80 INTENSIVE ROCKS IN THE ESKDALE NEIGHBOURHOOD. [Feb. I909. 



much lower, and he thought that the fusion-point of quartz would 

 be low. He considered that the neglect of experimenters to recog- 

 nize the quartz-tridymite transformation-point might explain their 

 difficulty in determing the true fusion-point of micropegmatite. 



The Author thanked Dr. Teall for his complimentary remarks 

 upon the paper, and Mr. Barrow for his suggestion that an eutectiu 

 of quartz and water might have played an important part in the 

 history of the rock ; and said that, if this were the case, the difficulty 

 raised by another speaker with regard to the high temperature of 

 the magma at the time of intrusion might be removed. He also 

 expressed his full accord with the views of Mr. Cosmo Johns on 

 the subject of eutectics, and acknowledged many valuable sugges- 

 tions which he had from time to time received from him. With 

 regard to the question of two liquid phases, the Author pointed 

 out that evidence of the existence of such phases was difficult 

 to obtain ; but that, if they could be shown to have existed, many 

 difficulties might be removed. 



He welcomed Mr. Green's remarks as to the age of the intrusion, 

 and pointed out that the only direct evidence on this subject was 

 that the granite was intrusive in Ordovician rocks and apparently 

 covered unconformably by the Trias. The dyke of quartz-porphyry 

 on the Screes was indeed displaced by faults, but these probably 

 did not belong to the great pre-Devonian movement, as their 

 lines were frequently occupied by doleritic dykes which were the 

 latest intrusions in the area and. were probably of Tertiary age. 



In conclusion, the Author thanked the Fellows for their cordial 

 reception of his paper. 



