XIV CONTENTS. 



source, the water is in motion, art. 190, page 180. On this principle large towns 

 and cities are supplied with water, art. 190, page 181. Edinburgh thus supplied, 

 ib. The principle of the proposition art. 183 generalized, art. 191, page 181. 

 Remark on ditto, ib. Two fluids of different densities, hut equal quantities, being 

 poured into a circular tube of uniform diameter, their positions determined when 

 in a state of equilibrium, art. 192, pages 181, 182, 183, and 184. The principle 

 assumed to be similar to that of Mr. Barclay's Hydrostatic Quadrant, art.193, page 

 184. Practical rule for ditto, ib. Example illustrative of ditto, art. 194, pages 

 184 and 185. The actual position of the fluids exhibited by a construction, art. 195, 

 pages 185 and 186. Mercury preferable to water for the tubes of philosophical 

 instruments, art. 196, page 186. Other fluids convenient for the purpose, art. 197, 

 page 186. The result of the investigation only applicable to mercury and water, 

 arts. 196 and 198, page 186. The same rendered general, art. 199, pages 186 and 

 187. The general equation deducible from the particular one, art. 199, page 187. 

 Practical rule for the general case, art. 200, pages 187 and 188. Example for 

 illustrating ditto, art. 201, page 188. The positions of the fluid different in the 

 two cases, art. 202, page 188. Inquiry into the changes produced on the general 

 formulae, under certain conditions, art. 202, page 189. Practical rule for reducing 

 the resulting equation, art. 203, page 189. Concluding remark, ib. 



CHAPTER VIII. 



OF THE PRESSURE OF NON-ELASTIC FLUIDS UPON DYKES, EM- 

 BANKMENTS, OR OTHER OBSTACLES WHICH CONFINE THE 

 FLUIDS, WHETHER THE OPPOSING MASS SLOPE, BE PERPENDI- 

 CULAR, OR CURVED, AND THE STRUCTURE ITSELF BE MASONRY, 

 OR OF LOOSE MATERIALS, HAVING THE SIDES ONLY FACED 

 WITH STONE. 



Introductory remarks, art. 204, page 190. The manner explained in which a 

 dyke, mound of earth, or any other obstacle, may yield to fluid pressure, art. 205, 

 page 191. Remarks on ditto, ib. General investigation, art. 206210, pages 

 191 197. Reasons adduced for not giving practical rules on this subject, art. 210, 

 page 197. Example for illustrating the reduction of the final equations, art. 211, 

 pages 197 and 198. The same illustrated when the effect produced by the vertical 

 pressure of the fluid is omitted, art. 212, pages 198 and 199. It is safer to calculate 

 by omitting the vertical pressure, art. 212, corol. page 199. The breadth at the 

 foundation determined when the slopes are equal, art. 213, page 199. Example 

 for illustrating ditto, art. 214, pages 199 and 200. The same determined when the 

 side on which the fluid presses is vertical, art. 215, page 200. More expensive to 

 erect a dyke of this form, than if both sides slope, art. 215, corol. page 201. The 

 same determined when the side of the dyke opposite to that on which the fluid 

 presses is vertical, art. 216, page 201. The stability in this case less than when 

 the vertical side is towards the water, art. 216, pages 201 and 202. 



Thickness of the dyke determined when both its sides are perpendicular to the 

 plane of the horizon, art. 217, page 202. Practical rule and example for this case, 

 art. 218, page 202. Thickness of the wall determined when its section is in the 



