from the officials at Woolwich.Commander Minie, who had charge of the experiments which Bessemer was making on behalf of the Emperor of the French, said:
'Yes, the shots rotate properly; but if we cannot get something stronger for our guns, these heavy projectiles will be of little use.' This started Bessemer thinking and experimenting further, and led up, as we will see, to the great industrial revolution with which his name stands identified. He informed the Emperor that he intended to study the whole subject of metals suitable for artillery purposes. He built experimental works at St Pancras, but made many failures, furnace after furnace being pulled down and rebuilt. His prolonged and expensive experiments in getting a suitable ordnance metal were meanwhile using up his capital; but he was on the eve of a great discovery, and began to see that the refinement of iron might go on until pure malleable iron or steel could be obtained. His wife aided and encouraged him at this time as only a true wife can. After a year and a half, in which he patented many
improvements in the existing systems of manufacture, it occurred to him to introduce a blast of atmospheric air into the fluid metal, whereby the cast-iron might be made malleable. He found that by blowing air through crude iron in a fluid state, it could thus be rendered malleable. He next tried the method of having the air blown from below by means of an air-engine. Molten iron being poured into the vessel, and air being forced in from below, resulted in a surprising combustion, and the iron in the vessel was transformed into steel. The introduction of oxygen through the fluid iron, induced a higher heat, and burned up the impurities. Feeling that he
had succeeded in his experiment, he acquainted Mr George Rennie with the result. The[Pg 26] latter said to him: 'This must not be hid under a bushel. The British Association meets next week at Cheltenham; if you have patented your invention, draw up an account of it in a paper, and have it read in Section G.' Accordingly Bessemer wrote an account of his process, and in August 1856, he read his paper before the British Association 'On the Manufacture of Malleable Iron and Steel without Fuel,' which startled the iron trade of the country.
On the morning of the day on which his paper was to be read, Bessemer was sitting at breakfast in his hotel, when an iron-master to whom he was unknown, laughingly said to a friend: 'Do you know that there is somebody come down from London to read us a paper on making steel from cast-iron without fuel? Did you ever hear of such nonsense?'
Amongst those who spoke generously and enthusiastically of Bessemer's new process was James Nasmyth, to whom the inventor offered one-third share of the value of the patent, which would have been another fortune to him. Nasmyth had made money enough by this time, however, and declined.
7
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
