72 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. 



