1865.] BRITISH ASSOCIATION. 341 



returns the friendly impulse. If we look back on the work of 

 previous years, it is easy to mark the special action of the Associa- 

 tion in fields which hardly could be entered by any other adven- 

 turers. 



Many of the most valuable labors of which we are now reap- 

 ing the fruits were undertaken in consequence of the reports on 

 special branches of science which appear in the early volumes of 

 our Transactions — reports in which particular data were requested 

 for confirming or correcting known generalisations, or for establish- 

 ing new ones. Thus, a passage in Professor Airy's report on 

 Physical Astronomy (o) first turned the attention of Adams to the 

 mathematical vision of Neptune ; Lubbeck's Report on Tides (p) 

 came before the experimental researches and reductions, which 

 since 1834 have so often engaged the attention of Whewell and 

 Airy and Haughton, with results so valuable and so suggestive of 

 further undertakings. Among these results may be placed additional 

 knowledge of the probable depth of the channels of the sea. For, 

 before the desire of telegraphic communication with America 

 had caused the bed of the North Atlantic to be explored by 

 soundings to a depth seldom exceeding three miles, there was 

 reason to conclude from the investigations of Whewell on Cotidal 

 Lines (q) that a depth of nine miles was attained in the South 

 Atlantic, and from the separate computations of Airy and Haugh- 

 ton that a somewhat greater depth occurred in a part of the course 

 of the tide-wave which washes the coast of Ireland (r). The 

 greater portion of the sea-bed is within the reach of soundings 

 directed by the superior skill and greater perseverance of modern 

 scientific navigators ; a depth of six miles is said to have been 

 reached in one small tract of the North Atlantic ; depths of nine 

 or ten miles in the deepest channels of the sea are probable from 

 considering the general proportion which is likely to obtain be- 

 tween sea-depths and mountain-tops. Thus the data are gradually 

 being collected for a complete survey of the bed of the sea, includ- 



(o) Reports of the British Association for 1832, p. 154. Laplace had 

 indeed observed that " the planet Uranus and his satellites, lately dis- 

 covered, give reason to suspect the existence of some planets not yet 

 observed-" thereby encouraging the search for new discoveries, in our 

 own system.— (Exp. du Syst. du Monde, 1799, 4to, p. 350.) 



(p) Reports of the British Association, 1832. 



(9) Trans, of Roy. Soc, 1833. 



(r) Trans, of Roy. Irish Acad., 1855. 



