8 i THE DEPTHS OF THE SEA. [ciiAr. jii. 



As it was intended that tlie exploration in the 

 ' Porcupine ' in the summer of 1869 should occupy 

 much more time, and if possible be much more 

 thorough than that in the ' Lightning ' the year 

 before, the preparations for the ' Porcupine ' expedi- 

 tion were much more elaborate and comprehensive. 

 The Committee of the Eoyal Society were desirous 

 that various important questions as to the physical 

 condition and chemical composition of the water at 

 great depths should be investigated ; and the singular 

 temperature results of the former cruise ably discussed 

 by Dr. Carpenter in his preliminary report had excited 

 so much curiosity and interest that their further elu- 

 cidation was regarded as vicing in importance with 

 that of the distribution and conditions of animal life. 

 It was consequently decided that the naturalists direct- 

 ing the expedition should be accompanied by assistants 

 trained in chemical and physical w^ork, and the chart- 

 room of the vessel was fitted up as a temporary 

 laboratory, with physical and chemical apparatus and 

 microscopes. 



The vessel was available from the beginning of 

 May to the middle of September, and as it was im- 

 possible for those who had conducted the previous 

 expedition to be absent so long from their puhhc 

 duties,- it was resolved to have three separate cruises ; 

 and Mr. Gwyn Jeffreys, P.R.S., whose co-operation 

 was specially valuable from his thorough knowledge 

 of the species and distribution of recent and fossil 

 mollusca, was associated with Dr. Carpenter and 

 myself, and undertook the scientific charge of the 

 first cruise. 



jVIr. Gwyn Jeffreys was accompanied by Mr. AT. 



