Pig iron, which is highly carbonized iron from the blast furnace, was laboriously converted into malleable iron by the old process of the puddling furnace. Bessemer conceived the process of forcing air among the particles of molten iron, and by a single operation, combining the use of air in the double purpose of increasing temperature, and removing the carbon. The carbon of the iron has a greater affinity for the oxygen of the air than for the iron. When all the carbon is removed, then exactly enough carbon is added by introducing molten spiegeleisen to produce steel of any desired temper with the utmost certainty.
With the ordinary kinds of pig iron early in use, Bessemer's process was powerless. The old puddling process was more capable of removing phosphorus and sulphur. But with pig iron produced from the red hematite ores, practically free from phosphorus, Bessemer's process was a surprising success.
At once exploration began to open vast fields of hematite ores in the counties of Cumberland and Lancashire of England, in Spain, in the Lake Superior regions of North America, and in other countries. Bessemer wisely made his royalty very low, five dollars per ton; capital rapidly flowed into this new industry, and Bessemer won a fortune. Mushroom towns and cities sprung up everywhere and fortunes were made by many.
Mr. Bessemer himself vividly described his process in action: "When the molten pig iron is poured into mortar-like converters, supported on trunions like a cannon, the process is brought into full activity. The blast is admitted through holes in the bottom, when small powerful jets of air spring upward through the boiling fluid mass, and the whole apparatus trembles violently. Suddenly a volcano-like eruption of flames and red-hot cinders or sparks occurs. The roaring flames, rushing from the mouth of the converter, changes its violet color to orange and finally to pure white. The large sparks change to hissing points, which gradually become specks of soft, bluish light as the state of malleable iron is approached."
This very brilliant process, which includes the introduction and mixture of the spiegeleisen, may occupy fifteen minutes, when the moulds are filled, and the steel ingots can be hammered or rolled the same as blooms from a puddling furnace.
Mr. Bessemer explained many things, and offered many valuable suggestions. A remark of Mr. Bessemer to George Ingram led the latter to tell Bessemer a story which he heard in the smoking-room of the S.S. "Campania."
"Two Irishmen once tried to sleep, but could not for Jersey mosquitoes had entered their bedroom. Earnest effort drove the mosquitoes out, and the light was again extinguished. Soon Mike saw a luminous insect, a big fire-fly approaching. Quickly he roused his companion saying, 'Pat, wake up! Quick! Let's be going! It's no use trying to get more sleep here, there comes another Jersey mosquito hunting us with a lantern.'"
Mr. Bessemer was amused, and he ventured the assertion that when electricity could be as cheaply produced directly from coal as the light by the fire-fly, and successfully delivered in our great cities, the smoke nuisance would be effectually abated, all freight charges on coal would be saved, and coal operators could utilize all their slack at the mines.
"Do you think this possible?" inquired Colonel Harris.
"Oh, yes, quite possible," answered Bessemer, "our necessities beget our inventions and discoveries. Thorough investigation in the near future on this and kindred lines must be fruitful of astonishing results in the interests of a higher civilization." The colonel and George took their leave. Truly the fire-fly, like the whirling hot nail, is suggestive of great possibilities, thought George.