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May, 1909 ply in fresh water, and, second, ow- ing to the shortness of 'the season and brief stay in port, the desiga must: be simple and capable' of: as easy adjustment as possible. Owing to the distance of th: lakes from the coast, the early designers. were not influenced particularly by 'the ordi- nary marine practice, <ni this, con- bined with the necessity of decreasin the cost of manufacture, has doubtless led to the adoption of some of the principal details in "design." It is not by any means: clear what is meant by "stereotyped marine en- gine," but it may be assumed to. refer to sea-going practice as contrasted It wil', we think, be conceded, that even sea-going prac- with lake practice. tice is very far from being uniform and exhibits a wide rangé 01 variety in design--in 'fact it would be rathe- nearer the mark to cs.aracterize th» lake: design as stereotyped. But after all, what are the: "orths- dox" features to which' the professor Firstly, these refers? ships are de- signed for fresh water, which, we take it, is merely. incidental. This, however, makes 'a condenser type has therefore never been displaced as at unnecessary and the j<ct sea. This, then; is not a departure at all, rather the contrary, since. it was only about 50 years since that the surface condenser succeeded the jet at sea, It is in the second cause of dii- ference, however, that> we cannot clearly grasp 'the professor's meari- ing. He surely does not mean: to say that. simplicity and eas: of adjust- ment are not at all times valuable. Every ,designer aims. to accomplish those very things according to. his own ideas which are, more often than not, merely those of others, precedent or contemporary. The lake designers and builders are, therefore, indebted to the professor for a very graceful compliment, and it is not in any way minimized by the further reference to the necessity of reducing cost of construction--another poiit which n) builder of our acquaintance ever Over- looks. That the engines have not suffered as a result of these condi- (HE Marine REVIEW tions is amply proved by their ser- vice, in which a breakdown is almost unknown, although p'ston speeds on the lakes are materially higher than is, Usual at. Sea : There are, practically speaking, only two essential points of difference be- tween lake and sea practice in design. One of these is. the emp'oyment of shafts in the the high We have had occasion to investigate rock prevailing .type to. drive valve. pressure this feature heretofore, and although employed in some hundreds of en- gines of all sizes we dd not: learn 0: a single'. instance .of, failure, mor ,15 there any good reason why there should be. The duty is very. light in- deed; the valves are, without excep- tion of the piston type and the. iner- tia strains are very liw. There are thousands of locomotives employing the same transmizsion under condi- tions a hundred fold wor.e. -That its use results in shortening up the engin: is ample justification. | The second point is in the arrange- ment of crosshead, There :are two standard forms of crosshead in seago- ing practice; in one the crosshead is forged with the piston rod and em- braces the top end bearing brasses, the pin being shrunk into the forked Of all designs this is the most miserable; end of the connecting rod. adjustment is difficult and extremely tedious and generally can be. made only at the bottom of the stroke be- - cause of the difficulty of getting at the inside bolt, and a lead cannot be taken without jacking the crosshead up to take down the bottom brass. The piston rod has to 'come out the lower end of the cylinder and 'when, as sometimes happens, a rod is bent, disconnection is almost impossible. The second type, in which the cross- head carries gudgeons which are taken by boxes carried on the horns of the top end, while very much better than the first, is more "expensive, and on account of unequal wear is apt to throw the crank end of the rod hard on to one crank cheek or another, and frequently results in' heat § Or noisy working. 111 The lake design with its readily re- movable pin and straight line bearing and quick adjustment has much' to recommend it. We have seen slack taken up in one of these without stopping the engine and we have seen the crosshead blocked and the' pin out on the grating and the rod swung clear in five minutes. These are fea- tures of real value'and aside from the fact that it increases the height of engine slightly there is no good rea- son why it is not perfectly suitable for any service. These are the only points in which any greater: difference is to be found than in different, en- gines at sea, and there are no engines anywhere their work more economically than those in the bulk freighters of the great lakes. doing - AMERICAN SOCIETY OF ME- CHANICAL ENGINEERS. The spring meeting of the American. Society of Mechanical Engineers was held at Washington, D. C., on Wednes- day, Thursday and Friday, May 5, 6 and 7. Professional sessions were held in the forenoon each day, the after- noong and evenings being devoted to social and entertainment features, At the Thursday morning session a paper by C. Lee Straub, of New York, on "Marine Producer Gas Power" was presented, which we reproduce 'in full in this issue. It is much to be regretted that time for full discussion of this paper was not available, a number of members signifying their wish to partic- ipate. Following Mr. Straub, Mr. Henry Penton was invited to describe in detail the commercial and operating conditions of marine service, which he did, more particularly with reference to the type ? Mr. Penton described the operating condi- of ship selected for illustration. tions with steam and the various prob- lems to be considered in substituting gas power, the kinds and grades of fuel available, and showing that it was es- sentially a bituminous coal proposition. The basis upon which the extinction of cost was calculated was also shown. He drew attention to the fact that the load factor of the marine engine is, i good weather, ideal and very different from the conditions existing in most