xlviii THE VOYAGE OF H.M.S. CHALLENGER. 



water at different temperatures arc moving about, each in its particular course; maintain- 

 ing a remarkable system of oceanic circulation, and yet keeping so distinct from one 

 another that an hour's sail may be sufficient to pass from the extreme of heat to the 

 extreme of cold. 



" Finally, it had been shown that a large proportion of the forms living at great 

 depths in the sea belong to species hitherto unknown, and that thus a new field of bound- 

 less extent and great interest is open to the naturalist. It had been further shown that 

 many of these deep-sea animals are specifically identical with tertiary fossils hitherto 

 believed to be extinct, while others associate themselves with and illustrate extinct groups 

 of the fauna of more remote periods ; as, for example, the vitreous sponges illustrate and 

 unriddle the ventriculites of the chalk." l 



In consideration of the value and novelty of these results, the Royal Society urged 

 the Admiralty to provide means of extending the observations. In 1869 the surveying 

 ship " Porcupine," Captain Calver, was appointed to this service. In addition to 

 the temperature observations, which had turned out so interesting. in the " Lightning," it 

 was decided to make a number of chemical observations on the water. For this purpose 

 the chartroom was fitted up as a laboratory, and a chemist was invited to join the 

 biologists on the cruise. A number of arrangements were also made for facilitating 

 dredging and the subsequent observations. The "Porcupine" was a first-rate vessel 

 for the purpose, and between May and September 1869 she made three distinct trips. 

 The first of these was under the scientific direction of the late Mr. Gwyn Jeffreys, 

 and it was chiefly devoted to dredging off the west coast of Ireland and in the 

 channel between Scotland and ilockall. The deepest dredging made was in 1470 

 fathoms, and no lack of life was found at that depth. It was accordingly resolved 

 that, during the second trip, under the direction of Professor Wyville Thomson, 

 an attempt should be made to dredge in the deepest water within reach, so that a 

 definite answer to the general question of the existence of life at great depths could 

 be arrived at. The " Porcupine " was steered for the Bay of Biscay, and at a point about 

 250 miles west of Ushant two highly successful hauls of the dredge were taken in water 

 over 2000 fathoms deep, and in both animal forms from the Protozoa to the Mollusca 

 were abundant. 2 It was on this cruise that Captain Calver suggested the employment of 

 hempen tangles attached to the dredge frame, an idea which Professor Thomson says 

 inaugurated a new era in dredging. 3 



The third cruise of 1869, during which Dr. Carpenter was the naturalist in charge, 

 was intended to be a repetition of that of the " Lightning " in the previous autumn. 

 The observations of the earlier expedition were confirmed and extended in various 

 directions. 



In 1870 Mr. Gwyn Jeffreys and Dr. Carpenter continued the work in the 



1 Depths of the Sea, pp. 79, 80, 1874. 2 Ibid, pp. 96, 97. 3 IbU., p. 256. 



