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 ]
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.
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."
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.
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 ]