110 Discourse delivered hy Baron Humboldt to the 



not many years ago covered it, previous to the flames which 

 were perceived by navigators at a distance. 



To solve in a satisfactory manner the great problems relative 

 to the depression, which is perhaps variable, of the level of the 

 waters, and of that of the continental basin of the Caspian Sea, 

 it were desirable that there should be traced a soundings line 

 around this basin, in the plains of Sarepta, Ouralsk, and Oren- 

 burg, by uniting the points which are precisely at the level of 

 the Baltic and Black Seas ; that it should be determined by 

 marks placed on the coasts all round the Caspian Sea (like the 

 marks placed nearly a century ago on the coasts of Sweden, by 

 the directions of the Stockholm Academy), whether there be a 

 general or partial, a continuous or periodical, fall of the waters, 

 or whether (as the great geologist M. Leopold de Buch sup- 

 poses in respect to Scandinavia) a part of the neighbouring land 

 is elevated or depressed by volcanic causes acting at immense 

 depths in the interior of the globe. The mountainous isthmus 

 of Caucasus, partly composed of trachyte and other rocks, 

 which undoubtedly owe their origin to volcanic fires, margins 

 the Caspian Sea to the west, while it is surrounded to ihe east 

 by tertiary and secondary formations, which extend towards 

 those countries of ancient celebrity, for the knowledge of which 

 Europe is indebted to the important work of Baron Meyen- 

 dorf. 



In these general views, which 1 submit to your enlightened 

 consideration, I have attempted to point out some of the advan- 

 tages which the physical history of the globe might derive from 

 the position and extent of this empire. I have exposed the 

 views which vividly presented themselves to me, in sight of the 

 regions I'rom which I have just returned. It has appeared to 

 me more suitable to render a public testimony of approbation to 

 those who, under the auspices of the government, have pursued 

 the same career as myself, and to direct the attention to what 

 remains to be done for the advancement of science, and for the 

 glory of your country, than to speak of my own efforts, and 

 compress within a narrow compass the results of observations 

 which have still to be compared with the great mass of partial 

 data which you have collected. 



I have alluded in this discourse to the extent of country 



