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VII. 



ON THE MAXIMUM OF MECHANIC 

 POWERS, AND THE EFFECTS OF MA- 

 CHINES WHEN IN MOTION. 



By Lieutenant William Lambtok, 

 Of His Majejlfs 33^ Regiment of Foot* 



MOST mathematicians, in treating on the fcience 

 of mechanics, have drawn their conclufions 

 from confidering the weight and power in a ftate of 

 equilibrium, and have deduced their proportions from 

 their refpe6live diftances of each from the center of 

 motion ; or from what the velocities would be, fup- 

 pofmg them to be put in a moving ftate. But in the 

 adVual application of any machine, whether fimple or 

 compound, we fliall find that when it is put in motion 

 by the fuperior force of the power, there will be a 

 certain ratio between the weight and power, fo that 

 in any given time the effeft may be the grcateft poffible. 

 The various and moft ufeful cafes which relate to this 

 fubjeft are comprifed in the following problems, and 

 as it is my intention to determine the precife efie6ts 

 of fuch fK)wers as are of the moft general ufe in the 

 conftruftion of machines, fuch as the lever, the wheel, 

 and axle, &;c. and where the power applied to raife the 

 weight, afts by the force of gravity j it will be ncceflary 

 to take into confideration the effe61s of their own 

 mafles, and therefore fome general propofitions muft 

 be premifed relative to the centers of percuffion and 

 gyration of the refpe6live moving powers ; and tp 

 compare the mafs collected into the center of per- 

 cufl'ion or gyration of a beam or folid wheel, to that 

 power, which a6ling at the extremity would give th^ 

 fame angular velocity. 



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