118 Baron Alexander von Humboldt on the Physiognomy 



General Andreossy, by the small bitter lakes in the Isthmus 

 of Suez, by the Lake of Tiberias, and, above all, by the Dead 

 Sea.* The level of the Avaters of the two last mentioned 

 lakes is Q%Q and 1312 English feet lower than the surface of 

 the Mediterranean Sea. If we could suddenly remove the 

 alluvial matter which covers the sti'ata of rock in so many 

 level parts of the earth, it would become manifest how many 

 portions of the solid surface of the globe at present occupy 

 a lower level than the surface of the ocean. The periodical, 

 although irregularly alternating, rise and fall of the Caspian 

 Sea, of which I have myself seen distinct traces in the north- 

 ern portion of that basin, appears to provef (as is also shewn 



* Humboldt, Asie Gaiiralc, t. 2, pp. 319-324 ; t. 3, pp. 549-551. Tlio 

 depression of the Dead Sea has been gradually ascertained through 

 means of the barometrical measurements of Count Bertou, the much 

 more careful measurements of Russegger, and the trigonometrical 

 measurement of Lieutenant Symonds of the English navj'. The last 

 mentioned observer, in a letter addressed by Mr Alderson to the Geo- 

 graphical Society of London, and communicated to me by my friend 

 Captain Washington, has stated that the difference of level of the surface 

 of the Dead Sea and of the highest house in JatTa is 1605 English feet. 

 Mr Alderson believed at that time (November 28, 1841), that the Dead 

 Sea was about 1400 English feet below the level of the Mediterranean. In 

 a more recent communication by Lieutenant Symonds (Jameson's Jour- 

 nal, voL xxxiv. p. 178), the amount of 1312 English feet is given as the 

 final result of two trigonometrical operations agreeing very nearly 

 with each other. 



t 8ur la Mohiliti du fond dc la Mcr Casjncnne in my Asie Ccntrale, t. 

 ii., pp. 283-294. At my request, the Imperial Academj' of Sciences of 

 St Petersburg, in 1830, caused the learned natural philosopher Lenz to 

 cut fixed marks at particular points (indications shewing the mean level 

 of the water at a certain epoch) at Baku, in the Peninsula of Abscheron. 

 In 1839 also, in a supplement to the instructions given to Captain Ross 

 for the Antarctic expedition, I urged that marks should be cut in the 

 rocks of the southern hemisphere, wherever there was an opportunity, 

 in the saine m.anner as in Sweden and on the shores of the Caspian Sea. 

 If this had been done in the early voj'ages of Bougainville and Cook, 

 we should now know if the secular alteration of the relative heights of 

 the sea and land is to be regarded as a general, or only as a local, natural 

 phenomenon ; and if a law can be recognized as to the direction of the 

 points which rise aad sink simultaneously. 



