THE AEALO-CASPIAN BASIN. 125 



Aran and Sjr, and tlie varying form and area of the water-surface of which 

 Lake Aral and the Caspian Sea are the principal relics, would require more 

 space than can here be allowed. The main point in connection with the 

 subject at present before us is this : that the area covered by water in this 

 part of Asia Avas once vastly larger than it now is. It is also true that this 

 diminution has been effected — to a considerable extent at least — within 

 historic times, and there is little doubt that it is still going on. 



Humboldt seems to have been the first physical geographer to fully 

 appreciate the interest attaching to the question of the former extension 

 of the two inland seas, the Aral and the Caspian, and tiioir connection with 

 the Polar Ocean. By his citations of the ancient authors who have written 

 on this subject, he has made it easy for more modern investigators to follow 

 the various contradictory opinions put on record by various writers, from 

 the time of Herodotus down to the beginning of the sixteenth centux'y.* 

 It was at Humboldt's request that the necessary hypsometrical determina- 

 tions were made, under the direction of the St. Petersburg Academy, to 

 determine the precise difference of level between the Caspian and the Black 

 Seas. The same eminent authority was also the first to clearly perceive 

 that violent catastrophes or orographic causes need not be called upon to 

 account for the desiccation of this region, but that the phenomenon was 

 purely a climatic one. He says : " The desiccation which is unquestionably 

 going on in the basin of the Aral Sea, and the changes which are to be 

 observed in that long file of lakes which mark the traces of a chainiel [sil- 

 lon] from the Aksakal Bai'bi to the pools [mares] of the Baraba steppe (the 

 remains of the Bitter Sea of the Chinese Annals), are in no way dependent 

 on any violent revolution in the order of nature. They are simply the 

 effects of the want of equilibrium between evaporation and the volume 

 of water brought in by affluent streams and by atmospheric precipitation. 

 They are quite of another character from the cataclysms of Fo-hi and Yao, 

 which are supposed to have happened thirty-five and twenty-four centuries 

 before the Christian era."t 



A more recent investigator in the same field is Major Herbert Wood, of 

 the Royal Engineers, who devotes considerable space in his work entitled 

 "The Shores of Lake Aral,"t as also in an article communicated to the 



* See Asie Centrale, Paris, 1S43 ; Vol. II. p. 156. 

 t 1. c, Vol. II. p. 142. 



t London, 1876. See especially Chapter X., " The Aralo-Caspian Sea," and Chapter XI., "The Caspian of 

 History." 



