J.D. Dana on Volcanic action at Mauna Loa. 243 
contains material enough for one hundred and twenty-five Ve- 
suviuses: and two thousand feet below its summit it has a thick- 
hess of twenty miles,—a massiveness in the great voleano that 
would seem to fit it for lofty projection towards the celestial re- 
gions; and yet it makes out to toss its little cinders a few hun- 
dred feet when it does its best. This is not strange, when it 
is understood that in a boiling fluid, whether lava or anything 
else, the projectile force of the escaping vapors depends on the 
viscidity of the fluid, and also the narrowness of the vent above : 
and where the lavas have the fluidity that enables them to make 
craters three miles in diameter and mountains fifty miles broad, 
or the far larger dimensions that are observed in the moon, they 
pended on some accidental ingress of waters, or formation o 
vapors. But on Hawaii, both Kilauea and also the central or 
summit crater of M. Loa show that after an eruption there isa 
gradual progress in the lavas, until their accumulation and the 
In 1849, it was again filled, but afterwards became quiet, the 
lavas sinking away, though without a sinking of the craters 
bottom. There was evidence in this of a partial eruption, 
though the fissures did not reach the surface of the island. Ac- 
cording to the account by Mr. Coan, Kilauea was again the past 
year in extraordinary activity: and whether it will this time 
break through to the surface remains to be seen. 
