370 PACIFIC OCEAN. 
at an angle not exceeding three degrees; and subsequently, by 
forces below its centre, to be raised to a conical shape. It is ad- 
mitted by this distinguished geologist, that the forces may have been, 
for a short distance, linear in direction, though approximately central. 
The actual formation of cones in Kilauea, exact models of the great 
mountain-volcanoes, beginning and progressing as cones, is better 
evidence on this point than any supposed impossibility of lavas de- 
scending rapid slopes ; for we have shown that the conical form com- 
mences through eruptions from the terminal vent and fissures, and 
undergoes no essential change, as enlargement goes on. We see no 
foundation whatever in the Pacific for the view that the mountains 
waited till the material was thrown out before the action began which 
elevated the centre. We are taught rather that the elevating forces 
were more powerfully at work in the earlier periods, when the moun- 
tain structure was begun. In its very earliest origin, if ever, the 
centre would be radiately fissured, and the angle of acclivity in- 
creased ; and this effect would gradually diminish as the size and 
activity of the crater diminished, and the general action subsided, or 
became generally lateral through flank fissures. While, therefore, 
we present no opinion here as to the particular cases claimed as 
instances of elevation craters, we cannot admit the hypothesis to the 
rank of a general theory.* 
* As a more distinct enunciation of some of the principles to which we have been led 
by our investigations, we may notice here some of von Buch’s deductions, not in accord- 
ance with facts as we have observed them. 
On page 296 of his Canary Islands, he says, that in “all craters of eruption,” (the 
term used to distinguish certain craters from supposed craters of elevation,) * the craters 
are broken down on one side.” What is Mount Loa on this principle? Lavas have 
flowed from its summit even at a height of fourteen thousand feet, ten thousand feet above 
Kilauea ; and although issuing through an opened fissure, it is properly no less a crater 
of eruption. The Kilauea lavas are as high above the sea as the peak of Vesuvius; yet 
they accumulate over a large area till the bottom is raised near four hundred feet, when 
the mountain yields to the pressure, and the lavas flow out. Here is eruption, as much 
as if the sides of the mountain held their ground and the crater had overflowed; yet the 
crater is not broken down on one side. If Mount Loa should be ranked with craters of 
elevation, we should be equally troubled to distinguish a correspondence with the charac- 
ters given for this class of volcanoes. If the prevalence of fissure eruptions be the 
evidence, we reply, that this may proceed from subsiding fires, or from a general eleva- 
tion of the mountain in which the whole island has participated: no raising of the centre 
by a sudden movement at any period in its history can be proved by any facts apparent; 
and none is needed to explain the phenomena. The actual change which the preceding 
descriptions sustain, is a change from a state in which eruptions produced an increase in 
