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



1858, and published his famous Sailing Directions embodying these statistics. One 

 important result of Maury's exertions was the maritime conference held in Brussels in 

 1853, which resulted in international observations being taken on many naval and 

 mercantile ships, thus obtaining several of the advantages of scientific expeditions at 

 very little expense. 



Before 1850 the attention of the Norwegian naturalist, Michael Sars, had been 

 directed to the bathymetrical distribution of life on his native coasts, and he published in 

 the following year a list of thirteen species which lived at a depth of about 300 fathoms. 1 

 His son, G. 0. Sars, afterwards assisted him in the work of deep-water dredging, and the 

 result was, in 1864, a list of ninety-two species, which lived between the depths of 200 

 and 300 fathoms. 2 A few years later these untiring investigators found abundance of 

 life at the bottom under 450 fathoms of water. 3 



A great impulse was given to deep-sea soundings when Brooke, an officer in the 

 United States Navy, invented his sounding machine in 1854. Its principle was that 

 described by Hooke two centuries before ; the sinker was detached when the weight struck 

 the bottom, but it differed in that the sounding tube could be drawn up by the line, 

 bringing with it a small sample of the deposit on which it struck. Bailey's description 

 of the micro-organisms found in these deposits, as well as others obtained by the 

 U.S. Coast Survey, excited great interest among scientific men. 4 A few years later the 

 instrument was modified and improved by Commander Dayman, who employed it for 

 his soundings across the Atlantic, when investigating the depths through which the 

 Atlantic telegraph cable would recpiire to pass. 5 The necessity for ascertaining the form 

 and conditions of the sea bed for telegraph purposes was the occasion of considerable 

 increase in the scientific knowledge of great depths. 



The samples of "Atlantic ooze" procured from the greatest depths of that ocean by the 

 sounding rods of the telegraph ships were eagerly examined by the leading European and 

 American naturalists. The ooze was found to consist largely, in some cases almost wholly, 

 of the shells of Foraminifera and the siliceous skeletons of Radiolarians and Diatoms. 

 The question soon came to be whether all the Foraminifera naturally lived on the bottom, 

 or whether it was only their dead shells that collected there, the animals living and dying 

 on the surface, or at some intermediate depth. This cpiestion was exceedingly difficult 

 to settle from the data possessed by the disputants prior to the Challenger and other 

 exploring expeditions. 



1 Keretning 0111 en i Sommeren 1849 forelagen zoologisk Keise i Lofoten og Finmarken, Nyt May. f. Naturvid., 

 Bd. vi. p. 133, 1851. 



2 Bennerkninger over (let ilyriske Livs Uilbredning i Havets Dylxler, ForhandL Vidttuk. Seld:, Christiania, p. 54 

 (1864), 1865. 



3 ForhandL Vidensk. Selsk., Christiania, p. 248 (1868), 1869 ; translation, Ann. and May. Nat. Hist., ser. 4, vol. iii. 

 p. 425, 1869. 



4 Amer. Journ. Sci. and Arts, vol. lxxi., 1856. 

 6 Depths of the Sea, p. 214. 



