MECHANICS OF FLUIDS 



CHAPTER I. 



DEFINITIONS AND OBVIOUS PROPERTIES OF WATERY FLUIDS, WITH 

 THE PRELIMINARY ELEMENTARY PRINCIPLES OF HYDRODYNA- 

 MICS, FOR ESTIMATING THE PRESSURE OF INCOMPRESSIBLE 

 FLUIDS. 



1 . THE phenomena of Hydrodynamics are those truths which explain 

 the peculiarities of equilibrium and motion among- fluid bodies, espe- 

 cially those that are heavy and liquid. As that branch of natural phi- 

 losophy which points out and explains the properties and affections of 

 fluids at rest, it comprehends the doctrine of pressure, specific gravity, 

 equilibrium, together with the circumstances attending the positions, 

 equilibrium, and stability of floating bodies, the phenomena of cohe- 

 sion and capillary attraction. And as that other branch of natural 

 philosophy which points out and explains the motions of such fluids as 

 have weight and are liquids, it investigates the means by which such 

 motions are produced, the laws by which they are regulated, the dis- 

 charge of fluids through orifices of various dimensions, forms, and 

 positions, the motion of fluids in pipes, rivers, and canals, and the 

 force or effect they exert against themselves, or against solid bodies 

 which may oppose them. Hydrodynamics, therefore, from Greek 

 words signifying water and force, comprehend the entire science of 

 watery fluids, whether in a state of rest or of motion ; and this 

 science, practically considered, enables us to investigate and apply 

 a fruitful source of maxims and principles, upon which depend the 

 construction and efficiency of engines and machines employed in the 

 arts, manufactures, and domestic concerns of society, together with 

 that extensive class of mechanical combinations displayed in the more 

 delicate and important operations of HYDRAULIC ARCHITECTURE. 



VOL. i. B * 



