4s Mechanicdl Philosophy, 



an additional and most powerful argument in sup-* 

 port of the Newtoiiian system. 



The construction of Aqueducts has been ren- 

 dered, by the labours of modern philosophers, more 

 simple, easy, and precise. And, in consequence 

 of these improvements, they have, within the last 

 century, greatly increased in number. For the 

 valuable experiments and discoveries which have 

 been made on this subject, we are principally in- 

 debted to the great hydraulic philosophers on the 

 continent of Europe, whose names were before 

 mentioned. To those names may be added the 

 distinguished experimenters and observers, on the 

 same subject, Desaguliers, Belidor, De Par- 

 ciEux, and Perronet, who successively laboured 

 to deduce a system of doctrines from the nume- 

 rous facts before them; and whose very mistakes 

 contributed to elucidate this obscure branch of 

 science, which, however, is yet far from being 

 fully understood. 



Very great improvements have also been made, 

 during the period in question, in the principles and 

 construction of Water-Mills. The proper mode 

 of adjusting forces, and calculating velocitiea, in 

 this, as well as in almost every other branch of hy- 

 draulics, has long been considered among the most 

 difficult problems in philosophy .^ — Mr, Desagu- 

 liers, early in the century, made a number of ex- 

 periments on mills, and suggested some important 

 improvements in their principles and construction. 

 About the same time, M. Belidor, of France, 

 M. Bernoulli, and Mr. Emmerson, of Britain, 

 employed their great learning and talents on this 

 subject, and made considerable progress in its il- 

 lustration. These were followed by Mr. Lam- 

 bert, of BerHn, Mr, Elvius, of Sweden, Pro- 

 fessor Karstner, of Gottingen, M. DeParcieux, 

 before mentioned^ and Messrs. Smeaton, B^r- 



