Sect. VI.] Pneumatics. 51 



rate and successful investigation*. The theory of 

 millsy which he deduces from his experiments and 

 calculations, -is said to correspond with fact, to a 

 degree greatly beyond all other attempts f. 



The various improvements which the last cen- 

 tury produced in the construction of pumps, are 

 also worthy of notice. Since the doctrine of the 

 pressure of the atmosphere has been reduced to a 

 regular system, and the general laws of moving 

 fluids have been better understood, several advan- 

 tages in the formation and management of this 

 class of engines naturally followed. Those who 

 most distinguished themselves during the century, 

 by inventions, or laborious investigations, on this 

 subject, are Messrs. Hadley, Desaguliers, Haskins, 

 and Beighton, of Great Britain, Messrs. J. and D. 

 Bernoulli, and Wirtz, of Switzerland, and Messrs. 

 Pitot, Bossut, Belidor, de la Borda, d'Alembert, 

 de la Grange, and de Buat, of France. 



SECTION VT. 



PNEUMATICS. 



In Pneumatics, or that science which treats of 

 the mechanical properties of elastic fluids, modern 

 discoveries and improvements have been very nu- 



111. 



* See Trans. 'Amer. Philos;. Society, vol. 



t Mr. Waring \v^s an obscure character, • a native and resident 

 of Philadelphia. He belonged to the Society of Friends, and 

 taught a school in that city. Though little known, he was a 

 real philosopher. He died of the pestilence which raged in tltat 

 city in 1703. 



E2 



