"44 Mechanical Philosophy. [Chap. I. 



toni, of 'Italy, and Messrs. d'Arcy and le Roy, 

 of France, are entitled to particular distinction*. 

 I^cside these, many experiments have been made, 

 and valuable ideas suggested, respecting motion 

 in resisting mediums, by Gravesande, by J. Ber- 

 noulli, by Euler, by Simpson, by M. Bouguer; 

 and by AI. Condorcet, abbe Bossut, chevaliers 

 Buat and Borda, and other members of the Royal 

 Academy of Sciences at Paris. And although this 

 part of mechanical philosophy can scarcely be said 

 yet to have received satisfactory elucidation ; still 

 much has been done toward the attainment of this 

 object by the mathematicians and artists of the 

 last age ; and especially by those of France, who, 

 in the various parts of science immediately subser- 

 vient to the business of the Engineer, have cer- 

 tainly, in modern times, exceeded all the rest of 

 the world. 



The discoveries and improvements made, in the 

 course of the last century, with respect to the con- 

 struction and motion oi pendulums, are neither few 

 nor unimportant. For the purpose of counteract- 

 ing the effects produced in the dimensions of the 

 pendulum by heat and cold, from which disorder 

 and error necessarily arise, the contrivances of in- 

 genious men have been numerous and successful. 

 For the purpose, also, of regulating the curve m 

 which this body shall move, various devices and 

 calculations have been adopted. The principal of 

 these improvements are, the Mercurial Pendulum, 

 invented by George Graham ; the Gridiron Pen- 

 dulum ; that formed with a rod of baked and var- 



* Uuiion's M(it/u-matic(d Dictionari/. 



