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Ie ne fay rien sans Gayete (Montaigne, Des livres) Ex Libris Jose Mindlin V\ % WW^. I/X/V^ . ^1K Fogflge of tije 'CDfjaUenger.' THE ATLANTIC. T l^Wy.-O Zl Onaba/it&O' -w te^Jr'far/i a- oVicUvif/JA Z'srdiTi Pi-Mishsiby Mcu.mdla.ri, & C? THE ATLANTIC A PRELIMINAEY ACCOUNT OF THE GENERAL RESULTS OF # THE. EXPLORING VOYAGE OF H.M.S. 'CHALLENGER' DURING THE YEAR 1873 AND THE EARLY PART OF THE YEAR 1876 BY SIR C. WYVILLE THOMSON KNT., LL.D., D.Sc, F.R.SS.L. & E., F.L.S., F.G.S., ETC. Regius Professor of Natural History in the University of EAiiiburgh, And Director of the Civilian Scientific Staff of the ' Challenger' Exploring Expedition. IN TWO VOLUMES. VOLUME I. jgnMiefctn bg §.u%rhg of % Iorbs flmrarassimura of % JPmrralis. $xmbmi: MACMILLAN AND CO. 1877. TO THE RIGHT HONOURABLE G. J. GOSCHEN, M.P., UNDEE WHOSE ADMINISTRATION, AS FIEST LOED OF THE ADMIRALTY, THE 'CHALLENGER' EXPEDITION WAS OBGANIZED, %\m Mttnws AEE EESPEGTFULLY DEDICATED, AS A MAEK OF WAEM APPEECIATION OF THE EFFECTIVE INTEEEST WHICH HE HAS TAKEN IN THE ADVANCEMENT OP SCIENCE, AND OF SCIENTIFIC INSTEUCTION IN THE NAVY. EDINBURGH, January 2nd, 1877. "^ PKEEACE. THESE two volumes consist chiefly of an abstract of the less technical portions of my own journal for the first year of the voyage of the 'Challenger' (1873), and the early part of the fourth year (1876), when she again traversed the Atlantic on her way home. With these 1 have incorporated some of the more novel results of the observations of my colleagues, and I have added, usually in the form of Appendices, such Meteorological Tables, Tables of depths and of sea-temperatures, and Tables, of specific-gravity de terminations, as shall be sufficient to place in the hands of our fellow-workers in the field of Physical Geography at all events an abstract of the data on which our conclusions and speculations are founded, and enable them to judge for themselves. I had much hesitation in attempting to prepare these volumes for publication, at sea; for the last four years the duties of each day have nearly fully occupied our time: our minds have been continually distracted by new impressions and by the necessity X PREFACE. of devoting undivided attention to new objects of interest; ship-life is generally unfavourable to steady- work, and during a great part of the time the motion of the ship makes it impossible to have even the limited space at one's command in his cabin, littered with papers and journals and memoranda in the orderly confusion which is inseparable from comfort able literary work. Although there was a reference library on board the ' Challenger,' excellent under the circumstances, it was of course by no means complete enough to enable us to go with safety into matters of detail. Still, notwithstanding these diffi culties, it seemed to me so desirable that a sketch of our proceedings and of the more important results of the Expedition should be made public at as early a date as possible, that I determined to make the attempt. At first I hoped that it might have been possible to make the publication of the journal almost keep pace with the voyage, or that at all events the rough results of one year's work might have been published during the next, and accordingly a great part of the first volume was written and put into type during the year 1874. I found, however, 'that this was imprac ticable ; the uncertainty of communication became greater as the voyage proceeded; and inevitable delays having occurred, further observations con stantly made it necessary to modify previously formed opinions, or desirable to strengthen them by additional evidence. We arrived in England on the 24th of May, 1876, PREFACE. xi with the rough journal of the cruise in a sense complete, but not in a form for publication. Erom the amount of work thrown upon my hands in getting the collections into order, and having arrange ments made for the working out of the scientific results, the difficulties in the way were even greater than they had been on ship-board; and now, nearly a year after our return, the first two volumes only are completed. In a former volume1 I have given a general his tory of deep-sea investigations. I have described with some minuteness the appliances and methods employed during the preliminary cruises of the ' Lightning' and ' Porcupine' in ascertaining the exact depth, in taking bottom and intermediate temperatures, and in determining the distribution of the deep-sea fauna by means of the dredge; and I have stated the general conclusions on various questions to which we were at that time led by the study and generalization of our results. Although the additional experience which we have now gained has caused me to alter my views on one or two im portant points, I adhere in the main to the opinions and statements contained in that book, and to save unnecessary repetition I shall regard 'The Depths of the Sea' as a general introduction to the series of volumes giving an outline of the ' Challenger' Circumnavigating Expedition. This last undertaking was on a very different scale from the trial cruises of the gun-boats, and 1 ' The Depths of the Sea.' Second Edition. Macmillan and Co. x[[ PREFACE. the first chapter is occupied with the description of the much more complete arrangements for scientific work on board the ' Challenger.' After the termination of the cruise of the ' Porcu pine ' I had a very strong conviction that the forami- nifera of the genera Globigerina, Orbulina, and JPul- vinulina, which are chiefly concerned in forming the modem chalk, lived on the bottom ; our later obser vations have, however, satisfied me that they never live on the bottom ; but that they inhabit the surface, and the water to a limited depth beneath it. My general views with regard to ocean-circulation remain unaltered; I think, however, that we have now good reason to believe that the indraught of water at a low temperature into the Atlantic and Pacific—gulfs as we may almost call them,—from the Southern Sea, is to a great extent due to an excess of precipitation over evaporation in the : water-hemi sphere ' and a corresponding excess of evaporation over precipitation in the ' land-hemisphere ;' that in fact a part of the circuit of general ocean circulation passes through the atmosphere. The Zoological descriptions and determinations both in ' The Depths of the Sea' and in this pre liminary sketch of the proceedings of the ' Chal lenger' must be regarded as to a certain extent provisional; some of the more remarkable and novel forms have been selected for illustration to give a general idea of the fades of deep-sea life, but the amount of new material is very large, and it will take some years of the patient work of many hands, PREFACE. Xlll with full access to libraries and F c. R. 8.5 = _ collections, to bring it into ^&£— 23 order. —23- —p7~ 22 80 As in 'The Depths of the -— ES! 21 Sea,' the metrical system of 20 measurement and the centi 75 _j^ = = 19 grade thermometer scale are -a-a- 18 ^t employed in these volumes. In — case the centigrade notation 70 -S4-I- iz^z 17 =9^ 16 should not be familiar to all ;= —1-9- IS my readers, I introduce a f>S =13= • 14 comparative scale, embodying —17- those of Eahrenheit, Celsius —TK~ 15 60 La_ 12 (Centigrade), and Pdaumur, for — • reference.* II 55 =RT With few exceptions the illus — ^= 10 —12- trations are from drawings by 9 H : Mr. J. J. Wild; and as in the 50 =ls= I^H S former volume I have to give =9= 7 my best thanks to Mr. Cooper for —fi— 46 —— 6 the excellent manner in which =EZ= 5 Mr. Wild's beautiful drawings ft - =s= 4 have been rendered on the 40 ==~ —4— 3 = ' wood. —a»— 2 After the first chapters of 35 —2— . J 1 these volumes were written -—•— ;33e many changes took place in our E3SE: : -=ir! : 1 staff. Captain Nares, P.R.S., M) :m^= •=•2= 2 was recalled at the end of the == ^3 * 1° Fahrenheit = 0-55'J C = 0'44° R. ?5 == 3 0 -~4 _^=^= I 'Centigrade = 0-80° E, = 1-80° F. _4 .1° Reaumur = 1"25° 0. = 2-25° F. ZZ3S xiv PREFACE. second year, to take command of the Arctic Expedi tion. This was a heavy blow to the 'Challenger.' Captain Nares, from his experience as a surveying officer, was eminently fitted to direct the executive in such an undertaking, and the deep interest which he took in every branch of our investigations, and the intelligent knowledge which he possessed of their scope and objects, were the best possible guarantee for the various operations being thoroughly and conscien tiously carried out. We were indeed most fortunate in the choice of a successor to Captain Nares, for Captain Erank Thomson, although identified with another branch of the service, and lying under the further disadvantage of wanting the experience in the new field of research which we had laboriously gained during the two previous years, showed himself in every way anxious to carry out the system initiated by Captain Nares, and to adopt any reasonable suggestion for the more complete performance of our task. I think nearly all of us, naval and civilian, wildly volunteered to follow oar old Captain—to the Pole or anywhere else.