7*2 HISTORY OF MECHANICS. 



in France, have laboured at the same task, as have 

 Coulomb and Prony, Girard and Poncelet. Eytel- 

 wein's German treatise (Hydraulik), contains an ac- 

 count of what others and himself have done. Many 

 of these trains of experiments, both in France and 

 Italy, were made at the expense of governments, 

 and on a very magnificent scale. In England less 

 was done in this way during the last century, than 

 in most other countries. The Philosophical Transac- 

 tions, for instance, scarcely contain a single paper 

 on this subject founded on experimental investiga- 

 tions 4 . Dr. Thomas Young, who was at the head of 

 his countrymen in so many branches of science, was 

 one of the first to call back attention to this : and 

 Mr. Rennie and others have recently made valuable 

 experiments. In many of the questions now spoken 

 of, the accordance which engineers are able to 

 obtain, between their calculated and observed re- 

 sults, is very great : but these calculations are per- 

 formed by means of empirical formulae, which do 

 not connect the facts with their causes, and still 

 leave a wide space to be traversed, in order to 

 complete the science. 



In the mean time, all the other portions of 

 Mechanics were reduced to general laws, and ana- 

 lytical processes ; and means were found of includ- 

 ing Hydrodynamics, notwithstanding the difficulties 

 which attend its special problems, in this common 

 improvement of form. This progress we must now 

 relate (c). 



4 Rennie, Report to Brit. Assoc. 



