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220 C. E. Dutton— Hawaiian Volcanoes. 
the great pit thoroughly and also the country round about. 
If I can rightly estimate the accounts of observers who saw 
Kilauea forty years or more ago, I should infer that the total 
amount of volcanic energy now manifested there has very con- 
siderably diminished. There is difficulty, however, in forming 
an estimate of how much allowance should be made for the 
yourself, in 1841, has been completely filled up. The great 
outer cavity also has, I infer, become notably shallower, hav- 
ing been partially filled by innumerable overflows of lava. 
The inner cavity, which once held a burning lake, is now rep- 
resented by two lakes, whose united surfaces have, I should 
judge, an extent which is but a small fraction of the surface of 
the old lake of forty or fifty years ago. These two lakes are 
both situated with their surfaces at levels higher than the 
mean level of the main floor of the pit. I infer too that they 
are much more languid and sluggish in their action than the 
lake which you saw. 
The height of the walls surrounding the pit varies from 320 
to 740 feet. There is abundant evidence that the floor of the 
pit sinks down more or less after every eruption within it, but 
presumably not to so great an extent as to compensate the 
building up of the floor after the successive out-pours of lava, 
so that, on the whole, the pit is probably growing shallower. 
I watched, with the deepest interest, the action of the lava 
in the lakes. The most accessible one is now called the New 
Lake. It undergoes a series of regular changes within 4 
period of about two hours. When we reach the brink of 
it we generally find it frozen over and quite black and still, 
except at the edges, where we perceive a rim of fire. We 
observe also at many places upon the edges a little sputtering 
and blowing out of lava and hear a dull simmering sound. 
length a piece of the black lava upon the surface cracks, turns 
down its edge and sinks, disclosing a patch of livid fire. 
n after in some other part of the lake, at the edge, another 
piece breaks and goes down. This becomes more and more 
frequent until at last a hundred cracks suddenly shoot through 
the entire surface, and, with a grand commotion, numberless 
