HEIGHTS FROM THE LEVEL OP THE SEA. 383 



pies of mechanics and hydrostatics to these purposes, the peculiar 

 circumstances of the case may indicate to an ingenious artist a mode 

 of performing the required work in an effectual and economical 

 manner. We may find a good example of such an arrangement, in 

 the account given, by Mr. Smeaton, of the method which he adopt- 

 ed for the improvement of the port of Ramsgate, and which indeed 

 resembles some that had been before employed in similiar cases: by 

 forming a large excavation, which is furnished with flood-gates, and 

 is constantly filled at high water, he has procured a number of 

 artificial torrents, which escape through the sluices, and become 

 powerful agents for carrying away the matter deposited by the sea, 

 and tending to impede the navigation of the harbour. 



^Communications to the Board of Agriculture. ( Trans, of 

 the Society of Arts, fyc. Young 1 s Nat. Phil. Editor. 



SECTION XIII. 



Table of Heights, in English feet> from the level of the Sea. 



THIS valuable comparative estimate we take as laid down by 

 Dr. Young, from the measurements of Deluc, Shuckburgh, Roy, 

 Bougue'r, and others. 



The Caspian Sea, lower by 306 one-third above low water mark at 



The Thames, at Hamptou, Roy 14 Isleworth. 



The Tiber at Rome 33 The pagoda in Kew gardens 



The Seine at Paris, mean height 36 from the ground 116 



The Thames, at Buckingham The west end of the Tarpeian 



Stairs fifteen feet and a half rock I5F 



below the pavement in the The Palatine hill 165 



left hand arcade 43 The Claudian aqueduct, bot- 



By barometrical comparison with the torn of the canal 208 



Seine and the Mediterranean, but The Janiculum 293 



tliis height is probably too great. The cross at St. Paul's, from 



Roy supposes the low water of the the ground 340 



spring tides at Isleworth to be only St. Peter's,summit of thecross 53 

 one foot above the mean surface of From the ground 471 



the ocean. He allows seven feet Arthur's seat, from Leith pier 



for the difference of the low water head 803 



at the Nore and at Isleworth, taking Lake of Geneva 1230 



18 feet for the height of the spring Its greatest depth 393 



tide, adds one-third of this for the Mount Vesuvius, base of the 



mean height of the sea. At Hatnp- cone 1 2021 



ton the Thames is thirteen feet and Saddleback ,. 3048 



