I* 



CONTENTS. 



CHAPTER I. 



DEFINITIONS AND OBVIOUS PROPERTIES OF WATERY FLUIDS, 

 WITH THE PRELIMINARY ELEMENTARY PRINCIPLES OF 

 HYDRODYNAMICS, FOR ESTIMATING THE PRESSURE OF 

 INCOMPRESSIBLE FLUIDS. 



THE subject introduced, art. 1, page 1. Fluid what, art. 2, page 2. Fluid presses 

 equally in all directions, art. 3, page 2. Lateral pressure equal to the perpendicular 

 pressure, art. 3, page 2. Fluid equally pressed in all directions, art. 4, page 2. 

 Fluid pressure against containing surface, perpendicular to that surface, art. 5, 

 page 2. Fluid, surface of horizontal, or perpendicular to the direction of gravity, 

 art. 6, page 2. The common surface of two fluids which do not mix, parallel to the 

 horizon, art. 7, page 2. The surfaces of fluids continue horizontal when subjected 

 to the pressure of the atmosphere, art. 7, page 2. Fluid particles at the same depth 

 equally pressed, art. 8, page 2. Fluid pressure varies as the perpendicular depth, 

 art. 9, page 2. Fluid pressure measured by the weight of a column whose base is 

 the surface pressed, and altitude the perpendicular depth of the centre of gravity, 

 art. 10, page 3. Fluid pressure identified with a property of the centre of gravity, 

 art. 11, 12, and 13, pages 3 to 7. Fluid pressure assignable, art. 13, page 8, corol. 

 Pressure of different fluids on different plane surfaces immersed in them, as the 

 areas of the planes, the perpendicular depths of the centres of gravity, and the 

 specific gravities of the fluids, art. 14, page 8. Pressure of the same fluid on dif- 

 ferent plane surfaces immersed in it, as the areas of the planes and the perpendicular 

 depths of the centres of gravity, art. 15, page 8. Plane parallel to fluid's surface, 

 pressure on ditto varies as the perpendicular depth, art. 16, page 8. Plane surface 

 inclined to the surface of the fluid, pressure on ditto varies as the perpendicular 

 depth of its centre of gravity, art. 17, page 8. Planes of equal areas, whose centres 

 of gravity are at the same perpendicular depth, sustain equal pressures, whatever 

 may be their form and position, art. 18, page 8. The centre of gravity remaining 

 fixed, the pressure upon a revolving plane is the same at all points of the revolu- 

 tion, art. 19, pages 8 and 9. A plane surface being immersed in two fluids of 

 different densities, if the pressures are equal, the depths of the centres of gravity 

 vary inversely as the densities of the fluids, art. 20, page 9. The same principle 

 demonstrated, art. 21, page 9. 



