The following incident illustrates the general intelligence on this subject at that time among skilled workmen in this country. As I was inspecting Mr. Meyers’ first work in scraping, my foreman came along, and after observing it quite a while remarked, “It is my opinion you will never make a proper job of that, till you put it on the planer and take a light cut over it.” One day, not long after we started, George Goodfellow walked into my shop. He had come from the Whitworth works, had been foreman there of the upstairs room in which most of the fine scraping on their tools was done. I had a slight acquaintance with him, but could not remember having been in his room but once, and then only for a minute or two. He had become disgusted with Mr. Widdowson and the way things were going on under his management, and had resigned his position and emigrated to the United States; found out where I was hiding, I never learned how, and applied to me for a job, which I was glad to give him. I cannot imagine any greater contrast than between Mr. Goodfellow and every other man I met in the Whitworth shops. I had then on hand two orders for standard surface plates and straight edges, one from the Colt Armory and one from Pratt & Whitney. Mr. Meyers had just finished work on these when Mr. Goodfellow appeared. He had not been at work in the shop but a day or two when he asked me if I had got the cross-wind out of those straight edges. I made him the ignorant answer that they were so narrow the matter of cross-wind had not occurred to me as important, as our planer did very true work. He said nothing, but pulled a hair out of his head and laid it across a straight edge at its middle point. He then inverted another straight edge on it and swung this on the hair as a pivot. It swung in one direction freely, but in the other direction the corners caught and it was revealed that the surfaces were spirals. I gave him the job of taking out this twist. He was occupied about two days in making the three interchangeable straight edges quite true. When finished I tried them with great satisfaction, the test showing also their absolute freedom from flexure. The first swing on the hair pivot was in each direction as if the upper straight edge were hanging in the air. As this was repeated back and forth, I felt the surfaces gradually approaching each other, the same increasing resistance being felt in each direction of the swing, and finally they were in complete contact. What became of the hair I could not find out. This refinement of truth, so easily attained and demonstrated when we know how, was of course a necessity. I made the engines at that time with the steam-chest separate from the cylinder; so two long steam joints had to be made between cylinder, chest, and cover.