and Orography of the Earttis Surface. 3 



be too great, if other calculations conduct Rozet to believe 

 that this value is 1000 times smaller than the volume of the 

 compact parts of the globe (Traite de Geologie, 1835, p. 15). 

 The volume of the whole spheroid would be, according to 

 Breislak, 1,230,320,000 cubic leagues ; according to Daubuis- 

 son, 1,079,235,800 cubic myriameters (Traite de Geognosie, 

 1819, vol. i., p. 25) ; and according to Reviere, 1,082,634,000. 

 K. M. Beudant allows the quantity of the water on the 

 globe under two millions of cubic myriameters. 



"When we have once the true value of the sea water and its 

 basin, we can logically conclude from 

 this the value of the dry land. But 

 here is the place to remark that the 

 highest chains are placed always 

 only upon the greatest protuberances or vaults of the earth's 

 surface, which is quite natural ; but together give an indica- 

 tion of the maxima and minima values of the elevations upon 

 the whole globe, as well as in each country. In other words, 

 if we find heights from 24,000 to 27,000 feet in South America 

 and the Himalaya, or similar cavities in the Austral seas, we 

 must not believe that there exist in the earth such a force of 

 elevation or subsidence ; but that only the last elevations 

 have taken place upon a soil already elevated upon a vault 

 of the earth, and that in the same way the subsidence has 

 happened on parts already subsided. It is yet possible that 

 a chain may be wholly upheaven in later times ; but our 

 Alps in Europe shew us that we can hardly admit of a 

 single elevation of 8000 feet at once, for all the summits 

 and pinnacles which reach above 10,000 feet did gain this 

 height only by the inclination of their composing beds. On 

 the other hand, a yet unknown physical law has established 

 an intimate relation between the value of the greatest eleva- 

 tions or upheavings, or highest mountains of each continent 

 and their relative individual extent. A kind of scale of this 

 description is furnished by the Himalaya, the Chimborazo, 

 and Mont Blanc, three continents of unequal greatness. 



The same relation is to be observed among the cavities of 

 the earth, for the greatest sea depths are in the Austral seas, 

 where the extent of dry land is to that of water as 1 : 16. 



A 2 



