ILLUSTRATIONS (1). ELEVATION OF VESUVIUS. 377 



C. The elevation of the cone of scoriae that fell into the 

 Crater on the 22nd October, 1822. 



Feet. 



Lord Minto, barometrically . . . 4156 



Brioschi, trigonometrically, according to different com- 

 binations 



Either 4067 



Or 4099 



The most probable final result for the height of the cone 

 of scoriee that fell in during the year 1822, is 4131 feet. 



D. Punta Nasone, the highest summit of the Somma. 



Schuckburgh (1794), barometrically, probably accord- 

 ing to his own formula . . . .3734 



Humboldt (1822), barometrically, according to the 



formula of Laplace 3747 



E. Plain of the Atrio del Oavallo. 



Humboldt (1822), barometrically .... 2577 

 F. Base of the cone of ashes. 



Gay-Lussac, Leopold von Buch, and Humboldt (1805), 



barometrically 2366 



Humboldt (1822), barometrically .... 2482 



G. Hermitage of Salvatore. 



Gay-Lussac, Leopold von Buch, and Humboldt (1805), 



barometrically 1918 



Lord Minto (1822), barometrically . . . .1969 

 Humboldt (1822), again barometrically . . .1974 



Some of my measurements have appeared in Monticelli's 

 Storia de* fenomeni del Vesuvio, avvenuti negli anni 1821 

 1823, p. 115, but owing to the correction of the height 

 of the mercury in the cistern having been omitted, the 

 numbers are not given with perfect exactness. When it 

 is remembered that the results contained in the above table 

 were obtained with barometers of very different construction, 

 at different hours of the day, during the prevalence of various 

 winds, and on the unequally heated declivity of a volcano, in 

 a locality where the decrease of the atmospheric temperature 



