GEOLOGY AND MINERALOGY. 
59 
more rapid at that period when the land being higher attracted more 
clouds, and consequently there was greater rainfall, and probably 
snow water to assist the process. Although this action is sufficient 
to account for the present size and appearance of these ravine- I am 
inclined to think that they had their rudimentary origin or their 
courses traced out previous to their enlargement by running water 
in the sheets of lava as they spread outwards from the crater’s ed«-e 
m a semi-fluid or viscous state. Flowing in a sluggish manner, the 
outer edge of the lava would naturally terminate in a form somewhat 
similai to that of the fingers of a human hand when spread out 
a upon ie palm ; each subsequent flow or stratum taking the 
same course and shape, the spaces left between the fingers, as it 
veie, would represent the commencement of the ravines. That the 
avas iave travelled very slowly is evidenced by the elongation, in 
cnee ion of the flow, of the air cavities contained in them, as 
T tlle remarkable forms which the scum has assumed 
W 616 las accu mulated, before cooling, very like the froth 
on the surface of stagnant water. In the locality of High Knoll 
and Ladder Hill, this hardened scum so greatly resembles in texture 
* e stems °f frees as to be commonly mistaken for petrified wood. 
’; ome of it is so scoriaceous or full of minute cavities that it floats 
for a considerable time when placed in water ; it is, in fact, a kind 
of coarse pumice. 
A confirmation of the opinion that the larger ravines had their 
origin in the flows of lava, I think, may be obtained by walking 
along the ridge, or present crater edge, and noticing the natural 
forms of the spurs or divisions which separate one from the other 
Standing on Diana’s Peak, and looking down eastward, the flow of 
lavas appears to have taken two directions. One stream, that nearest 
to the hill on which stands Sunberry Cottage, has flowed irregularly 
for about a quarter of a mile easterly, when it seems to have 
divided ; one branch has flowed northerly towards Prosperous Bay 
on which is situated Arnos Yale, and now shows a very ruo-o-ed 
steep ridge for about a mile, until it reaches “ Shark’s Valley,” when 
it turns in an easterly direction towards George’s Island, and then 
gradually slopes down, losing itself in Shark’s Valley, about three- 
quarters of a mile distant from the sea shore ; the other branch seems 
to have travelled on still more easterly, forming that very irregular 
portion of the Island lying between Stone Top Bay and Deep 
