i 2.) @& 
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S4 THE DEPTHS OF THE SEA. [CHAP. Ill. 
As it was intended that the 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 Royal Society were desirous 
that various important questions as to the physical 
condition and chemical composition of the water at 
ereat 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 vieing 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 work, 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 eonducted the previous 
expedition to be absent so long from their public 
duties, it was resolved to have three separate cruises ; 
and Mr. Gwyn Jeffreys, F.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. 
Mr. Gwyn Jeffreys was accompanied by Mr. W. 
