The Pool Subsides. 



213 



not have overflowed all round simultaneously. Has the higher edge been raised or 

 the lower edge been depressed? If so where are the faults in the wall ? 



On Friday, September 4th, in the early afternoon the fountains ceased to play, 

 and soon the subsidence of the pool began. Parties coming up from the pit at dusk 

 reported the fall at several hundred feet, but the light as seen from the Volcano House 

 and reflected on passing clouds did not seem less than it had been when darkness came 



Fig. IJ9. HALEMAl'iMAU FROM THE NORTHWEST IN I908. I'ERKINS. 



on. Mr. C. B. Thompson, Mr. Chas. N. Forbes and myself at once started for the 



Halemaumau. The earth light was still sufficient to show the path. P\\\ over the 



surface of the pool, which had fallen perhaps a hundred feet generally, but much lower 



on the northern side under the observation hut, were bright lights, and most of these 



remained stationary during our visit. 



In the centre of the pit was a curious break running east and west, at the edge 



of which was a vertical slab of lava, semicircular in form, resembling half a mill-stone, 



and other slabs continued the wall for some distance. Over these fell a cascade of 



C591] 



