Perkins" 1 Steam Engine. 49 



tioned. The mechanical difficulties against which he has 

 had to contend, in controlling and applying the tremendous 

 power of high pressure steam, have not only absorbed much 

 more time than he anticipated, but have also demanded a 

 greater outlay of money. 



The newly constructed engine, to which we have adverted 

 in our preceding number, has been at work for some days, 

 apparently very much to the satisfaction of the few engineers 

 who have seen it. We have been repeatedly present during 

 its performance, and studiously considered its operations, in 

 which we have not been able to detect any fallacy. As, how- 

 ever, we do not mean, at present, to pledge ourselves as to 

 any definite power which the engine is capable of exerting, 

 we shall simply state the manner in which a certain power 

 has been demonstrated in our presence, leaving our readers 

 to draw their own conclusions, from the facts set forth. 



The fly-wheel is eight feet in diameter, and the steam, 

 working, as Ave are informed, at a pressure of twenty-seven 

 atmospheres, caused the piston to perform sixty strokes per 

 minute. The periphery of the fly-wheel being pressed upon 

 by # a loaded lever, (called in mechanics,) of the second order. 

 The power exerted by the engine at that time, may be known 

 by calculating the amount of force, or friction, acting upon 

 the fly-wheel. 



The lever was a wooden bar, about four inches square, 

 bearing upon the periphery of the wheel at the top. The 

 shorter arm of the lever, or distance from the fulcrum to the 

 impinging point, where the pressure acted upon the wheel, 

 was fourteen inches ; from thence to the end, that is, the lon- 

 ger arm of the lever was ninety inches. To the extremity 

 of the lever was suspended a weight, making with that of 

 the bar, rather more than one hundred and fifty pounds. 

 From this may be known the actual force overcome, or work 

 done by the engine at that time. By the addition of fifty 

 pounds weight to the end of the lever, the engine labored, 

 but still worked steadily ; by the removal of part of the 

 weight, the speed of the engine became nearly doubled.. 



The steam, it was said, acted under a pressure of twenty- 

 seven atmospheres, but Mr. P. states that he usually employs 

 a pressure of fifty-six atmospheres, and that the consump- 

 tion of coal per hour, is about half a bushel. 



Under this pressure of about 800 lbs. upon the inch, the 

 steam is admitted into the working cylinder, and when the 



Vol. XIIL— No. 1. 7 



