NOTES. XCU1 



by the barometric measurements of Count Bertou, the far more careful ones 

 of Russegger, and by the trigonometrical measurements of Lieutenant Symond, 

 of the British Navy. By a letter from Mr. Alderson to the Geographical 

 Society of London, communicated to me by my friend Captain Washington, 

 the measurement of Lieutenant Symond gave the level of the Dead Sea at 

 1506 French feet (1605 English feet) below the highest house in Jaffa. Mr. 

 Alderson, at that time (November 28, 1841), considered the Dead Sea to be 

 about 1314 feet (1400 English) below the level of the Mediterranean. In a 

 more recent communication of Lieutenant Symond (Jameson's Edm. New 

 Philos. Journal, Vol. xxxiv. 1843, p. 178), he gives 1231 feet (131 2 English) 

 as the final result of two very accordaut trigonometric operations. 



(S 54 ) p. 288. Sur la Mobilite du fond de la Mer Caspienne, in my Asie centr. 

 T. ii. pp. 283 294. At my request, the Imperial Academy of Sciences at St. 

 Petersburgh charged the learned physicist, Lenz, with fixing solid and well- 

 secured marks on the peninsula of Abscheron, near Baku, for the purpose of 

 shewing the mean level ot the water at a given epoch. In a similar manner 

 I requested and obtained the insertion, in the supplementary instructions given 

 to Captain James Ross for the Antarctic expedition, of a direction to fix marks, 

 at suitable places, on the cliffs and rocks of the Antarctic Seas, as has been 

 done in Sweden and on the Caspian. If similar measures had been taken in 

 Cook's and Bougainville's earliest voyages, we should now be in possession of 

 the necessary data for determining whether secular variation in the relative 

 level of land sea is a general or a merely local phenomenon, and whether 

 any law is discoverable in the direction of the points which rise or sink 

 simultaneously. 



t 355 ) p. 288. On the sinking and rising of the bottom of the sea in the 

 Pacific, and the different areas of alternate movements, see Darwin's Journal, 

 pp. 557 and 561566. 



P) p. 291. Humboldt, Rel. hist. T. iii. pp. 232234. Compare also 

 eonie ingenious remarks on the form of the Earth and the position of its lines 

 of elevation, in Albrechts von Roon Grundziigen der Erd-Volker-und Staaten- 

 kuude, Abth. i. 1837, S. 158, 270, and 276. 



p 7 ) p. 292. Leop. von Buch iiber die geognostischen Systeme von 

 Deutschland, in his Geogu. Briefcn an Alexander von Humboldt, 1824, pp. 

 265 271 ; and Elie de Beaumont, Recherches sur les Revolutions de la 

 Surface du Globe, 1829, pp. 297307. 



P) p. 292. Humboldt, Asie centrale, T. i. pp. 277283 ; Essai sur le 

 Gisemer.t des "Pochos, !S nc ? r -p. 57 ; ai '. T. 'n. pp. ' !- guft 



