The fly-wheel which the Cambria Company made for this engine interested me greatly. The hub and arms were cast in one piece as a spider and, of course, were free from internal strain. The rim was also cast in one piece. The manner in which the arms were united to the rim is shown in the accompanying cut. The spaces at the sides and end were ⁵⁄₈ inch wide; these were filled with oak, into which long slender steel wedges were driven from each side, as many as they would contain. This wonderful fly-wheel, I learned, was the invention of Mr. John Fritz, made while he was superintendent of the Cambria Works. The engine had many visitors, among whom I particularly remember Mr. Otis and Mr. Wellman, whom I happened to meet there. Their visit resulted in an order for an engine of the same size to drive the new plate-mill which Mr. Otis was about building. I received also three other orders for duplicates of this engine, one from the Pennsylvania Steel Company, one from the Bethlehem Steel Company, and a second order from the Cambria Company themselves. The order from the Bethlehem Steel Company was given me by Mr. John Fritz, then its superintendent and engineer, the inventor of the three-high train of rolls, and the designer of all their machinery for rolling both rails and armor-plates. An incident connected with the order from the Cambria Company I will mention, as showing the contrast between the brutal and the considerate way of doing business. I received a telegram from the Cambria Company, reading: “You are wanted here at once about another engine.” I learned afterward that this telegram as written by Mr. Powell Stackhouse, the general manager, did not contain the last three words, but read: “You are wanted here at once.” Mr. Stackhouse had written this telegram and laid it on his table for a boy to take to the telegraph operator. At that moment Mr. Jones came into his office and read the telegram, when the following conversation took place: _Mr. Jones_: “It will never do to send this in that shape.” _Mr. Stackhouse_: “Why not?” _Mr. Jones_: “It will break Porter all up.” _Mr. Stackhouse_: “How so?” _Mr. Jones_: “The only thing he can think of will be that some great disaster has happened to his engine.” No answer. Mr. Jones thereupon added the words “about another engine,” which changed somewhat the impression which the telegram was calculated to produce. [Illustration: JOHN FRITZ] These orders for four more engines of the largest size on my list were afterwards supplemented by a similar order from the Albany and Rensselaer Iron and Steel Company, making in all five, or with the one then running six from the same patterns.