Relations of the Physical and Chemical Forces. 63 



of Archimedes, " Give me a place to stand upon and I 

 will move the world," possesses a far greater significance 

 in the infinite uses to which the lever is applied in our 

 complex civilisation, than in the hyperbolic enunciation 

 of the principle of the indefinite quantitativeness of the 

 mechanical forces recorded of the Syracusan philosopher. 



(II.) That definite quantities of mechanical force will 

 generate definite quantities of heat has been tacitly recog- 

 nised for thousands of years by native races throughout 

 the world in the various methods of producing fire by the 

 friction of two pieces of wood. One of these methods, 

 shown in Fig. 2, is taken from a prehistoric Mexican 

 picture-writing, wherein a native is seen twirling a drill, 

 while the fire comes out from the hole where the point 

 revolves.* 



Fig. 2. 



Just as the smallest weight or force will balance and 

 overcome the greatest, so through the action of the lever 

 an indefinitely small amount of mechanical force will 

 induce an indefinitely large amount of heat. This 

 proposition finds abundant illustration in the friction 

 dynamometer ; in brakes as applied to carriages and 



* Lord Kingsborough's Antiquities of Mexico. Vol. II. Bodleian 

 Laud MS. 



Tylor's Researches into the Early History 0/ Mankind, p. 242. 



