequent developments, it is necessary to consider Bessemer's attitude toward the patent privilege. He describes his secret gold paint as an example of "what the public has had to pay for not being able to give ... security to the inventor" in a situation where the production of the material "could not be identified as having been made by any particular form of mechanism."[9] The inability to obtain a patent over the method of production meant that the disclosure of his formula, necessary for patent specification, would openly invite competitors, including the Germans, to evolve their own techniques. Bessemer concludes:[10]

Had the invention been patented, it would have become public property in fourteen years from the date of the patent, after which period the public would have been able to buy bronze powder at its present [_i.e._, _ca._ 1890] market price, viz. from two shillings and three pence to two shillings and nine pence per pound. But this important secret was kept for about thirty-five years and the public had to pay excessively high prices for twenty-one years longer than they would have done had the invention become public property in fourteen years, as it would have been if patented. Even this does not represent all the disadvantages resulting from secret manufacture. While every detail of production was a profound secret, there were no improvements made by the outside public in any one of the machines employed during the whole thirty-five years; whereas during the fourteen years, if the invention had been patented, there would, in all probability have been many improved machines invented and many novel features applied to totally different manufactures.

[9] _Ibid._, p. 82.

[10] _Ibid._, p. 83.

While these words, to some extent, were the rationalizations of an old man, Bessemer's career showed that his philosophy had a practical foundation; and, if this was indeed his belief, the episode explains in large measure Bessemer's later insistence on the legal niceties of the patent procedure. The effect of this will be seen.

Bessemer's intervention in the field of iron and steel was preceded by a period of experiments in the manufacture of glass. Here Bessemer claims to have made glass for the first time in the open hearth of a reverberatory furnace.[11] His work in glass manufacture at least gave him considerable experience in the problems of fusion under high temperatures and provided some support for his later claim that in applying the reverberatory furnace to the manufacture of malleable iron as described in his first patent of January 1855, he had in some manner anticipated the work of C. W. Siemens and Emil Martin.[12]

[11] _Ibid._, p. 108 ff.

[12] _Ibid._, p. 141. Bessemer's assertion that he had approached "within measurable distance" of anticipating the Siemens-Martin process, made in a paper presented at a meeting of the American Society of Mechanical Engineers (_Transactions of the American Society of Mechanical Engineers_, 1897, vol. 28, p. 459), evoked strong criticism of Bessemer's lack of generosity (_ibid._, p. 482). One commentator, friendly to Bessemer, put it that "Bessemer's relation to the open-hearth process was very much like Kelly's to the Bessemer process.... Although he was measurably near to the open-hearth process, he did not follow it up and make it a commercial success...." (_ibid._, p. 491).

The general interest in problems of ordnance and armor, stimulated by the Crimean War (1854-1856), was shared by Bessemer, whose ingenuity soon produced a design for a projectile which could provide its own rotation when fired from a smooth-bore gun.[13] Bessemer's failure to interest the British War Office in the idea led him to submit his design to the Emperor Napoleon III. Trials made with the encouragement of the Emperor showed the inadequacy of the cast-iron guns of the period to deal with the heavier shot; and Bessemer was presented with a new problem which, with "the open mind which derived from a limited knowledge of the metallurgy of war," he attacked with impetuosity. Within three weeks of his experiments in France, he had applied for a patent for "Improvements in the Manufacture of Iron and Steel."[14] This covered the fusion of steel with pig or cast iron and, though this must be regarded as only the first practical step toward the Bessemer process,[15] it was his experiments with the furnace which provided Bessemer with the idea for his later developments.

[13] British patent 2489, November 24, 1854.

[14] Bessemer, _op. cit._ (footnote 7), p. 137 He received British patent 66, dated January 10, 1855.

[15] See James W. Dredge, "Henry Bessemer 1813-1898," _Transactions of the American Society of Mechanical Engineers_, 1898, vol. 19, p. 911.

These were described in his patent dated October 17, 1855 (British patent 2321). This patent is significant to the present study because his application for an American patent, based on similar specifications, led to the interference of William Kelly and to the subsequent denial of the American patent.[16] In British patent 2321 Bessemer proposed to convert his steel in crucibles, arranged in a suitable furnace and each having a vertical tuyère, through which air under pressure was forced through the molten metal. As Dredge[17] points out, Bessemer's association of the air blast with the increase in the temperature of the metal "showed his appreciation of the end in view, and the general way of attaining it, though his mechanical details were still crude and imperfect."

[16] See U.S. Patent Office, Decision of Commissioner of Patents, dated April 13, 1857, in Kelly vs. Bessemer Interference. This is further discussed below (p. 42).

[17] Dredge, _op. cit._ (footnote 15), p. 912.

Experiments were continued and several more British patents were applied for before Bessemer made his appearance before the British Association on August 13, 1856.[18] Bessemer described his first converter and its operation in some detail. Although he was soon to realize that he "too readily allowed myself to bring my inventions under public notice,"[19] Bessemer had now thrown out a challenge which eventually had to be taken up, regardless of the strength of the vested interests involved. The provocation came from his claims that the product of the first stage of the conversion was the equivalent of charcoal iron, the processes following the smelting being conducted without contact with, or the use of, any mineral fuel; and that further blowing could be used to produce any quality of metal, that is, a steel with any desired percentage of carbon. Yet, the principal irritant to the complacency of the ironmaster must have been Bessemer's attack on an industry which had gone on increasing the size of its smelting furnaces, thus improving the uniformity of its pig-iron, without modifying the puddling process, which at best could handle no more than 400 to 500 pounds of iron at a time, divided into the "homeopathic doses" of 70 or 80 pounds capable of being handled by human labor.[20] Bessemer's claim to "do" 800 pounds of metal in 30 minutes against the puddling furnace's output of 500 pounds in two hours was calculated to arouse the opposition of those who feared the loss of capital invested in puddling furnaces and of those who suspected that their jobs might be in jeopardy. The ensuing criticism of Bessemer has to be interpreted, therefore, with this in mind; not by any means was it entirely based on objective consideration of the method or the product.[21]

[18] Bessemer's paper was reported in _The Times_, London, August 14, 1856. By the time the Transactions of the British Association were prepared for publication, the controversy aroused by Bessemer's claim to manufacture "malleable iron and steel without fuel" had broken out and it was decided not to report the paper. Dredge (_op. cit._, footnote 15, p. 915) describes this decision as "sagacious."

[19] Bessemer, _op. cit._ (footnote 7), p. 164.

[20] _The Times_, London, August 14, 1856.

[21] David Mushet recognized that Bessemer's great feature was this effort to "raise the after processes ... to a level commensurate with the preceding case" (_Mining Journal_, 1856, p. 599).

Within a month of his address, Bessemer had sold licenses to several ironmasters (outside Sheffield) and so provided himself with capital with which to continue his development work; but he refused to sell his patents outright to the Ebbw Vale Iron Works and by this action, as will be seen, he created an enemy for himself.

The three years between 1856 and 1859, when Bessemer opened his own steel works in Sheffield, were occupied in tracing the causes of his initial difficulties. There was continued controversy in the technical press. Bessemer (unless he used a _nom-de-plume_) took no part in it and remained silent until he made another public appearance before the Institution of Civil Engineers in London (May 1859). By this time Bessemer's process was accepted as a practical one, and the claims of Robert Mushet to share in his achievement was becoming clamorous.

Robert Mushet

Robert (Forester) Mushet (1811-1891), born in the Forest of Dean, Gloucestershire, of a Scots father (David, 1772-1847) himself a noted contributor to the metallurgy of iron and steel, is, like the American William Kelly, considered by many to have been a victim of Bessemer's astuteness--or villainy. Because of Robert Mushet's preference for the quiet of Coleford, many important facts about his career are lacking; but even if his physical life was that of a recluse, his frequent and verbose contributions to the correspondence columns of the technical press made him well-known to the iron trade. It is from these letters that he must be judged.

In view of his propensity to intervene pontifically in every discussion concerning the manufacture of iron and steel, it is somewhat surprising that he refrained from comment on Bessemer's British Association address of August 1856 for more than fourteen months. The debate was opened over the signature of his brother David who shared the family facility with the pen.[22] Recognizing Bessemer's invention as a "congruous appendage to [the] now highly developed powers of the blast furnace" which he describes as "too convenient, too powerful and too capable of further development to be superseded by any retrograde process," David Mushet greeted Bessemer's discovery as "one of the greatest operations ever devised in metallurgy."[23] A month later, however, David Mushet had so modified his opinion of Bessemer as to come to the conclusion that the latter "must indeed be classed with the most unfortunate inventors." He gave as his reason for this turnabout his discovery that Joseph Martien had demonstrated his process of "purifying" metal successfully and had indeed been granted a provisional patent a month before Bessemer. The sharp practice of Martien's patent lawyer, Mushet claimed, had deprived him of an opportunity of proving priority of invention against Bessemer. Mushet was convinced that Martien's was the first in the field.[24]