Now I took heart and set at work in earnest, feeling sure that I could soon bring the engine into a position that would command the means required to do it justice. I ordered from Smith & Coventry a stationary drilling machine, a 6-inch slotting machine, a bolt-threading machine, and a set of cylindrical gauges, and had them all in place by the time we were ready to use them. This bolt-threading machine was a wonder, and has not been surpassed since. The rod was fed through a hollow spindle, seized in the jaws of a self-centering chuck, and the projecting end finished. The threading dies were backed by eccentric wedges in a solid ring, which was turned out of the way during the sliding operation. These were closed or opened by a lever which carried a stud moving in a circular slot. This stud was brought up to a stop, which could be set to cut threads of any depth. The threads were finished in a single motion. For standing bolts, we threaded one end, so that it screwed hard into its seat, and by moving the stop a trifle the threads on the other end were cut deeper, so that the nuts turned on it more easily. The rapidity, uniformity and precision with which this was done could not be surpassed. Smith & Coventry had lately commenced the manufacture of cylindrical gauges, of which up to that time Mr. Whitworth had had the monopoly. Flat gauges did not then exist. The above tools were almost incredibly superior to those then made in this country. I was anxious for one of their radial drills, but had no place to set it. I adopted the Franklin Institute screw-thread, and obtained a set of hobs from William Sellers & Co. I equipped our little office to accommodate one draftsman besides myself, and soon had a good man at work, engaged mostly in preparing drawings from the tracings I had brought from England. The story over the shop, in the middle half of which a man could stand upright, was made a pattern shop, and two patternmakers were soon at work there. They found the shop very hot. The roof was covered with paper and tar. I could not bear my hand on the under side of the roof boards. I whitewashed the roof, making the whitewash rainproof, and this heat entirely disappeared. I have borne in mind this interesting result, the complete prevention of heat absorption by changing the color of the surface to one absolutely white; and am now proposing a similar change in brick boiler settings and chimneys, using white enameled tiles, which also prevent percolation of the external air.