Two of my English engineering acquaintances appeared at this exhibition. One of them was a judge in the group which embraced sewing machines. I remember asking him what was the most interesting mechanical device he had seen at the exhibition; he told me it was the automatic tension in the Wilcox & Gibbs sewing machine. In a walk with him through Machinery Hall one day, I called his attention to a locomotive built by the Baldwin Locomotive Works. After looking it over cursorily he remarked that he did not see anything particular in it. I could not help replying, “That may not be the fault of the locomotive.” I had thought him a light weight in England, and that superficial remark confirmed my opinion. The other friend, as I am proud to call him, I have always considered mechanically the most interesting man I ever met. It was Mr. Smith, of Smith & Coventry, the machine-tool builders of Salford. Mr. Smith was the brains of the concern. He had come over to learn what America could teach him, and the only thing he took back, so far as I know, was the twist-drill, the manufacture of which was begun by that firm after his return. I shall have something to add later to what I have already said respecting his wonderful improvements in machine tools. In one of the pleasant walks we took together, our attention was arrested by the exhibit of Riehlé Brothers, the celebrated scale manufacturers of Philadelphia. Among other novel and interesting features of their exhibit this firm showed a ³⁄₄-inch bolt broken by a stress applied to it through a nut of only one half the standard thickness, or three eighths of an inch deep, and that run on loosely by hand. This astonishing revelation drew from Mr. Smith the ejaculation, “Why, old Whitworth lied.” Mr. Whitworth had stated that he had ascertained by experiment that a nut to be as strong as the bolt must have a depth equal to the diameter of the bolt, and this had been accepted as mechanical truth by the entire engineering world, no one ever thinking to make the simple measurement which would show that the force required to strip the threads of any bolt in a nut of this standard depth would be nearly three times the strength of the bolt. He was, of course, highly interested in the wonderful steelyards made by this firm, which would weigh anything that could be lifted by a crane. His only discovery respecting machine tools was, that their manufacture in the United States was generally very inferior.
It was fortunate that I had prepared the drawings according to my revised model for three or four sizes of the engines, as otherwise I should not have been able to accept the position offered me at the Philadelphia exposition. I received two more orders before May 24, and two more during the summer, but with the preparations I had made and Mr. Goodfellow’s familiarity with the work, everything went on smoothly during my absence.
CHAPTER XXIV
Engine Building in Newark. Introduction of Harris Tabor.
After my return from Philadelphia the first order I received was a very important one. On the advice of Mr. Holley, the Albany and Rensselaer Iron and Steel Co. of Troy, N. Y., decided to order from me two engines for the new roll trains they were about to establish; this being the first opportunity I had of applying my engine in what proved to be its most important field. These were a 22×36-inch engine to drive a 16-inch train for rolling light steel rails, and an 18×30-inch engine to drive an 8- or 10-inch train for rolling merchant steel. These engines did not run rapidly; the first was a direct-connected engine making only 75 revolutions per minute; the second made only 112 revolutions per minute, but was belted to drive the train at twice that speed.
Mr. Corning, president of the company, did not like the slow way in which the rails were turned out of the former train. I happened to be standing with him observing this work when he asked a boy why the billets were not fed to the rolls faster. The boy replied, “Because the gentlemen at the hooks could not catch them, sir.” Where are the gentlemen at the hooks to-day, when rails 200 feet long are turned out of the rolls?
These engines stood near each other, the trains extending in opposite directions. The battery of boilers was located at a considerable distance from them. I set between them a vertical steam receiver, four feet in diameter and twelve feet high. This receiver performed two functions: it maintained the steam pressure at the cylinders and separated the steam from the water carried over. This latter was accomplished by admitting the steam at the top of the receiver by a pipe extending two thirds of the way to the bottom, draining the water from the bottom by means of a Nason steam trap, and taking the dry steam to the engine from the top of the receiver. This was my first application of this method, which afterwards proved most valuable in cases of greater importance. These engines were of the highest interest to me, as their successful running opened the door to that important field.
While they were still lying on the floor of the shop ready for shipment, I had an opportunity of submitting them to the criticism of William R. Jones, the manager of the Edgar Thompson Steel Works, to whom, as already related, I had sold a small engine and governors for his large ones. I had not made these engines properly in one respect, as he pointed out to me that, for rolling-mill uses, they must be made capable of being run backwards by hand from any position, a requirement of which I had been ignorant. I soon made the necessary additions to the valve-gear which enabled this to be done. I never knew how Mr. Jones came to make this opportune visit, but undoubtedly Mr. Holley sent him.
I had another visitor before these engines were shipped. It was the manager of the Laclede rolling mill at St. Louis, accompanied by his engineer. They had designed a system of driving several trains of rolls from one engine, the power of which was to be transmitted through gearing. They were greatly fascinated by the appearance of the engines, and gave me an order for a large engine on the spot.