MECHANICS AND USEFUL AKTS. 29 



new light on the subject, from which it appears that the 'red tape- 

 ism' is all-powerful in the Naval Department of President Lincoln's 

 administration. To a final suggestion that the question should be 

 fairlv put to the test on the river Potomac, in presence of judge and 

 jury, the defendants turned a deaf ear. The experiment was made, 

 notwithstanding, on board the steamship Gollyer; when it turned 

 out that with GOO pounds of coal an hour, she could run at the rate 

 of 27 revolutions a minute with expansion, and that but 20 a minute 

 could be got without expansion, and with 700 pounds an hour. This 

 evidence was deemed so conclusive, that a verdict was at once given 

 for the complainant. It is not difficult to imagine what English en- 

 gineers will think of all this. Mr. Isherwood's evidence is sc opposed 

 to all theory and all practice, that, did he hold a different position, 

 or were he less talented, his word would simply be passed over with a 

 smile, or perchance, a hearty laugh. The value of expansion, prop- 

 erly carried out, is pretty well understood among us ; and it would 

 be unfair to deny that many American engineers attach a proper im- 

 portance to the principle as well. When the Chief Engineer of a 

 great navy, gives utterance to sentiments and opinions so widely op- 

 posed to those held by other -experts, a natural curiosity is experi- 

 enced to know where he got them. We will try and enlighten our 

 readers. 



In the early part of the year 18GO, the United States Navy De- 

 partment, in the plenitude of its wisdom, deemed it right that 

 certain 'experiments should be made to determine the relative econ- 

 omy of using steam with different measures of expansion. Not 

 content with the evidence afforded them by the practical operations 

 of the Cornish pumping engine, the locomotives on the New York 

 railroads, or the marine engines in use on the rivers and seas of the 

 Western Continent, the gentlemen of the Department resolved on 

 instituting thorough experimental research into the whole subject ; and 

 with this object in view they appointed Chief Engineer Isherwood 

 and three other engineers, as a committee, to make the experiments. 

 As very valuable results were anticipated, it is natural to suppose, 

 that more than one engine was reported on : that the best engines in 

 the navy would be selected, and tlfe necessary data derived from the 

 performance of the engines tried, at sea, under the ordinary condi- 

 tions of working, first, and subsequently, under such extraordinary 

 conditions as seem best adapted to the attainment of the end in view. 

 Such a conclusion is not more natural than erroneous. But one steam- 

 er, the Michigan, was selected. At the time of the experiments, 

 February 1860, she was out of commission, frozen up in Lake Erie ; 

 the hull had been recently repaired, and the old boilers replaced 

 with new ones, constructed on Martin's patent, with vertical Avater 

 tubes, instead of horizontal flues over the furnaces. The engines 

 were two in number, of a form not much known in England : the 

 cylinders, 06 inches in diameter, and having a stroke of eight feet 

 lying in an inclined position and at an angle of 28 degrees with 

 the keel. Not content with confining the experiment to the narrow 

 basis afforded by a single steamboat, Mr. Isherwood and his col- 

 leagues still further restricted it, by retaining only one of the two 

 cylinders in use : the other being uncoupled from the crank-shaft 

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