I believe, however, that there is yet a future for the inclined boiler tube, with independent circulation in each tube, the whole made entirely from forged steel; and that better results will be obtained from it than any other form of boiler has as yet given. I have been told by Chief Engineer Melville that all water admitted to the boilers in the United States Navy is made pure enough for pharmaceutical purposes. If this can be done in the navy, where sea water and the mud of harbors have to be used, it can be done anywhere. Cooling towers make it practicable to return all water to the boiler even from non-condensing engines. Then only the waste needs to be made good, and any water can be purified for this purpose. Oil or grease with the feed-water is readily avoided. Only electrolysis remains to be provided against, which can be done by avoiding the use of any alloy of copper in contact with the water. We may then have boilers of the most durable character and safe to carry any desired pressure. The following incident near the close of my experience in Harlem would be too ridiculous to print except for its consequence. One day Mr. Smith sent me word that he would like to see me in his office. When I entered he asked me, “What do you pay for the castings of your governor arms and balls?” Of course he knew perfectly well, as he had the bills and the books, but that was his way of introducing the subject. I replied, “Forty cents a pound.” He held up both hands in affected amazement, and exclaimed, “Forty cents a pound! Well, sir, I can assure you of one thing, no more of this company’s money is going to be squandered in that way.” I overlooked his insulting language and manner, and said quietly, “Are you sure, Mr. Smith, that you have all the information you need to form a correct judgment in this matter?” “I am sure,” he replied, “what the market price is of copper and tin, and that I can get castings made from our own metal at a price that will bring the cost to not more than 25 cents a pound.” “This, then, I presume, is all you know about the subject,” I said, “and you ought to know a great deal more, which I will tell you. It is necessary that I can rely upon getting a pure copper and tin alloy, in the proportion known as gun-metal, on account of its strength, its rigidity, and its wearing qualities. The latter is of especial importance, because the governor joints are in continual motion under the weight of the heavy counterpoise. Experience shows that this purity cannot be relied upon where it is possible that any inferior metal can become mixed with this alloy in even the smallest proportion. This for us, not making our own castings, must be wholly a matter of confidence.