VIII CONTENTS. 



CHAPTER II. 



OF THE PRESSURE OF NON-ELASTIC FLUIDS UPON PHYSICAL 

 LINES, RECTANGULAR PARALLELOGRAMS CONSIDERED AS 

 INDEPENDENT PLANES IMMERSED IN THE FLUIDS, AND 

 UPON THE SIDES AND BOTTOMS OF CUBICAL VESSELS, 

 WITH THE LIMIT TO THE REQUISITE THICKNESS OF FLOOD- 

 GATES. 



Physical line when obliquely immersed, pressure on determined, art. 22, pages 

 10 and 11. Practical rule for calculating ditto, art. 23, page 11. Example to 

 illustrate ditto, art. 24, pages 11 and 12. The same determined for a line when 

 perpendicularly immersed, art. 25, page 12. The same determined for a line 

 obliquely immersed, when the upper extremity is not in contact with the surface 

 of the fluid, art. 26, pages 12 and 13. Pressure determined when the perpendicular 

 depth of the upper extremity is given, art. 26, equation (5), page 14. Practical 

 rule for ditto, art. 28, No. 1, page 14. The same determined v hen the perpendi- 

 cular depth of the lower extremity is given, art. 27, equation (6), page 14. Prac- 

 tical rule for ditto, art. 28, No. 2, page 14. Example to illustrate ditto, art. 29, 

 pages 14 and 15. The pressure determined when the line is perpendicularly im- 

 mersed, art. 30, page 15. Two physical lines obliquely immersed, with their upper 

 extremities in contact with the surface of the fluid, to compare the pressures upon 

 them, under any angle of inclination, art. 31, pages 15 and 16. The lines being 

 unequally inclined, the pressures directly as the squares of the lengths and sines of 

 inclination, art. 31, inf. 1, page 16. When the lines are equally inclined, the pres- 

 sures are directly as the squares of the lengths, art. 31, inf. 2, page 16. The lines 

 being similarly situated the pressures can be compared, art. 31, inf. 3, page 16. 

 The lines being differently situated in the fluid, the pressure is determined, art. 32, 

 page 17. Right angled parallelogram obliquely immersed, pressure determined, 

 art. 33, equation (7), page 1 9. Practical rule for ditto, art. 34, No. 1, page 19. 

 Plane perpendicularly immersed, the pressure determined, art. 33, equation (8), 

 page 19. Practical rule for ditto, art. 34, No. 2, page 19. Example for illustration 

 of the inclined case, art. 35, pages 19 and 20. Example for illustrating the per- 

 pendicular case, art. 36, page 20. The parallelogram obliquely immersed and 

 the longer side coincident with the surface of the fluid, pressure determined, art. 37, 

 equation (9), page 20. Perpendicularly immersed, pressure determined, art. 37, 

 equation (10), page 20. Pressures compared, art. 37,corols. 1, 2, and 3, page 21. 

 Right angled parallelogram immersed as before and bisected by its diagonal, the 

 pressures on the triangles determined and compared, art. 38 and 39, pages 21, 22, 

 23, and 24. Practical rules for the pressures, art. 40, page 25. Example for 

 illustration, art. 41, page 25. Centre of gravity of a right angled triangle deter- 

 mined, art. 42, pages 26 and 27. Rectangular parallelogram bisected by a line 

 parallel to the horizon, the pressure on the two parts determined and compared, art. 

 43, pages 27, 28, and 29. Practical rules, art. 44, Nos. land 2, page 29. Examples 

 for illustration, art. 45, pages 29 and 30. Rectangular parallelogram so divided by 

 a line parallel to the horizon, that the pressures on the two parts are equal, art. 46, 

 pages 30, 31, and 32. The same effected geometrically, art. 47, page 32. Practical 

 rule for the calculation of ditto, art. 48, page 33. Example to illustrate ditto, art. 



