Only a few years had passed, and self-acting tools were now enabled to complete, with precision and uniformity, machines that before had been deemed almost impracticable.
In proportion to the rapid extension of railways the demand for locomotives became very great. As our machine tools were peculiarly adapted for turning out a large amount of first-class work, we directed our attention to this class of business. In the course of about ten years after the opening of the Liverpool and Manchester Railway, we executed considerable orders for locomotives for the London and Southampton, the Manchester and Leeds, and the Gloucester railway companies.
The Great Western Railway Company invited us to tender for twenty of their very ponderous engines. They proposed a very tempting condition of the contract. It was, that if, after a month's trial of the locomotives, their working proved satisfactory, a premium of #100 was to be added to the price of each engine and tender. The locomotives were made and delivered; they ran the stipulated number of test miles between London and Bristol in a perfectly satisfactory manner; and we not only received the premium, but, what was much more encouraging, we received a special letter from the Board of Directors, stating their entire satisfaction with the performance of our engines, and desiring us to refer other contractors to them with respect to the excellence of our workmanship. This testimonial was altogether spontaneous, and proved extremely valuable in other quarters.
I may mention that, in order to effect the prompt and perfect execution of this order, I contrived several special machine tools, which assisted us most materially. These tools for the most part rendered us more independent of mere manual strength and dexterity, while at the same time they increased the accuracy and perfection of the work. They afterwards assisted us in the means of perfecting the production of other classes of work. At the same time they had the important effect of diminishing the cost of production, as was made sufficiently apparent by the balance-sheet prepared at the end of each year. My connection with the Great Western Company shortly led to a most important event in connection with my own personal history. It appears that their famous steam-ship the Great Western had been very successful in her voyages between Bristol and New York; so much so, indeed, that the directors of the Company ordered the construction of another vessel of much greater magnitude--the Great Britain. Mr. Francis Humphries, their engineer, came to Patricroft to consult with me as to the machine tools, of unusual size and power, which were required for the construction of the immense engines of the proposed ship, which were to be made on the vertical trunk principle. Very complete works were erected at Bristol for the accommodation of the requisite machinery. The tools were made according to Mr. Humphries' order; they were delivered and fitted to his entire approval, and the construction of the gigantic engines was soon in full progress.
An unexpected difficulty, however, was encountered with respect to the enormous wrought-iron intermediate paddleshaft. It was required to be of a size and diameter the like of which had never been forged. Mr. Humphries applied to the largest forges throughout the country for tenders of the price at which they would execute this important part of the work, but to his surprise and dismay he found that not one of them could undertake so large a forging. In this dilemma he wrote a letter to me, which I received on the 24th of November 1839, informing me of the unlooked-for difficulty. "I find," he said, "that there is not a forge hammer in England or Scotland powerful enough to forge the intermediate paddle-shaft of the engines for the Great Britain! What am I to do? Do you think I might dare to use cast-iron?
This letter immediately set me a-thinking. How was it that the existing hammers were incapable of forging a wrought-iron shaft of thirty inches diameter? Simply because of their want of compass, of range and fall, as well as of their want of power of blow. A few moment's rapid thought satisfied me that it was by our rigidly adhering to the old traditional form of a smith's hand hammer-- of which the forge and tilt hammer, although driven by water or steam power, were merely enlarged modifications--that the difficulty had arisen; as, whenever the largest forge hammer was tilted up to its full height, its range was so small that when a piece of work of considerable size was placed on the anvil, the hammer became "gagged;" so that, when the forging required the most powerful blow, it received next to no blow at all, as the clear space for the fall of the hammer was almost entirely occupied by the work on the anvil.
The obvious remedy was to contrive some method by which a ponderous block of iron should be lifted to a sufficient height above the object on which it was desired to strike a blow, and then to let the block full down upon the forging, guiding it in its descent by such simple means as should give the required precision in the percussive action of the falling mass following up this idea, I got out my "Scheme Book," on the pages of which I generally thought out, with the aid of pen and pencil, such mechanical adaptations as I had conceived in my mind, and was thereby enabled to render them visible. I then rapidly sketched out my Steam Hammer, having it all clearly before me in my mind's eye. In little more than half an hour after receiving Mr. Humphries' letter narrating his unlooked-for difficulty, I had the whole contrivance in all its executant details, before me in a page of my Scheme Book, a reduced photographed copy of which I append to this description. The date of this first drawing was the 24th November, 1839.
[Image] First drawing of steam hammer, 24th Nov. 1839
