PRESENT CONDITION OF THE FLOOR OF THE OCEAN; 

 EVOLUTION OF THE CONTINENTAL AND OCEANIC 

 AREAS. ^ 



By Sir John Murray, K. C. B., F. R. S. 



In his opening address to the members of the British association at 

 the Ipswich meeting, the president cast a retrospective glance at the 

 progress that had taken place in the several branches of scientilic 

 inquiry from the time of the formation of the association in 1831 down 

 to 1895, the year in which were published the last two of the fifty vol- 

 umes of reports containing the scientific results of the voyage of 

 H, M. S. Challenger. In that very able and detailed review there is 

 no reference whatever to the work of the numerous expeditions which 

 liad been fitted out by this and other countries for the exploration of 

 the depths of the sea, nor is there any mention of the great advance 

 in our knowledge of the ocean during the period of sixty -five years 

 then under consideration. This omission may be accounted for by 

 the fact that at the time of the formation of the British Association 

 knowledge concerning the ocean was, literally speaking, superficial. 

 The study of marine phenomena had hitherto been almost entirely 

 limited to the surface and shallow waters of the ocean, to the survey 

 of coasts and of oceanic routes directly useful for commercial pur- 

 poses. Down to that time there had been no sj^stematic attempts 

 to ascertain the physical and biological conditions of those regions of 

 the earth's surface covered by the deeper waters of the ocean; indeed, 

 most of the apparatus necessary for such investigations had not yet 

 been invented. 



The difiiculties connected with the exploration of the greater depths 

 of the sea arise principally from the fact that, in the majority of cases, 

 the observations are necessarily indirect. At the surface of the ocean 

 direct observation is possible, but our knowledge of the conditions 

 prevailing in deep water, and of all that is there taking place, is almost 

 wholly dependent on the correct working of instruments, the action 

 of which at the critical moment is hidden from sight. 



^Address of the president of the geographical section of the British Association for 



the Advancement of Science, at the Dover meeting, 1899. Reprinted from Eeport 



of the British Association, 1899, pp. 789-802. 



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