Histonj of the Science of Hydraulics. 195 



could be increased. His work upon the discharge of fluids 

 through orifices was published in 1718. Varignon in 1725 

 published his work on hydraulics in which lie reduced the 

 parabolic theory of rivers to algebraic formulae. 



M, Pitot, between the years 1730 and 1738, made a series 

 of experiments upon the velocities at different depths by 

 means of the tube which bears his name. These experiments 

 proved the fallacy of the parabolic theory of flowing water. 

 In 1732, were published the results of the experiments by 

 Couplet upon the discharge of water-pipes at Versailles. At 

 the same time appeared the works of many Italian writers, 

 such as Gracdi, Manfredi, Zendrini, Frisi, Zanotti, Gennette. 

 In 1798 was published the work of Daniel Bernouilli, who 

 applied the principle of living force to the motion of fluids, 

 which forms one of the schools of hydraulics. 



Between the years 1742 and 1752 appeared the works of 

 John Bernouilli and d'Alembert, upon the theoretical science 

 of hydraulics. Valuable theoretical papers upon the motioa 

 of fluids by the celebrated engineer, Lecchi, and by Euler, 

 appeared between 1765 and 1771. Professor Michelotti of 

 Turin, and the Abbe Bossuet of Paris, first established it as a 

 fundamental principle, that formulae must be deduced from 

 experiment and not from theory. The former conducted an 

 extensive series of experiments under the patronage of the 

 king of Sardinia, the results of which were published in 1771:; 

 the latter conducted a series of experiments under the patron- 

 age of the French government, the results of which were pub- 

 lished from 1771 to 1778. Both of these furnish important 

 data, particularly the latter, and have been of great value 

 to succeeding writers in deducing constants and testing the 

 accuracy of formulae. We consider that the origin of the 

 modern school of hydraulics is due to the last two named 

 authors. The works of the earlier writers are now of but 

 little importance to the practical engineer. 



In 1775, M. Chezy, an eminent French engineer, deduced 



