3 
able that in the spring of 1869 it was determined by the Royal Society to 
make a further effort and ask the Government to grant another vessel, 
so that the observers might go out with all the experience gained in 
the first cruise, and not only confirm the particular observations then 
made, but also investigate other questions which were opened by those 
researches. Accordingly in May, 1869, H.M.S. Porcupine, one of the 
surveying ships of the Navy, Staff-Commander E. K. Calver, R.N., was 
fitted out with every kind of apparatus which experience could suggest. 
The Porcupine was engaged in the investigations from the end of May to 
the first week in September. Speaking broadly three sets of inquiries 
were conducted, (1) an investigation into the temperature of the sea at 
great depths, with a view to ascertain the extent and direction of the sub- 
marine polar currents supposed to exist ; (2) an inquiry into the existence 
and distribution of animal life on the sea bottom at these depths ; and (3) 
an examination of the nature of the water at different depths, for its physical 
and chemical properties, the amount and nature of the gases dissolved in 
it, &c. During the first half of the cruise the zoological inquiries were 
under the charge of Mr. Gwyn Jeffreys, F.P.S., the celebrated conch olo- 
gist, and the physical and chemical investigations under that of the speaker, 
and the area of their work was the very deep water about 200 miles off 
the west coast of Ireland, extending as far north as Rockall. The next 
portion of the cruise, under the charge of Prof. Wyville Thomson, F.R.S., 
and Mr. John Hunter, both of Belfast, explored the extreme depths off the 
south-west coast of Ireland and the north-west coast of France ; and during 
the last three weeks under Dr. Carpenter and Prof. Thomson, assisted by 
Mr. P. H. Carpenter, the investigations were carried on in the triangular 
area bounded by imaginary lines drawn between the Faroes, Shetlands, and 
Hebrides, in which the " Lightning" had been engaged in 1868, It will 
be convenient to consider together the results of the first and second por- 
tions of the cruise, reserving until later those of the third division. 
The apparatus employed was described in detail, the explanations being 
aided by diagrams. The dredge was of the ordinary form of * ' N aturalist's 
dredge,'' but much larger, stronger, and heavier. For very deep water 
the weight of the dredge employed was nearly 8 cwt., but for shallower 
depths a lighter dredge sufficed. The bag was so contrived, that it could 
be easily detached from the iron frame, and was made of closely-netted 
sounding line, an inner bag of fine canvass being provided which was readily 
turned inside out to empty the contents, and was always washed between 
each time of using, to avoid the possibility of error as to the locality of any 
