Volcanic Eruptions on Hawaii. 349 
diminishing eastward to a single degree, so’ that the region of vol- 
canic action subordinate to Mount Loa, is about seventy miles in 
width, or includes the entire breadth of the island, from east to 
west. ‘The main part of the mountain, if considered a portion of 
a great sphere,* will correspond to a segment 13,760 feet deep, 
Uy Me Y, Wi 
g YF) Wty re 
WH 
=—- ——_ 
a 
he dome, consequently, instead of having slender walls at top, 
has a horizontal thickness of full twenty miles, eighteen hundred 
feet Vertically below its summit. ‘ 
> 
* It varies a little from a segment of a sphere, the upper parts being slightly more 
prominent. ite Gai 
_+ For comparison with other lofty volcanic mountains we here mention a few 
other inclinations, mama rent instances, ying oh poe 
, rhe peak of Teneriffe has an average inclination of 12°30’, the proportion of 
eight to eter being given as 1 to 9. ene tis igs 
“ , according to Elie de Beaumont, has an average inclination of 8degrees. M. 
Von. Buch makes the ratio of height to circumference as 1 to 34, giving ang! dots 
x 
n ier beiageaho seats 
degrees e Chimborazo dome, aceording to Humboldt, is only 673 toises through 
a level of 153 toises (or 978 feet) below the centre of top. 
At is much to be t artists, when sketching mountains, are not content 
i ion nod thaveeat thei its, Even in works of science, the 
ening up their sides, and sharpening their summits, Ey work ve, th 
€ errors are common. We never seé a drawing of Jorullo, which does not give 
Same erro 
the peak actually impossible slopes, taking Humboldt’s own facts as a criterion 
awin : ; s 3 
are al gives reli 
. A simple outline, if correct, I 
ble to science, than one improved to suit the fancy, though 
