A/A' WILLIAM SIEMENS, F.R.S. 



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recommend a form of engine working directly on the roll, and in 

 that respect he was obliged to differ from him. It was stated 

 that in working the steam cylinder with the connecting-rod 

 directly upon the axis of the roll, gearing was saved. That was 

 t nil-, but the gearing was saved at the expense of an enormous 

 strain on the craiik pin, an elaborate foundation, and a relatively 

 slow working of the piston. Admitting the advantage of sim- 

 plicity in connecting an engine directly to the working crank, 

 there were the drawbacks to which he had referred, which were in 

 fact drawbacks in regard to economical results, and also in regard 

 to the first cost of the engine. If the gearing was properly 

 constructed, and if the wheels and pinion were made of steel, 

 there was, in his opinion, nothing very objectionable in it. A 

 quick-working engine was more economical and more easily 

 repaired than a slow-working, long-stroke engine, and the pinion 

 and wheel were convenient pieces of mechanism to convert the 

 speed into the degree of reduction necessary to work a pair of 

 rolls : he therefore thought it would be better, on the whole, to 

 continue the system of having a quick-working reversing engine, 

 and to reduce the circular velocity by gearing. The author had 

 also dealt with the question of hydraulic arrangements for working 

 the pit both with the Bessemer converter and with the open- 

 hearth furnace, and in other parts of the machinery ; and the 

 question arose, what pressure would be most suitable for such a 

 purpose ? Sir William Armstrong was quoted as an authority for 

 fixing 700 Ibs. to the square inch as the proper pressure to be 

 used ; and for such purposes as had been named he believed it 

 was a very convenient working pressure. It would, however, be 

 wrong to assume that Sir William Armstrong advocated that 

 limited pressure under all circumstances. Dr. Siemens went to 

 him last year and asked whether he could make a cylinder 

 hydraulic ram of 3 feet diameter to work to 8,000 Ibs. pressure 

 per square inch. He was rather struck by the proposition, but he 

 did not say "No." Although his first idea was to use a coil for 

 the cylinder to give strength to it, a forged steel cylinder of 7-inch 

 wall thickness was eventually decided on. The accumulator and 

 other hydraulic arrangements were carried out by Sir William 

 Armstrong, but the hydraulic cylinder was furnished by Sir Joseph 

 Whitworth of compressed steel. He mentioned this case to show 



