360 Mr. J. Y. Buchanan [May 29, 



work before the beginning of 1872. The late Professor Sir Wyville 

 Thomson was made director of the scientific staff, and I was fortunate 

 enough to be selected as the chemist and physicist of the expedition, 

 for which I owe him a debt of gratitude that I can never repay. 



On the naval side the expedition was particularly lucky. Admiral 

 Richards was the hydrographer and was probably the most experi- 

 enced surveying officer of the time. He entered into the proposed 

 expedition with the greatest enthusiasm, and in Captain Nares he 

 appointed the best officer of his department to the command of the 

 ship. Captain Nares and the officers who had served with him in 

 various ships and who followed him to the Challenger had already 

 had abundance of experience of sounding and other observations in 

 great depths, so that when the Challenger sailed it was with a naval 

 staff which thoroughly knew its business. Owing to the early 

 selection of the civilian scientific staff it also was able to start 

 thoroughly knowing its business in so far as that could be known at 

 the time, and the principal thing that it had to acquire was its sea 

 legs. The tempestuous weather of the first ten days of the cruise 

 enabled it to acquire these without delay. 



Almost all the men to whose influence the expedition was due 

 are dead. Those who at present are most active in the furtherance 

 of the science of oceanography were then children, and notwith- 

 standing the voluminous reports of the voyage, it is difficult for 

 the student of to-day to realise what were the views and expectations 

 thirty years ago which determined the procedure of the Challenger in 

 breaking ground in the vast dominion of the sea. I propose to-night 

 to illustrate this with one or two examples. The subject is more 

 fully dealt with in a paper entitled ' A Retrospect of Oceanography 

 during the past Twenty Years ' published in the Report of the sixth 

 International Congress at London in 1895. 



Continuity of tJie Chalk. — The effect of the work of the Bulldog 

 and of Dr. Wallich's report on it was to produce the belief which was 

 generally expressed by saying, that at the present time chalk is 

 being laid down all over the deep ocean, that therefore, geologically 

 speaking, the bottom of the ocean is a contemporary cretaceous 

 formation. Thus Wyville Thomson,* after pointing out that where- 

 as the chalk of our downs consists of almost pure carbonate of 

 calcium with no silica, the chalk mud of the Atlantic contains as 

 much as twenty or thirty per cent, of silica, and that English chalk 

 is the very purest of its kind, he goes on to say, " There can be no 

 doubt whatever that we have forming at the bottom of the present 

 ocean a vast sheet of rock which very closely resembles chalk ; and 

 there can be as little doubt that the old chalk, the cretaceous forma- 

 tion which, in some parts of England, has been subjected to enormous 

 denudation, and which is overlaid by the beds of the Tertiary series, 

 was produced in the same manner and under closely similar circum- 



* ♦ Depths of the Sea,' p. 470. 



