Postscript to No I. Account of Mount Vesuvius. 125 



isted between the higher and lower edges of the crater (500 

 feet) by Humboldt's own account. From the general accu- 

 racy of the statements, and the evidence of my own senses, I 

 am disposed to maintain, in great part at least, the numbers I 

 have already given. 



Another inconsistency which I at first believed existed in 

 Humboldt''s paper, that of stating the proportion of the cone 

 of ashes to the total height as one to tefi, instead of one to three, 

 in contradiction to his own personal narrative, (See last Num- 

 ber, p. 1 96,) I found to arise from an erroneous translation given 

 in a contemporary journal, which, in presenting this paper to 

 the English reader, has omitted, I think, the most valuable 

 part of it, — the statements of heights of the various portions of 

 the mountain at different times, with which, I think, the reader 

 will thank me for presenting him, as I consider them extreme- 

 ly valuable. 



A. Rocca del Palo. Highest N. W. summit above the sea. 



Toises. 



Saussure, 1773, barometric measurement, - 609 



Poh, 1794^, ditto. - - - 606 



Breislak, 1794, ditto. - - - 613 



Gay-Lussac, De Buch, and Humboldt, 1805, ditto. 603 



Brioschi, 1810, trigonometric measurement, - 638 . 



Visinti, 1816, ditto, - - , - 622 



Lord Minto, 1822, barometer, - - - 621 . 



P. Scrope, 1822, ditto, (slightly uncertain) - 604 



Monticelli and Covelli, 1822, - - - 624 



Humboldt, 1822, - - - - 629 



Probable result, 625 toises above the sea, 317 above the 

 hermitage. 



B. Lowest edge of the crater, (S. E.) 

 1794, - - - - 559 



Gay-Lussac, De Buch, and Humboldt, 1805, - 554 

 Humboldt, 1822, - - - - 546 



C. Height of the cone of Scoriae in the crater 1822, 



above the level of the sea. Lord Minto, (barometer) 650 



Brioschi, (various trigonometric operations) - 636 



or, - - 641 



