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tubes an hour can be cleaned in this way, removing every particle of scale, no matter how thick or how hard the incrustration may be. The device, for test, and full litera- ture explaining it, will be sent on re- quest by the company. MAIN VALVES ON THE STEAM ENGINE. The steam engine cannot be cal'ed new. Therefore, the functions of the main valves should be quite well un- derstood by those who are yet build- ing or buying or operating the steam engine. The function of the main valve being to open the port for the freest admission of the desired quan- tity of steam, then to cleanly cut off this quantity from the supply and confine it in the cylinder (without leakage) that it may push on the piston to the last possible degree, then open and allow it to escape as freely and, therefore, speedily as pos- sible, it is absolutely necessary that in order to perform these functions properly the valve must be steam tight on its seats and must remain steam tight until worn out, for, if it leaks, it simply acts upon the engine, as choking would upon a man who was trying to run up hill, increasing leakage representing a tightening grip upon the man's throat. For two rea- sons the valve must move without friction, Hirst, if cannot. emai steam tight if it wears itself and seats by friction, and, second, it cannot maintain its proper movements if the valve motion is under heavy strain, and worn excessively by valve friction; there- fore, to have an efficient main valve it must be correctly (completely) balanced, and of a design which will maintain it- self steam tight. It must also take care of any excess of water that may get into the cylinder. While this may ap- pear very simple, it is only necessary to examine the patent records to discover that the vast amount of thought by hundreds of mechanics which has been given to the question, stamps Aiaeea Se most perplexing problem: The first re- corded attempt was. made by J. Kirk- patrick, July 10, 1834, (73 years ago) since which time 1,000 patents issued to those who have attempted, in many ways, to produce a main valve that would move on its seat without friction, that would be and remain steam tight until worn out and that would relieve the cylinders of excess water. : Most of these thousand improved main valves never reached or got beyond the first trial, and those few which have stood the test of service have only done so. imperfectly under far more favorable conditions than the present high pres- TAE MarRINE REVIEW sures and superheated 'steam presents, and they fail utterly to- meet these modern requirements. One fails to find anyone of those who attempted to solve this question giving 'more than a few spare moments of their time to it, they all being more or less weighted with, what was to them, more important work. None of them made a special exclusive business of it, and very few ever gave it attention beyond the trial of the device they had so conceived, and, as the first of any mechanical device was never perfect, there was disappoint- ment, and there the question rested: the cause of so many and so general failures was due to lack of continued effort in the one direction by the same individual. Like the others, the American Balance * Valve Co. started in the valve business with the expectation of giving it only a part of their time, but, unlike others, did not stop with their first imperfect test, but recognized the importance of the task, and prepared to devote their entire time to its solution. They, therefore, sent to Washington, and had the entire series of main valve patents bound in six large volumes and forwarded to their office. After examining these carefully the cause of failure was clear.. They kept in mind the two absolutely neces- sary features of perfect balance at all points in the valve's movement, and abso- lutely steam tight, self-adjusting packing. They found almost all sadly deficient in both of these essentials, and the remain- ing few either devoid of or sadly defi- cient in one or the other. Some few men may honestly believe (if they haven't made proper tests) that they can fit a round plug into a valve cage so it will accommodate itself to the changing tem- peratures and not stick nor become loose enough to leak. Others will say they can do this thing with a square or flat valve in a hole of same shape, with some- times a means provided for adjusting the hole, such as set screws or shims, or facing of lug, etc. They convinced themselves, as most mechanics have done, that none of these propositions were worth considering as balanced steam tight valves for steam engines. They recognized, as an absolute fact, that any valve in which the combination of the packing and the valve did not auto- matically adjust the valve to its seat or cage, and then automatically continue this adjustment, was a poor and expen- sive valve. The fact that engines have been built, are being built, and will continue to come forth with valves of poor efficiency, does not speak in favor of such valves, for it is only a question of boiler behind them to enable the engine to perform a given work for a time, but it must be noticed that they require frequent refit- 69 ting in order to prevent the ever-increas- ing waste of steam overreaching the ca- pacity of the boiler and seriously affect. ing the power of the engine. There is no investment that can be placed on an engine that will begin to give as great returns through increased efficiency of both engine and boiler as the most per- fect balanced main valve obtainable, and this fact alone, is sufficient to cause every builder, purchaser or operator of a steam engine to give the question suffi- cient attention to insure the use of the best that is in the market. STEERING GEAR CHAIN. In order to give closer attention to their growing lake trade on steering-gear chain and forgings, the Jas. McKay Co., of Pittsburg, has opened a Cleveland of- fice at 1014 Citizens building with H. D. Cushman Co. in charge, through whom their local business will in the future be - transacted. For 30 years this firm has produced high grade, hand-welded, test- ed chains and their product is widely known and extensively used by railroads, dredgemen, vesselmen and wherever life or property is dependent on chain. They borst with pardonable pride that not a single life has been lost through defects in material or workmanship in their chain. are The safety of a modern vessel demands wheel chains of highest tested quality and for this purpose Jas. McKay Co, manufactures chain from Zug's staybolt or Ulster iron, hand welded on a coke fire and tested to meet the specifications of the United States government, Lloyds and the American Bureau Veritas. A certificate of inspection is furnished with each chain. EQUIPMENT FOR REVENUE CUTTER SERVICE. Amongst the recent orders filled for the government by the Woodhouse Ghain Works, Trenton Ne jis 2 40- fathom cable for revenue cutter No. 14, now building at the yard of Pusey & Jones, Wilmington, Del. The chain is of studded-link type, 1 9-16 in. diameter, and under breaking test withstood an actual strain of 139,790 lbs.; the test being certified to by the assistant engineer of the reve- nue cutter service. The Wood- house Chain Co., is now filling an order for a cable of similar type, also for the revenue cutter service, of 1%4 in. diameter and 249 fathoms in length. The Wilgus Mfg. Co., corner Boyd and Wall streets, Los Angeles, Cal., have just put out little circulars de- scriptive of their oil burning machin- ery and appliances for burning oil.