The uniform success of my rolling-mill engines encouraged the Cambria Iron and Steel Company, of Johnstown, Penn., again on the advice of Mr. Holley, to order from me an engine to drive their rail-train. For this purpose I made the largest engine I had yet made, 40-inch cylinder by 48-inch stroke. It was altogether too large to be built in the Hewes & Phillips Iron Works, so I had the parts, except the valve-gear, constructed in three different establishments in Philadelphia. The bed, which weighed 40,000 pounds, was cast and finished at the I. P. Morris & Company’s works, the cylinder was cast and finished by Mr. James Moore, who also turned the shaft, and the crank-disk was turned and bored by William Sellers & Co. The several parts were not brought together until they met at Johnstown. The Cambria Company made their own fly-wheel. I spent considerable time while the work was in progress in traveling between Newark and Philadelphia, carrying measuring-rods, templets and gauges. I put the engine together myself, and everything came together without a hitch, which confirmed me in the belief that putting engines together and taking them down again in the shop was a great waste of time and space, and the manufacturing system which I was planning in my mind I intended should be wholly a manufacture of pieces to be kept in stock, and orders filled by shipment of the separate parts direct from the storehouse. The boilers at Johnstown were located over the heating furnaces, utilizing their waste heat, and were scattered all over the works. The largest steam-pipes were 8 inches in diameter. I gave them an order to make a steam-receiver 5 feet in diameter and 15 feet high, to be set close to the cylinder of the engine. They made it 18 feet high, the width of the sheets favoring this greater height. I took the steam by an 8-inch pipe entering at the top of this receiver and extending down 12 feet; from the top of the receiver I took the steam over to the engine by a 12-inch pipe. I drained the water from the bottom of this receiver by the largest Nason trap, from which a one-inch stream of water was delivered continually. I set in the side of this receiver four try-cocks, one above another four feet apart. From the lowest, six feet from the bottom, the steam blew as white as a sheet, from each one successively it blew with less color, and from the upper one it was quite invisible. I set a steam-gauge on this receiver, and it showed that when the greatest resistance was on the engine the pressure did not fall more than three pounds. This assurance of dry steam in the cylinder was vital to the success of the engine.