steel of great purity at a cost of less than £10 per ton, fully equal to that made from Swedish bar costing £30 per ton, such bar being only the raw material for the old crucible process of making steel.
From a consideration of these facts, it will be readily understood how we could produce cheap high- class tool steel, while for general uses we had obtained native pig-iron -- "Bessemer pig" -- smelted with coke, admirably adapted for the production of steel for all structural purposes, for which it was in every way superior to the highest brands of iron previously known in this country.
I had no sooner arrived at these results on a commercial scale than I again put myself in communication with Colonel Eardley Wilmot, the Superintendent of the Royal Gun Factory at Woolwich Arsenal, for I had never lost sight of the original object of my research a metal suitable for the construction of ordnance. It was, in fact, this idea that had led, step by step, to the discovery of my process. I was the more pleased to communicate these facts without delay to the authorities at Woolwich, because, in the person of Colonel Eardley Wilmot, I found a zealous officer, who took the deepest interest in any improved materials or processes that could be advantageously employed in the founding or construction of ordnance. He, fortunately, had no pet schemes of his own to promote, and was neither a patentee nor a private manufacturer; he was, in fact, an officer whose sole aim and ambition was to arrive at the highest perfection and development of the department over which he so ably presided, wholly without reference to the sources from which such improvements were derived.
It was now many months since I had reported myself at Woolwich, but on my communicating the fact that we were commercially successful in producing both pure and malleable iron in masses, and steel of any degree of carburisation that might be desired, at a price far below that of the best bar iron, and in masses of almost any assignable weight, the information immediately riveted Colonel Wilmot's attention. His old hopes of having a superior metal for guns seemed suddenly to revive, and he became deeply interested in all that I had to communicate. After a very protracted discussion, I left with a promise to send him several different qualities of our steel for analysis, testing for tensile strength, etc.
These investigations at Woolwich lasted over a period of several months, during which time I frequently called to see Colonel Wilmot, and sometimes to see Professor (afterwards Sir Frederick) Abel,1
who was at the head of the chemical laboratory, where a great number of analyses were, from time to time, made and communicated to me. Many interesting tests were also made by drawing down a portion of an ingot first, to two-tenths in additional length, and then to four-tenths, and so on. Some portions were elongated to five times their original length, each piece being tested to show the true amount of increased strength given to it by additional forging and elongation of the bar. In fact, Colonel Wilmot left no stone unturned to arrive at the actual facts of the case, and a full knowledge of the strength and properties of the new material. Some of the tests above mentioned have been lost, but I have still twenty- nine well-authenticated records showing the extreme tenacity and toughness of the metal. On one occasion I happened to remark to Colonel Wilmot that such was the extraordinary ductility of our cast malleable iron and mild cast steel, that I had no doubt a thick gun-tube might be collapsed, and hammered up quite flat, under the steam-hammer, whilst perfectly cold, without showing any tendency to crack or burst open. Colonel Wilmot observed that, notwithstanding the numerous proofs he had had of its marvellous tenacity, he thought that no material could possibly undergo such a severe ordeal without fracture. "Well," I said, "it will be an interesting experiment, even if it fails, and I will put it to the test if you wish it." I accordingly had an ingot of mild steel, and one of wholly decarburised iron, forged until they were extended to about double their original length. Two portions of each were cut off, turned, and bored in the lathe, and then beautifully finished both inside and out, the length and diameter of each cylinder being 6 in. and the thickness of metal 3/4 in. These pieces of gun-tube were bored to 4 1/2 in., in diameter -- a size suitable for a 40-pounder gun. I personally took these four tubes down to Woolwich, and was present with Colonel Wilmot when they were placed in succession (while cold) under the large steam hammer, and crushed flat, each tube being quite closed up. In no case was there the slightest indication of either tearing or rupture at any part of their surfaces.| Previous chapter/page | Back | Home | Email this | Search | Discuss | Bookmark | Next chapter/page |