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In a communication to Nasmyth, Sir Henry Bessemer thanked him for his early patronage, and described his discovery: 'I shall ever feel grateful for the noble way in which you spoke at the meeting at Cheltenham of my invention. If I remember rightly, you held up a piece of malleable iron, saying words to this effect: "Here is a true British nugget! Here is a new process that promises to put an end to all puddling; and I may mention that at this moment there are puddling-furnaces in successful operation where my patent hollow steam-rabbler is at work, producing iron of superior quality by the introduction of jets of steam in the puddling process. I
do not, however, lay any claim[Pg 27] to this invention of Mr Bessemer; but I may fairly be entitled to say that I have advanced along the roads on which he has travelled so many miles, and has effected such unexpected results, that I do not hesitate to say that I may go home from this meeting and tear up my patent, for my process of puddling is assuredly superseded."'
After giving an account of his failures, as well as successes, Sir Henry proceeded to say: 'I prepared to try another experiment, in a crucible having no hole in the bottom, but which was provided with an iron pipe put through a hole in the cover, and passing down nearly to the bottom of the crucible. The small lumps and grains of iron were packed round it, so as nearly to fill the crucible. A
blast of air was to be forced down the pipe so as to rise up among the pieces of granular iron, and partly decarburise them. The pipe could then be withdrawn, and the fire urged until the metal with its coat of oxide was fused, and cast-steel thereby produced.
'While the blowing apparatus for this experiment was being fitted up, I was taken with one of those short but painful illnesses to which I was subject at that time. I was confined to my bed, and it was then that my mind, dwelling for hours together on the experiment about to be made, suggested that instead of trying to decarburise the granulated metal by forcing the air down the vertical pipe among the pieces of iron, the air would act much more energetically and more rapidly if I first melted the iron in the crucible, and forced the air down the pipe below the surface of the fluid metal, and thus burnt out the carbon and silicum which it contained.
'This appeared so feasible, and in every way so great an improvement, that the experiment on the granular pieces was at once abandoned, and as soon as I was well enough, I proceeded to try the experiment of forcing the air under the fluid metal. The result was marvellous.[Pg 28] Complete decarburation was effected in half an hour. The heat produced was immense, but unfortunately more than half the metal was blown out of the pot. This led to the use of pots with large, hollow, perforated covers, which effectually prevented the loss of metal. These experiments continued from January to October 1855. I have by me on the mantelpiece at this moment, a small piece of rolled bar-iron which was rolled at Woolwich Arsenal, and exhibited a year later at Cheltenham.
Bessemer Converting Vessel:
a, a, a, tuyeres; b, air-space; c, melted metal.
'I then applied for a patent, but before preparing my provisional specification (dated October 17, 1855), I searched for other patents to ascertain whether anything of the sort had been done before. I then found your[Pg 29] patent for puddling with the steam-rabble, and also Martin's patent for the use of steam in gutters while molten iron was being conveyed from the blast-furnace to a finery, there to be refined in the ordinary way prior to puddling.'
Several leading men in the iron trade took licenses for the new manufacture, which brought Bessemer PS27,000 within thirty days of the time of reading his paper. These licenses he afterwards bought back for PS31,000, giving fresh ones in their stead. Some of the early experiments failed, and it was feared the new method would prove impracticable. These experiments failed because of the presence of phosphorus in the iron. But Bessemer worked steadily in order to remove the difficulties which had arisen, and a chemical laboratory was added to his establishment, with a professor of chemistry attached. Success awaited him. The new method of steel-making spread into France and Sweden, and in 1879 the works for making Bessemer steel were eighty-four in number, and represented a capital of more than three millions. His process for the manufacture of steel raised the annual production of steel in England from 50,000 tons by the older processes to as many as 2,000,000 tons in some years. It was next used for boiler-plates; shipbuilding with Bessemer steel was begun in 1862, and now it is employed for most of the purposes for which malleable iron was formerly
used. The production of Europe and America in 1892 was over 10,000,000 tons, of a probable value of PS84,000,000, sufficient, as has been remarked, to make a solid steel wall round London 40 feet high, and 5 feet thick. It would take, according to the inventor, two or three years' production of all the gold-mines in the world to pay in gold for the output of Bessemer steel for one year. The price of steel previous to Huntsman's process was about PS10,000 per ton; after him,[Pg 30] from PS50 to PS100. Now Bessemer leaves it at PS5 to PS6 per ton. And a process which occupied ten days can be accomplished within half an hour.
Bessemer Process.
[Pg 31]
In his sketch of the 'Bessemer Steel Industry, Past and Present' (1894), Sir Henry Bessemer says: 'It is this new material, so much stronger and tougher than common iron, that now builds our ships of war and our mercantile marine. Steel forms their boilers,
their propeller shafts, their hulls, their masts and spars, their standing rigging, their cable chains and anchors, and also their guns and armour-plating. This new material has covered with a network of steel rails the surface of every country in Europe, and in America alone there are no less than 175,000 miles of Bessemer steel rails.' These steel rails last six times longer than if laid of iron.
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Bessemer was knighted in 1879, and has received many gold medals from scientific institutions. In addition he has, to use his own words, received in the form of royalties 1,057,748 of the beautiful little gold medals (sovereigns) issued by her Majesty's Mint. The method chosen by the Americans to perpetuate his name has been the founding of the growing centre of industry called Bessemer in Indiana, while Bessemer, in Pennsylvania, is the seat of the great Edgar Thompson steel-works. Thus the man who was at first
neglected by government has become wealthy beyond the dreams of avarice, and his name is immortal in the annals of our manufac-
turing industry.
SIR CHARLES WILLIAM SIEMENS AND THE SIEMENS PROCESS.
Another pioneer in the manufacture of steel and iron was Charles William Siemens, the seventh child of a German landowner, who was born at Lenthe, near[Pg 32] Hanover, 4th April 1823. He showed an affectionate and sensitive disposition while very young, and a strong faculty of observation. He received a good plain education at Lubeck, and in deference to his brother Werner he agreed to become an engineer, and accordingly was sent to an industrial school at Magdeburg in 1838, where he also learned languages, including English; mathematics he learned from his interested brother. He left Magdeburg in 1841 in order to increase his scientific knowledge at Gottingen, and there he studied chemistry and physics, with the view of becoming an engineer. Werner, his elder brother,
was still his good genius, and after the death of their parents counselled and encouraged him, and looked upon him as a probable future colleague. They corresponded with one another, not only about family affairs, but also about the scientific and technical subjects in which both were engrossed. This became a life-long habit with the brothers Siemens. One early letter from William described a new kind of valve-gearing which he had invented for Cornish steam-engines. Then the germ of the idea of what was afterwards known as the 'chronometric governor' for steam-engines was likewise communicated in this way. Mr Pole says that his early letters were significant of the talent and capacity of the writer. 'They evince an acuteness of perception in mechanical matters, a power of close and correct reasoning, a sound judgment, a fertility of invention, and an ease and accuracy of expression which, in a youth of nineteen, who had only a few months' experience in a workshop, are extraordinary, and undoubtedly shadow forth the brilliant future he attained in the engineering world.'
Werner in 1841 had taken out a patent for his method of electro-gilding, while William early in 1843 paid his first visit to England, travelling by way of Hamburg. He took up