Geology 



Here, with the object of ascertaining the ultimate 

 destination of the water, we dissolved our fluorescein in 

 a small dam which we had constructed at the side of the 

 stream by means of stones and turf. When it was 

 thoroughly dissolved we had a deep orange-red liquid, 

 which on being allowed to flow into the main stream 

 and become diluted turned into a glorious vivid green, 

 which glittered in the sunlight and formed, as it rippled 

 and splashed over the stones, a spectacle not readily 

 forgotten. Having watched the green water flow down 

 the sink for some minutes and arranged the dam so that 

 the remaining portion of its contents might dribble 

 slowly into the stream in such a manner as to spread 

 the supply over several hours, we made an inspection of 

 the locality to see if we could find any opening which 

 would admit us to the underground channel. In this 

 search we were unsuccessful,. as the water sank amongst 

 loose rounded boulders which completely covered the 

 floor and sides of the crater-like hollow. 



As we calculated that several days must elapse 

 before the green water made its appearance at any of 

 the springs in the valley, we decided to make a further 

 collection of fossils from the limestone hills beyond the 

 lake, and therefore made for our old camp beneath the 

 pines. 



The fossils were collected bed by bed and a carefully 

 measured section was made as the work proceeded, 

 similar numbers being affixed to the specimens and to 

 the beds of rock in the section. The spoils were care- 

 fully packed for transport to the steamer at Lyell, where 

 they could be investigated at leisure. Extensive col- 

 lections were also made from the Silurian rocks which 



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