F 9. fee oe--0--fe—e: oe } i; 4 s a Ao Wey . ---@-----' ; : Be Paes ; ke ee : a 2 2 ee | CORNELL UNIVERSITY LIBRARY FROM ig Cornell University Library The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924024771556 THE DEPTHS OF THE SEA. THE DEPTHS OF THE SEA. AN ACCOUNT OF THE GENERAL RESULTS OF THE DREDGING CRUISES OF H.M.8S. ‘PORCUPINE’ AND ‘LIGHTNING DURING THE SUMMERS OF 1868, 1869, AND 1870, UNDER THE SCIENTIFIC DIRECTION OF DR. CARPENTER, F.R.S., J. GWYN JEFFREYS, F-.R.S., AND DR. WYVILLE THOMSON, F.R.S. BY C WYVILLE THOMSON, LLD., D.8c., F.R.SS8. L.&E., F-LS., F.GS., Ero. Regius Professor of Natural History in the University of Edinburgh, And Director of the Civilian Scientific Staff of the ‘Challenger’ Exploring Expedition. WITH NUMEROUS ILLUSTRATIONS AND MAPS. London : MACMILLAN AND CQO. 1873. LONDON : R, CLAY, SONS, AND TAYLOR, PRINTERS, BREAD STREET HILL. TO MADAME HOLTEN This Volume 18 dedicated, IN GRATEFUL REMEMBRANCE OF THE PLEASANT TIMES SPENT BY HIMSELF AND HIS COMRADES AT THE GOVERNOR'S HOUSE IN THORSHAVN, BY THE AUTHOR. PREFACE. Av the close of the Deep-sea Dredging Expeditions which had been undertaken by the Admiralty at the instance of the Council of the Royal Society during the years 1868, 1869, and 1870, it was thought right that those who had been entrusted with their scien- tific direction should, in addition to their official reports, lay before the general public some account of their proceedings with the objects ;—first, of show- ing, if possible, that the value of the additions which had been made to human knowledge justified the liberality of Government in acceding to the request of the Council of the Royal Society, and placing means at their disposal to carry out the desired researches; and, secondly, of giving such a popular outline of the remarkable results of our work as might stimulate general interest, and induce those who have the proclivities and the opportunity, to penetrate farther into the new and strange region on whose borders we have had the good fortune to have been among the first to encroach. vill PREFACE. It was originally intended that the general account should have been a joint production, each of us con- tributing his part. There were difficulties, however, in the way of this arrangement. We were all fully occupied with other matters, and the amount of communication and correspondence between us, re- quired to carry out the plan of joint authorship, seemed likely to prove a cumbrous complication. It was therefore decided that quoad the popular exposition I should take upon myself the office of ‘reporter,’ and thus it comes about that I am indi- vidually and solely responsible for the opinions and statements contained in this book, save where they are included within quotation marks, or their sources otherwise acknowledged. Since we began these deep-sea investigations, inquiries have come in from all quarters, both at home and abroad, as to the implements and methods. which we employ. To supply the desired informa- tion, I have described, in detail, the processes both of sounding and dredging; and I hope that the special chapters on these matters—the result of considerable experience—may be found useful to beginners. I pretend to no special knowledge of physics, and I should have greatly preferred confining myself to the domain of Biology, my own proper province; but certain physical questions raised during our late explorations have so great importance in relation to PREFACE. ix the distribution of living beings, and have of late been brought into so great prominence by Dr. Car- penter, that it has been impossible for me to avoid giving my earnest consideration to their general bearings on Physical Geography, and forming decided opinions, which, I regret to say, do not altogether coincide with those of Dr. Carpenter. The chief points on which my friend and I ‘agree to differ’ are discussed in the chapter on the Gulf-stream. It was at first my intention that appendices should be added to the different chapters, containing lists and scientific descriptions of the animal forms which were observed. This it was found impossible to accomplish, chiefly on account of the large number of undescribed species which were placed in the hands of the experts who undertook the examination of the several groups. I am not sure that, even if it had been possible to furnish them in time, such lists would have been altogether an appropriate addition to what is intended merely as a popular preliminary sketch. The metrical system of measurement, and the centigrade thermometer scale, have been adopted throughout the volume. The metrical system is pro- bably familiar to most of my readers. In case the centigrade notation, which comes in very frequently owing to the frequent discussion of questions of the distribution of temperature, should not be equally familiar, a comparative scale, embodying those of xX 85 -— {== 23 22 80 Se 2! 20 75 === 19 a rr) 16 = 65 ———= ————— == ; 13 60 —= == |2 ————T 55 hs} io = = 9 —— = 7 45 = 6 = 3 Sj | 4. 40 =——| ————— — ———— 2 35 —SS —— I === -e— 50 = -1 = ——S -2 —————— a ==—— ie e=5— 4 Allman, F PREFACE. Fahrenheit, Celsius, and Réau- mur, is introduced for com-— parison. My various sources of infor- mation, and the friendly as- sistance I have received on all hands during the progress of our work, are acknowledged, so far as possible, in the text. I need here only renew my thanks to Staff-Commander May and the officers of the ‘Lightning,’ and Captain Cal- ver and the officers of the ‘Porcupine,’ without whose hearty sympathy and co-ope- ration our task could never have been satisfactorily accom- plished; to my colleagues, Dr. Carpenter, F.R.S., and Mr. Gwyn Jeffreys, F.R.S., who have cordially assisted me in every way in their power; and to the naturalists into whose hands the animals of various classes were placed for descrip- tion and study,—the Rev. A. Merle Norman, Professor Kél- liker, Dr. Carter, F.R.S., Dr. .R.S., Professor Martin Duncan, F.R.N., PREFACE. xi and Dr. M‘Intosh, for information courteously supplied. The whole of the illustrations in the book—with the exception of the vignettes of Féroe scenery for which 1 am indebted to the accomplished pencil of Madame Holten—are by my friend Mr. J. J. Wild. I need scarcely thank him for the admirable way in which he has accomplished his task, for every figure was with him a labour of love, and I almost envy him the gratification he must feel in the result. To Mr. J. D. Cooper I owe my sincere thanks for the singularly faithful and artistic rendering of Mr. Wild’s beautiful drawings on the wood-blocks. On the return of the ‘ Porcupine’ from her last cruise, so much interest was felt in the bearings of the new discoveries upon important biological geo-- logical and physical problems, that a representation was made to Government by the Council of the Royal Society, urging the despatch of an expedition to traverse the great ocean basins, and take an out- line survey of the vast new field of research—the bottom of the sea. Rear-Admiral Richards, C.B., F.R.S., the Hydro- vrapher to the Navy, warmly supported the pro- posal, and while I am writing a noble ship is lying at Sheerness equipped for scientific research under his wise and liberal directions, as no ship of any nation was ever equipped before. Xi PREFACE. The scientific staff of the ‘Challenger’ are well aware that for some time to come their réle is to ‘work and not to talk; but now, on the eve of depar- ture, I think it is only right to take this opportunity of saying that nothing has been left undone by the Government to ensure the success of the undertaking, and that dire misfortune only ought to prevent our furnishing a valuable return. C. WryviLtLE THomMson. EpINBURGH, December 2nd, 1872. 7| Slattaretindur 2b} CONTENTS. CHAPTER I. INTRODUCTION. The Question of a Bathymetrical Limit to Life—The general Laws which regulate the Geographical Distribution of Living Beings.—Professor Edward Forbes’ Investigations and Views.—Specific Centres.—Repre- sentative Species.—Zoological Provinces.—Bearings of a Doctrine of Evolution upon the Idea of a ‘Species, and of the Laws of Distribution. —The Circumstances most likely to affect Life at great Depths : Pres- sure, Temperature, and Absence of Light ... ... ... ... ..., Pagel CHAPTER II. THE CRUISE OF THE ‘LIGHTNING.’ Proposal to investigate the Conditions of the Bottom of the Sea.—Sugges- tions and Anticipations.—Correspondence between the Council of the Royal Society and the Admiralty.—Departure from Stornoway.—The Féroe Islands.—Singular Temperature Results in the Féroe Channel.— Life abundant at all Depths.—Brisinga coronata.—Holtenia carpenteri. —General Results of the Expedition ... ... 2. 1. ... Page 49 AppenpIx A.—Particulars of Depth, Temperature, and Position at the various Dredging Stations of H.M.S. ‘ Lightning,’ in the Summer of 1868 ; the Temperatures corrected for Pressure ... ... ... Page 81 CHAPTER III. THE CRUISES OF THE ‘ PORCUPINE,’ The Equipment of the Vessel.—The first Cruise, under the direction of Mr. Gwyn Jeffreys, off the West Coast of Ireland and in the Channel between Scotland and Rockall.—Dredging carried down to 1,470 fathoms. XIV CONTENTS. —Change of Arrangements.—Second Cruise ; to the Bay of Biscay.— Dredging successful at 2,435 fathoms.—Third Cruise ; in the Channel between Fxroe and Shetland.—The Fauna of the ‘Cold Area.’ Page 82 Appenpix A.—Official Documents and Official Accounts of preliminary Proceedings in connection with the Explorations in H.M. Surveying- vessel ‘Porcupine, during the Summer of 1869 ... ... ... Page 133 Apprnpix B.—Particulars of Depth, Temperature, and Position at the various Dredging Stations of H.M.S8. ‘Porcupine, in the Summer of 1869) sy. ae Gee ge Fed gee: Re eee at aes a ose SPage 149 CHAPTER IV. THE CRUISES OF THE ‘PORCUPINE’ (continued). From Shetland to Stornoway.—Phosphorescence.—The Echinothuride.— The Fauna of the ‘Warm Area.’—End of the Cruise of 1869.—Arrange- ments for the Expedition of 1870.—From England to Gibraltar.— Peculiar Conditions of the Mediterranean.—Return to Cowes. Page 145 Appendix A.—Extracts from the Minutes of Council of the Royal Society, and other official Documents referring to the Cruise of H.M.S. ‘ Porcu- pine’ during the Summer of 1870 2... Page 197 ApPeNDIx B.—Particulars of Depth, Temperature, and Position at the various Dredging-stations of H.M.S. ‘Porcupine’ in the Summer of THO wisn cin: shaw Shetek Gb days gS. she onal. gee » aces Page 202 CHAPTER V. DEEP-SEA SOUNDING. The ordinary Sounding-lead for moderate Depths.—Liable to Error when employed in Deep Water.—Early Deep Soundings unreliable.—Improved Methods of Sounding.—The Cup-lead.— Brooke’s Sounding Instrument.—. The ‘Bull-dog ;’ Fitzgerald’s ; the ‘ Hydra.’—Sounding from the ‘ Poreu- pine.’—The Contour of the Bed of the North Atlantic .. Page 205 CHAPTER VI. DEEP-SEA DREDGING. The Naturalist’s Dredge.—O. F. Miiller.—Ball’s Dredge.—Dredging at moderate Depths.—The Dredge-rope.—Dredging in Deep Water.—The ‘Hempen tangles.’—Dredging on board the ‘ Porcupine.’—The Sieves.— CONTENTS. XV The Dredger’s Note-book.—The Dredging Committee of the British Association.—Dredging on the Coast of Britain.—Dredging abroad.— History of the Progress of Kuowledge of the Abyssal Fauna. Page 236 Aprenpix A.—One of the Dredging Papers issued by the British Associa- tion Committee, filled up by Mr. MacAndrew ws ax vee —————— wo soe a 22 nn cael os Eee ——4ng- 6 {ie = —— =5 2068 6 99 =o, 77 ws a ef se v ae 234 fay/ee Pages WG _ ® oy @ fe a 68 . ie ae 67 2 wp At a, 75 fae av SHETLAND.I8 pe ee PT Dol og “i < ae mn _#4, PE en H G 0 | . ” c a 33 94 46 16 is 7d 7] DFurl Yo E 20 63 2 a 9 She: 24 36, yo 7b a a Lae g ale eee ibe ORKNEY. I? s eek: fi o : ; nme) Wt a 4 oR $l gg! G0 Soi 6a an sd Pontos BL? 38 ‘i F BB 5 35 go is 4 P 38 AR é ‘ts 30 a 80 J ae NORTH SEA np 0 36 oe vA Q 0° V CHAP. U1] THE CRUISES OF THE ‘PORCUPINE? 107 with twelve blue-jacketed Shetlanders sitting like statues, their white oars glittering in the sun. The Governor looked with the critical eye of a sailor at the two boats,—he still spoke lovingly of the ‘ Maid of Féroe,’ but I suppose he saw that, as ‘Tennyson says, ‘we were all of us Danes;’ and the question of a trial of strength lapsed by mutual consent ! We were obliged to remain a few days at Thorshavn replenishing in various ways, and while there we were very anxious to have had an opportunity of seeing Myling Head—a magnificent cliff at the north-western point of Stroma, which falls perpendicularly, even slightly overhanging its base, from a height of upwards of 2,000 feet into the sea. The tide runs. among and round these islands like a mill-race, and the Governor told us that if we started with the morning flood, and our vessel kept pace with the tide, we might make the circuit of the island, passing under Myling, and returning to Thorshavn in six hours. If we did not carry the tide with us, it became a matter of dif- ficulty only to be achieved at considerable expense both of fuel and time. We found that high water would occur on the fol- lowing Monday, Aug. 28, at 4 o’clock in the morning ; and as the weather was brilliant up to the evening of Sunday—unusually brilliant for those regions—we made all our arrangements in high hope of a pleasant trip, as we had persuaded our kind host and hostess to accompany us. With the first dawn of Monday morning it was blowing and pouring, and we were obliged to defer our visit to the celebrated headland to some possible future opportunity. The next morning was fine again, and we left 108 THE DEPTHS OF THE SEA. (cua. U1. Thorshavn about noon, steaming east by south, so as to cross the deep channel between Feroe and Shetland. Our first two stations were on the Féroe plateau, at depths a little over a hundred fathoms, but the third sounding, taken in the evening of the 24th at a depth of 317 fathoms, gave a bottom temperature of —0°9 C.; we were therefore once more in the cold current. Having kept the same course under easy steam during the night, we took a sounding next morning, lat. 61° 21’ N., long. 8° 44/ W., at a depth of 640 fathoms, with a bottom temperature of — 1°1C. A haul of the dredge brought up rolled pebbles and Fic. 12.—Pourtalesia jefreysi, Wyv1LLE Tuomson. Slightly enlarged.l (No. 64.) fine gravel with few animal forms, but among them one of extraordinary interest, a large specimen of a fine species of the genus Pouwrtalesia, a heart-urchin, one of whose congeners had been discovered by M. de Pourtales in the gulf-stream explorations off the American coast, and a second by Mr. Gwyn Jeffreys near Rockall. The present example (Fig. 12) was much larger than either of those previously dredged, and it appeared to be specifically distinct. 1 Thave the pleasure of dedicating this interesting species to our accomplished culleague, J. Gwyn Jeffreys, F.R.S. CHAP. III.] THE CRUISES OF THE ‘ PORCUPINE’ 109 The shell is singularly unlike that of any other known living echinoderm. It is about two inches in length, almost cylindrical, ending posteriorly in a blunt rostrum, and the anterior extremity is truncated. The surface of the shell is covered with short spatulate spines, and near the anterior end there is a kind of fringe of long thin cylindrical spines, especi- ally congregated on the upper surface. The mouth is at the bottom of a deep anterior and inferior groove, and the excretory opening is at the bottom of a pit on the dorsal surface, above the terminal rostrum. The arrangement of the ambulacra is most peculiar. The four ovarial openings and the madreporic tubercle are on the dorsal surface, just above the truncated anterior end at the base of which the mouth lies, and the three ambulacral vessels of the ‘trivium’ take a short course from the oral vascular ring, one along the centre of the anterior face, and the other two round its edges to meet in a ring surrounding the ovarial openings. The two vessels of the ‘bivium’ have a very singular course. They run back into the great posterior prolongation of the shell, on the sides of which they form long loops, sending conical water-feet through single pores in long double lines of somewhat irregularly-formed ambulacral plates, which finally converge in a point a considerable distance behind the point of convergence of the three am- bulacra of the bivium. Between these two points of convergence, which are both on the middle line of the back, several plates are intercalated. We have thus the three anterior ambulacra ending in their ocular plates, meeting at one point, where there are likewise four genital plates, and the madreporic 110 TUE DEPTHS OF THE SEA. (CHAP, 111, tubercle; and the two posterior ambulacra, with their ocular plates, meeting at another point and forming a kind of secondary apex. The fifth genital plate is obsolete. The specially interesting point is that, while we had so far as we were aware no living representative of this peculiar arrangement of what is called ‘disjunct’ ambulacra, we have long ~been well acquainted with a fossil family, the Dysaséteride, possessing this character. Many species of the genera Dysaster, Acassiz, Collyrites, DESMOULINS, Metaporhinus, Micuetiy, and Grasia, MICHELIN, are found from the lower oolite to the white chalk, but there the family had previously been supposed to have become extinct. The next attempt was one of our very few entirely unsuccessful hauls, the dredge coming up empty. This we attributed to an increase of wind and swell, and consequent drift on the vessel, which seemed to have prevented the dredge from reaching the ground. We devoted the morning to a series of temperature soundings at intervals of 50 fathoms from the surface to the bottom, and this we accomplished in a very satisfactory manner, with results which will be fully discussed hereafter. After a rapid descent for the first 50 fathoms the next 150 fathoms maintained a high and a tolerably equable temperature, and there was then a rapid fall between 200 and 300 fathoms, the thermometer at the greater depth indi- cating 0°C. From 300 fathoms to the bottom the temperature fell little more than a degree. “‘ Thus the entire mass of water in this channel is nearly equally divided into an upper and lower stratum, the lower being an Arctic stream of nearly 2,000 feet caar. ut.) THE CRUISES OF THE‘ PORCUPINE! 17 deep, flowing in a south-westerly direction, beneath an upper stratum of comparatively warm water moving slowly towards the north-east; the lower | half of the latter, however, having its temperature considerably modified by intermixture with the stratum over which it lies.”’? Our next few dredgings were on the Shetland plateau, in depths under 100 fathoms, and over ground already carefully worked by our colleague Mr. Gwyn Jeffreys. We got few novelties, but owing to our very effective dredging appliances we took some of the ‘ Haaf’ rarities, such as Fusus nor- vegicus, CHEMN.; Musus berniciensis, Kine; Pleuro- toma carinatum, BIvona; in considerable numbers. The hempen tangles stood us in good stead with the echinoderms. On one occasion the dredge brought up at a single haul, in the bag and on the tangles, cer- tainly not less than 20,000 examples of the pretty little urchin, Echinus norvegicus, D. and K. On the 28th of August we anchored in Lerwick Harbour. We remained at Lerwick several days taking in necessary supplies, looking at the geology and the many remarkable antiquities of the neigh- bourhood, and ransacking the haberdashers’ shops for those delicate fleecy fabrics of wool which imitate in a scarcely grosser material, and with almost equal delicacy of design, the fretted skeletons of Holtenia, Euplectella, and Aphrocallistes. In this earlier part of the cruise nearly all the dredgings had been confined to the cold area, and 1 Dr. Carpenter, in “ Preliminary Report on the Scientific Ex plora- tion of the Deep Sea, 1869.” (Proceedings of the Royal Society, vol. xvi. p. 441.) 112 THE DEPTHS OF THE SEA. {cHAr. 111, over that region we had found a great uniformity of conditions. As already mentioned, the average bottom temperature throughout was a little below the freezing- point of fresh water, and it sometimes fell to nearly 2° C. below the zero of the centigrade scale. The bottom was uniformly gravel and clay, the gravel on the Scottish side of the channel consisting chiefly of the débris of the laurentian gneiss and the other metamorphic rocks of the North of Scotland, and the devonian beds of Caithness and Orkney. On the Féroe side of the channel, ou the other hand, the pebbles were chiefly basaltic. This difference shows itself very markedly in the colour and composition of the tubes of annelids, and the tests of sundry fora- minifera. The pebbles are all rounded, and the varying size of the pebbles and roughness of the gravel in different places give evidence of a certain amount of movement of material along the bottom. There seems to be but little doubt, from the direction of the series of depressions in the isothermal lines of the region (Pl. 7), that there is a direct move- ment of cold water from the Spitzbergen Sea into the North Sea, and that a branch of this cold indraught passes into the Féroe Channel. The fauna of the cold area is certainly characteristic, although many of its most marked species are common to the deep water of the warm area whenever the temperature sinks below 2° or 3° C. Over a considerable district in the Féroe Channel there is a large quantity of a sponge which is pro- bably identical with Cladorhiza abyssicola, SARs, dredged by G. O. Sars in deep water off the Loffoten Islands. This sponge forms a kind of CHAP. III.] THE CRUISES OF THE ‘ PORCUPINE’ 118 bush or shrub, which appears to clothe the bottom in some places over a large area like heather on a moor. There are at least three species. In one the branches are strict and rigid; while in another the arrangement is more lax, side branches coming off from a flexible centrai rachis like the barbs from the shaft of an ostrich feather. The branches seem in some cases to be from 50 to 80 centimetres in height, and the stems near the base are 2 to 3 centimetres in diameter. The stem and branches consist of a firm central axis, semi-transparent and of a peculiar yellowish green colour; composed of a continuous horny substance filled with masses of needle-shaped spicules arranged longitudinally in dense sheaves. This axis is overlaid by a soft bark of sponge sub- stance supported by needle-shaped spicules, and full of the bihamate ‘spicules of the sarcode’ so charac- teristic of the genus Esperia and its allies. The crust is covered with pores, and rises here and there into papillee perforated by large oscula. This sponge appears to belong to a group allied to the Espe- riade, and perhaps even more closely allied to some of the fossil branching forms whose remains are so abundant in some beds of the cretaceous period. A still finer species of the same group was dredged by Mr. Gwyn Jeffreys in the first cruise of the following year. Another peculiar sponge (Fig. 18) is very abundant and of a large size. This form was admirably described by Professor Lovén—unaccountably under the name of Hyalonema boreale. It is certainly very far from Hyalonema. It is more nearly allied to Tethya, for the body of the sponge must certainly be referred to I 114 THE DEPTHS OF THE SEA. [cHap. 1, the corticate type, though it differs from all the other known members of the order in being supported on a long symmetrical stalk formed, as Professor Lovén has shown, of Sheaves of short spicules bound together Fic. 13.—Stylocordyla boreulis, Lovin (Sp.). Natural size. (No. 64.) by horny cement. A tuft of delicate fibres fixes the base of the stem in its position. Professor Oscar Schmidt, in his “Outline of the Sponge Fauna of the Atlantic,” refers this form to his genus Cometella, cHaP. 1!.] THE CRUISES OF THE ‘ PORCUPINE, 115 and this he associates with Suberites, Tethya greatly restricted, and one or two other generic groups, to form a family the Suberitidine, a part of the old order Corticatse, which order he now proposes to dismember. I doubt if this arrangement will hold good, for the silicious sponges whose skeleton con- sists mainly of radiating sheaves of long spicules, form a conspicuous and natural assemblage. Stylo- cordyla is evidently nearly related in habit and general character to the Mediterranean stalked sponge figured by Schmidt under the name of Tetilla euplocamos.’ Foraminifera are not very abundant in the cold area, though here and there in isolated patches large numbers of large and remarkable forms came up on the ‘hempen tangles.’ These were principally of the Arenaceus type. On one occasion, at Station 51, one of the intermediate dredgings between the warm area and the cold, the tangles brought up a multitude of tubes three-quarters of an inch to an inch long, composed of sand-grains cemented together, and with a slight appearance externally of beading, as if they were divided into segments. During the ‘Lightning’ excursion the year before, on the middle bank along with the specimens of Lerebratula cranium, we had found in abundance a sandy Litwola with very much the same appearance, except that at one end the Litwole had a promi- nent mouth, and on breaking them open this mouth was repeated, definitely moulded of peculiarly Die Spongien der Kiiste von Algier. Von Dr. Oscar Schmidt Professor der Zoologie und vergleichenden Anatomie, Director des a . * Tandschaftlichen zoologischen Museums zu (tratz. Lei pzig, 1868. 1 2 116 THE DEPTHS OF THE SEA. [cHAP. 111, coloured sand grains, for every chamber of the series into which the test was divided. The new form, how- ever, was found not to be divided into chambers, but to have its cavity continuous throughout, “though traversed in every part of its length by irregular processes, built up partly of sand-grains and partly of sponge-spicules,”’ resembling those described by Dr. Carpenter in the gigantic fossil form Parkeria.* One extremity of this chamber is arched over, spaces being left between the agglutinated sand-grains, through which it appears that the gelatinous being within com- municates with the outer world by protruding its sarcode processes. The other end was so constantly broken off, leaving a rough fracture, that Dr. Carpenter was inclined to believe that this form to which he gave the generic name of Botellina, grew attached to the bottom or to some foreign body. The cold area teems with echinoderms. In the channel north and west of Shetland, we added to the fauna of the British area besides a large number of species new to science, nearly every one of the forms described by the Scandinavian naturalists as inhabit- ing the seas of Norway and Greenland. In comparatively shallow water Cidaris hystria was most abundant, and of large size. The large form of Lchinus flemingii, BALL, was rare; but every haul at all depths brought up some variety or other which was referred with doubt to EZ elegans, D. and K., to one or other form of EF. norvegicus, D. and K., or to #. rarituberculatus, G.O. Sars; and although it may, perhaps, be necessary still to describe all these which certainly in their extreme forms present very 1 Philosophical Transactions, 1869, p. 806. cHAP. IIL] THE CRUISES OF THE ‘ PORCUPINE, 117 marked differences as distinct species, after having gone over some thousands of them—some brought up in nearly every haul of the dredge from Féroe to Gibraltar—I am inclined to suspect that they may be all varieties of Echinus flemingit. I have already alluded to the countless myriads in which the small form of E. norvegicus, D. and K., 15 mm. in diameter, swarms on the ‘ Haaf’ fishing banks. These little urchins are mature so far as the develop- ment of their generative products is concerned ; and I suspect from the abundance of three sizes, that they attain their full size in two years and a half or three years; but in colouring, in sculpture, and in the form of the pedicellarize, I do not see any character to distinguish them from a form four times the size, common in deep water off the coast of Ireland; nor, again, can I distinguish these last by any definite character which one would regard as of specific value from the shallow water form of Echinus flemingii, as large as the ordinary varieties of E. sphera. The Shetland variety of Equus caballus is certainly not more than one-fourth the size of an ordinary London dray-horse, and I do not know that there is any good reason why there should not be a pony form of an urchin as well as of a horse. Professor Alexander Agassiz! has discovered that the Florida species of Lichinocyamus is nothing more than the young of a common Florida clypeas- troid, Stolonoclypus prostratus, AG., and he sug- gests the possibility of our Echnocyamus ee en Leskz, being one of these stunted ‘pony ’ varieties, or undeveloped young, either of the American Stolo- 1 Bulletin of the Museum of Comparative Zoology, No. 9, p. 291, 118 THE DEPTHS OF THE SEA. [cwap. 111. noclypus, the pluteus ‘pseudembryo’ having been carried along and distributed by the gulf-stream, or of some European deep-water clypeastroid hitherto unknown. Yhe three so-called species of the genus Tozo- pneustes of the cold area must, I fear, submit to fusion. TZ. pictus, Norman, and TZ. pallidus, G. ©. Sars, are certainly varieties of TZ. drobachi- ensis, O. F. MULLER. The young of Brissopsis lyrifera, FORBES, were abundant at all depths, but mature examples did not occur beyond 200 fathoms, and were larger and more abundant from 50 to 100 fathoms. TZ7i- pylus fragilis, D. and K., a rather scarce Scandinavian form, was added to the British fauna; several speci- mens having been taken, unfortunately usually crushed on account of its great delicacy, in the deeper and colder hauls. Magnificent specimens of the handsome heart-urchin, Spatangus raschi, were very abundant, associated in the same zone of depth with Cidaris. Star-fishes were very numerous, rare and new species sometimes actually crowding the hempen tangles. The two species of Brisinga, B. endeca- cnemos, ABSJ., and B. coronata, G. O. Sars, came up occasionally and were always regarded as prizes, although it was a matter of some difficulty to ex- tricate their spiny arms one after the other from the tangles; they were scarcely ever within the dredge. Salaster papposus, FORBES, apparently their nearest of kin though far removed, was represented abundantly by a very pretty deep-water variety, with ten arms about .forty millimetres across from tip to tip, OHAP. I11.] THE CRUISES OF THE ‘ PORCUPINE’ 119 of a bright orange-scarlet even at Station 64, at a depth of 640 fathoms; and we dredged abundantly S. furcifer, D. and K. (Fig. 14), previously known Fia, 14.—Solaster ureifer, Von Dusen and Koren, Natural size. (No. 55.) only in the Scandinavian seas. Pedicellaster typicus, Saks, occurred but sparingly, and more frequently the Fis, 15, —Korethraster hispidus, Wy VILLE Thomson, Dorsal aspect. Twice the natural size, (No. 57.) pretty biscuit-like Astrogonium granulare, MULLER and TRoscHEL. J. phrygianum, O. F. Mtu.Er, and 120 THE DEPTHS OF THE SEA. (CHAP, 10, Asteropsis pulvillus, O. F. MOLLER, were not met with beyond the 100-fathom line. A curious little group of cushion stars, hitherto supposed to be con- fined to high latitudes, were represented by Péeraster militaris, M. and T., and P. pulvillus, Sars, and by two forms new to science,—one, Korethraster his- pidus, sp. 0., with the whole of the upper surface covered with long free paxille like sable brushes (Fig. 15). Ranges of delicate spatulate spines border the Fis. 16,—Hymencster pellucidus, WyviLLE Tuomson. Ventral aspect. Natural size. (No. 59) ambulacral grooves. As in Pteraster, there is a double row of conical water feet. The other genus (Fig. 16) is perhaps even more remarkable. The star-fish is very flat, the dorsal surface covered with short paxil which support a membrane as in Pleraster. A row of spines fringing the ambulacral grooves is greatly lengthened and webbed, and the web running along the side of one arm meets and unites with the web CHAP. UL] THE CRUISES OF THE‘ PORCUPINE, 121 of the adjacent arm, so that the angles between the arms are entirely filled up by a delicate membrane stretched on and supported by spines, and the body ~ thus becomes regularly pentagonal. There is no trace on the ventral surface of the arms of the trans- verse ranges of membranous comb-like plates which are so characteristic in Péeraster. By far the most abundant and conspicuous forms among the star-fishes in deep water were the genera Astropecten and Archaster, and their allies. At one to two hundred fathoms the small form of Astro- pecten irregularis, A. acicularis of Norman, literally swarmed in some places, usually in company with the small form of ZLwidia savignii, M. and T., L. sarsi, D. and K. I feel no doubt that these two forms, A. acicularis and L. sarsii, are mere deep- water varieties of the forms which attain so much larger proportions in shallow water. Mr. Edward Waller took charge of Mr. Gwyn Jeffreys’ yacht during the summer of 1869, on a dredging cruise off the south coast of Ireland. He worked principally about the 100-fathom line and a little within it, and procured a magnificent series both of Astropecten and Luidia showing a gradual transition through all intermediate stages between the large and the small varieties. The cold area gave us Astropecten tenuispinus in great abundance and beauty. The tangles sometimes came up scarlet with them, and associated with this species a handsome new form of a peculiar leaden grey colour, and with paxillee arranged on the dorsal surface of the disk in the form of a rosette, or the petaloid ambulacra of a Clypeaster. Astropecten 122 THE DEPTHS OF THE SEA. (cHap. 111, arcticus, SARS, was met with sparingly in some of the deeper dredgings. The known northern species of Archaster were abundant and of large size; 4. parelli, D, and K., passing into comparatively shal- low water; and 4. andromeda abundant at greater depths. . Fig. 17.—Archaster bifrons, Wyvite Tuomson. Dorsal aspect. Three-fowths of the natural size. (No. 57.) At Stations 57 and 58, and at various others in the cold area we took many specimens of a fine Archaster (Fig. 17) with a double row of large square marginal plates giving the edges a thickened square-cut appearance like those of Ctenodiscus ; cuar.1u.] THE CRUISES OF THE ‘ PORCUPINE. 123 each marginal plate covered with miliary grains, and with a prominent rigid central spine. This is a large form, one of our most striking additions to the tale of known species. It measures 120 mm. from tip to tip of the arms across the disk. The colour is a rich cream, or various shades of light rose. Ctenodiscus crispatus occurred rarely and of rather small size, not more than 25 mm. across. Nearly every haul brought up small specimens of ( a aa _A s Sedtly [8 7] > can Ves y 2 xo uernsey Po ° Rous C.S Vinee Cibralta? Strait 31¢ 1\0 —————I ——— = ————————————S= ——— ——— Ss Los) tate + BNLGIUM FF 50 b o Parts U R So, 0 PK peer es \ 1 } “LipareD? arn cuar.tv.J) THE CRUISES OF THE ‘ PORCUPINE? 181 Geryon tridens, is a fine Norwegian species. With these are associated two forms of a more southern character, Inachus dorsettensis and Fbalia cranchi, which I should not have expected at so great a depth.” The echinoderms were a very northern group. They included Cidaris papillata, Echinus nor- vegicus and E. microstoma, the young of Brissopsis lyrifera, Astropecten arcticus, Archaster andromeda, and A. parellii, with a small specimen of Ophio- musium lymani, several examples of Ophiacantha spinulosa, and as usual one or two of the universally distributed Hehinocucumis typica. Dr. McIntosh, to whom the annelids were referred, notices as a species supposed to be specially northern, Thelepus coro- natus, Fas.; and Holtenia carpenteri, our familiar anchoring sponge, of all sizes and ages and in consider- able numbers, was entangled in the hempen ‘swabs.’ July 9th—The wind still too light for effective work. Dredged in 717 and 358 fathoms, the assem- blage of mollusca having the usual character of being to a great extent common to the recent fauna of the seas of Norway and to the pliocene fauna of Sicily and the Mediterranean. It included on this occasion Terebratella spitzbergensis, an arctic and Japanese form, Pecten vitreus, and P. aratus, Leda pernula, Trochus suturalis, Odostomia nitens, and Pleurotoma hispidulum. Among the echinoderms was a fine specimen of Brisinga endecacnemos, ABSJORNSEN, very markedly different from B. coronata, which was the form commonly met with in the north. The corals were represented by Amphihelia oculata and Desmophyllum erista-galli. Among the annelids were Pista cristata, O. F. MtLuER, and Trophonia glauca, 182 THE DEPTHS OF THE SEA. [OHAP. Iv. Matmcoren, both of them Arctic species. The 10th was Sunday, and the vessel lay-to, and on the 11th they dredged, still on the slope of the channel plateau, with nearly the same result as before, the fauna maintaining the same character. Mr. Gwyn Jeffreys was now anxious to get a haul or two in the very deep water off the mouth of the Bay of Biscay, which we had explored successfully in 1869. They therefore steamed southwards, going a considerable distance without dredging, as they were afraid of coming in contact with the cable between Brest and North America. When they got to their ground unfortunately bad weather set in, and they were obliged to make for Vigo. On Thurs- day, July 14th, they passed Cape Finisterre, and dredged in 81 fathoms about 9 miles from the Spanish coast. Along with a number of familiar forms, some of them with a wide northern exten- sion, they here took on the tangles two specimens, one young and one apparently mature, both con- siderably injured, of the singular Echinidean already mentioned, Calveria fenestrata. This is evidently not a rare form nor is it confined to very deep water ; it is rather remarkable that it should have escaped notice so long. On the 15th, they sounded in from 100 to 200 fathoms, about 40 miles from Vigo, and on the 16th took one or two hauls in Vigo Bay at a depth of 20 fathoms. This locality had already been well-nigh exhausted by Mr. McAndrew in 1849, and only a few additions were made to his list. They left Vigo on the 18th. I quote from Mr. Gwyn Jeffreys :— ““ Wednesday, July 20th.—Dredged all day with CHAP. Iv.] THE CRUISES OF THE ‘ PORCUPINE? 188 considerable success at depths from 3880 to 994 fathoms (Stations 14-16): the wind and sea had now gone down; and we took with the scoop-net a few living specimens of Clio cuspidata. The dredgings in 380 and 469 fathoms yielded among the mollusca Leda lucida (Norwegian and a Sicilian fossil), Avinus eumyarius (also Norwegian), Newra obesa (Spitz- bergen to the West of Ireland), Odostomia, n. sp., O. minuta (Mediterranean), and Cerithium, n. sp.; and among the echinoderms were Brisinga endecacnemos and Asteronyx lovéni. But the results of the dredg- ing in 994 fathoms were so extraordinary as to excite our utmost astonishment. It being late in the even- ing, the contents of the dredge could not be sifted and examined until daylight the next morning. We then saw a marvellous assemblage of shells, mostly dead, but comprising certain species which we had always considered as exclusively northern, and others which Mr. Jetfreys recognized as Sicilian tertiary fos- sils, while nearly 40 per cent. of the entire number of species were undescribed, and some of them repre- sented new genera. The following is an analysis of the mollusca perfect and fragmentary taken in this one haul :— ; ' Total ; Unde. Orders. | - Careaé Recent. Fossil. Seribed: Brachiopoda. . . . 1 1 — — Conchifera | 50 32 1 17 Solenoconchia . . . | 7 3 — 4 Gasteropoda. . : 113 42 23 48 Heteropoda . . : 1 1 — _— Pteropoda . a 14 12 — 2g | 186 91 24 71 184 THE DEPTHS OF THE SEA. [cHAP. Iv. The northern species above referred to are 34 in num- ber, and include Dacridium vitreum, Nucula pumila, Leda lucida, L. frigida, Verticordia abyssicola, Neera jugosa, N. obesa, Tectura fulva, Fissurisepta papillosa, Torellia vestita, Pleurotoma turricula, Admete viridula, Cylichna alba, Cylichna ovata, JEFFREYS n. sp., Bulla conulus, 8. Woop not Drsuayes (Coralline Crag), and Scaphander librarius. Leda lucida, Neera jugosa, Tectura fulva, Fissurisepta papillosa, Torellia vestita, as well as several other known species in this dredging, are also fossil in Sicily. Nearly all these shells, as well as a few small echinoderms, corals, and other organisms, had evidently been transported by some current to the spot where they were found ; and they must have formed a thick deposit similar to those of which many tertiary fossiliferous strata are composed. It seemed probable also that the deposit was partly caused by tidal action, because a fragment of Welam- pus myosotis (a littoral pulmonibranch) was mixed with deep-water and oceanic Pectinibranchiates and Lamellibranchiates. None of the shells were Miocene or of an older period. “This remarkable collection, of which not much more than one-half is known to conchologists, not- withstanding their assiduous labours, teaches us how much remains to be done before we can assume that the record of Marine Zoology is complete. Let us compare the vast expanse of the sea-bed in the North Atlantic with that small fringe of the coast on both sides of it which has yet been partially explored, and consider with reference to the dredging last men- tioned what are the prospects of our ever becoming acquainted with all the inhabitants of the deep cuap.tv.] THE CRUISES OF THE ‘ PORCUPINE’ 185 throughout the globe! We believe, however, that a thorough examination of the newer Tertiaries would materially assist us in the inquiry ; and such exami- nation is feasible and comparatively easy. Much good work has been done in this line; but although the researches of Brocchi, Bivona, Cantraine, Phi- lippi, Calcara, Costa, Aradas, Brugnone, Seguenza, and other able paleontologists in the south of Italy have extended over more than half a century, and are still energetically prosecuted, many species of molluscous shells are continually being discovered there, and have never been published. Besides the Mollusca in this dredging from 994 fathoms, Pro- fessor Duncan informs us that there are two new genera of corals, and Flabellum distinctum, which last he regards as identical with one from North Japan. It coincides with the discovery on the Lusitanian coasts of two Japanese species of a curious genus of Mollusea, Verticordia, both of which are fossil in Sicily and one of them in the Coralline Crag of Suffolk.” In the same dredging there are a number of very singular undescribed sponges, many of them recalling some of the most marked characters of one of the sections of Ventriculates. These will be referred to in a future chapter. On Thursday, the 2ist of July, dredging was carried on all day at depths from 600 to 1095 fathoms, lat. 39° 42’ N., long. 9°43’ W., with a bottom tempera- ture at 1095 fathoms of 4°3 C. and at 740 fathoms of 9°4C. The dredging was most successful; many of the new and peculiar mollusca of the last dredging were taken here alive, with several additional forms. 186 THE DEPTHS OF THE SEA. [CHAP. IV. Several undescribed crustaceans were added ;—a new species of the genus Cenocyathus among the corals, and a species of an unknown genus allied to Bathy- cyathus. Brisinga endecacnemos and some new ophi- urids were part of the treasures, but the greatest prize was a splendid Pentacrinus about a foot long, of which several specimens came up attached to the tan- gles. This northern Sea-lily, on which my friend Mr. Gwyn Jeffreys has bestowed the name Pentacrinus wyville-thomsont, will be described hereafter with some other equally interesting members of the same group. Cape Espichel was reached on the 25th. The weather was now, however, so rough that Captain Calver was obliged to take shelter in Setubal Bay. Professor Barboza de Bocage of Lisbon had given Mr. Gwyn Jeffreys a letter of introduction to the coastguard officer at Setubal, who knew the place where the deep-sea shark and the Hyalonema are taken by the fishermen, but the state of the weather prevented his taking advantage of it. Off Cape Espichel in 740 and 718 fathoms, with a temperature of 10°2 C., the mollusca were much the same as those from Station 16, but included Leda pusio, Limopsis pygmea (Sicilian fossils), and Verti- cordia acuticostata. The last-named species is in- teresting in a geological as well as a geographical point of view. It is fossil in the Coralline Crag and the Sicilian Pliocene beds, and it now lives in the Japanese archipelago. Mr. Jeffreys suggests a mode of accounting for the community of so many species to the eastern borders of the Atlantic basin and the Mediterranean, in which several Japanese brachi- opods and crustaceans are found, and the seas of CHAP. Iv.] THE CRUISES OF THE ‘PORCUPINE’ 187 Northern Asia, by supposing a migration through Fie. 36.—Chondrocladia virgata, WYVILLE THomsoy. One-half the natural size. (No. 33, Pl. V.) the Arctic Sea. We must know, however, much 188 THE DEPTHS OF THE SEA. [CHAP. Iv. more than we yet do of the extension both in time and space of the fauna of deep water before we can come to any certain conclusion on these questions. Dredging across the entrance of the Strait of Gib- raltar in 477, 651, and 554 fathoms, Stations 31, 32, and 88, with a bottom temperature of 10°3, 10°1, and 10°:0 respectively, many remarkable forms were dredged, including a very elegant sponge, apparently allied to, if not identical with, Oscar Schmidt’s, Caminus vulcani, and some beautiful forms of the Corallio-spongiz, which will be noticed in a future chapter. Station No. 31 yielded a sponge form which recalled the branching heather-like Cladorhiza of the cold area off Feroe. Chondrocladia virgata (Fig. 36) is a graceful branching organism from twenty to forty centimetres in height. A branching root of a cartilaginous consistence, formed of densely packed sheaves of needle-shaped spicules bound together by a structureless organic cement, attaches the sponge to some foreign body, and supports it in an upright position; and the same structure is continued as a solid axis into the main stem and the branches. The axis is made up of a set of very definite strands like the strands of a rope, arranged spirally, so as to present at first sight a strong resemblance to the whisp of Hyalonema ; but the strands are opaque, and break up under the point of a knife; and under the microscope they are found to consist of minute needle-like spicules closely felted together. The soft sponge substance spreads over the surface of the axis and rises into long curving conical processes, towards the end of which there is a dark greenish oval mass of granular sponge matter, and the outline of the omar. 1v.] THE CRUISES OF THE ‘ PORCUPINE? 189 cone is continued beyond this by a number of groups of needle-shaped spicules which surround a narrow oscular opening. All parts of the sponge are loaded with triple-toothed ‘bihamate’ spicules of the sarcode. On the 5th of August the ‘ Porcupine’ steamed into Tangier Bay, after ineffectually trying to dredge in 190 fathoms off Cape Spartel. In Tangier Bay two casts were taken at a depth of 35 fathoms. The fauna was chiefly British, with a few more southern forms. On the 6th of August Mr. Jeffreys went to Gib- raltar, and there yielded up the reins to Dr. Car- penter, going on to Sicily vid Malta, for the purpose of examining the newer tertiary formations in the south of Italy, and the collections of fossil shells at Catania, Messina, Palermo, and Naples, in connec- tion with the results of his cruise. On Monday, the 15th of August, Captain Calver, with Dr. Carpenter, who fortunately retained the services of Mr. Lindahl as assistant, in charge of the science department, steamed out into the middle of the Strait for the purpose of commencing a series of observations on the currents of the Strait of Gibraltar. These experiments, which at the time were not considered very satisfactory, were repeated and ex- tended in the summer of 1871 by Captain Nares, R.N., and Dr. Carpenter, in H.M.S. ‘Shearwater.’ Their curious results have been given in great detail by Dr. Carpenter in the Proceedings of the Royal Society of London, and by Captain Nares in a special report to the Admiralty. As it is my purpose to 190 THE DEPTHS OF THE SEA. [CHAP. IV. confine myself at present almost exclusively to the description of the phenomena of the deep water in the Atlantic so far as these have been worked out, I will not here repeat the narrative of the experiments in the Strait. I will, however, give a brief sketch of Dr. Carpenter’s cruise in the Mediterranean, as the remarkable phenomena connected with the distribu- tion of temperature and of animal life which he observed, illustrate while they contrast with the singularly different conditions which have been already described in the outer ocean. The first sounding in the basin of the Mediter- ranean was taken on the 16th of August, lat. 36° 0’ N., long. 4° 40’ W., at a depth of 586 fathoms, with a bottom of dark grey mud. The surface temperature was 23°6 C., and the bottom temperature 12°8 C., about three degrees higher than at the same depth in the ocean outside. A serial sounding was taken to determine the rate of the diminution of temperature, with the following curious result :— Surface . Se Bes R. Bosh ie te, BBPPGES 10 fathoms . . SS . 20°9 20, ee -_ . +6 30, . . : J a 40, ee a 16 50 =, Bose gh, ioe -aaroe as . « 16 100, ei a See 2 bs Tes 586, Hen Agm ts. oop tt ak . 12°8 Thus the temperature fell rapidly for the first 30 fathoms, more slowly for the next 20, from 50 to 100 lost only 3° C., and before reaching the depth of a hundred fathoms had attained its minimum tempera- CHAP. Iv.] THE CRUISES OF THE ‘ PORCUPINE? 191 ture, there being no further diminution to the bottom. This serial sounding and all the subsequent tempera- ture observations taken during the Mediterranean cruise showed that the trough of the Mediterranean from the depth of 100 fathoms downwards is filled with a mass of water at almost exactly the same temperature throughout, a temperature a little above or below 12°75 C. The following instances have been cited by Dr. Carpenter from the earlier observations in the Medi- terranean basin, to show the great uniformity of the bottom temperature for all depths :— Number | Depth Bottom Surface of in Tempera- | Tempera- Pasition. Station. | Pathoms. ture. ture. 41 730 | 13° 4C.| 23°: 6C.! Lat. 35°57’ N. | Long. 4°12’ W. 42 790 | 13°2 23-2 35 45 3 57 43 162 | 13°4 23 °8 85 24 3 1-30" 44 455 | 13-0 21-0 35 42 20” 3 00 30” 45 207 | 12°4 22-6 35 36 10” 2 29 30° 46 493 | 13-0 23° 0 35 29 1 56 AT 845 | 12°6 21°0 37 25°30” 1 10 30” At this last Station (No. 47) a serial sounding was taken, which entirely confirmed the results of tbe first (No. 40) :— Surface. s 2 ee es ya ew w 20 9C 10 fathoms . . . . . . 1. 15 20 ~=C«« Ss da th pi el ge gel aa B30. 8 g,. -44 ody rfin ee yesh. Be eS LOS 40, ; OUR 2 Bo wor 28 50, 4 hag oe gy LB, 100, Ssh a . 12°6 6 8 5; eS ene Gos 12° 192 THE DEPTHS OF THE SEA. [cnap. Iv. —again a mass of water lying at the bottom, 745 fathoms—not far from a mile—in depth, at the uniform temperature of 12°6C. (54°:7 F.) The dredge was sent down at each successive station, but with very poor result; and Dr. Car- penter was driven to the conclusion that the bottom of the Mediterranean at depths beyond a few hundred fathoms is nearly azoic. The conditions are not actually inconsistent with the existence of animal life, for at most of the stations some few living forms were met with, but they are certainly singularly un- favourable. Thus at Station 49, at a depth of 1412 fathoms, and a temperature of 12°:7 C., the following species of mollusca were obtained : NMucula quadrata, n.sp.; NV. pumila, ABSJORNSEN ; Leda, n. sp.; Verti- cordia granulata, Srec.; Hela tenella, JEFFREYS; Trochus gemmulatus, Pu.; Rissoa subsoluta, ARADAS ; Natica affinis, Gmetin; TLrophon multilamellosus, Pu.; Nassa prismatica, Br.; Columbella haliati, JEFF.; Buccinium acuticostatum, Pu.; Pleurotoma carinatum, CRISTOFORI and Jan; P. torquatum, Pu.; P. decussatum, Pu. Near the African coast the fauna was more abun- dant, but the bottom was so rough that it was unsafe to use the dredge, and the tangles were usually sent down alone. Many polyzoa, echinoderms, corals, and sponges were taken in this way, but they were mostly well-known Mediterranean species. After remaining for a few days at Tunis and visiting the ruins of Carthage, dredging was resumed on the 6th of September on the ‘ Adventure’ Bank, so called from its having been discovered by Admiral Smyth when surveying in H.M.S. ‘Adventure.’ Here, at depths cHar.iv.] ‘T/7E CRUISES OF THE ‘ PORCUPINE.’ 193 from 30 to 250 fathoms, animal life was tolerably abundant. With other mollusca the following were found: —Trochus suturalis, Pu. (Sicilian fossil) ; Xenophora crispa, Kénte (Sic. fossil) ; Cylichna striatula, Forpes (Sic. fossil); C. ovulata, BRroccat (Sic. fossil); Gadinia excentrica, TIBERI; Scalaria frondosa, J. SowERByY (Sicilian and Coralline Crag fossil); Pyramidella plicosa, BRoNN (Sic. and Cor. Crag fossil); Acteon pusillus, ForseEs (Sic. fossil). The Echinodermata were abundant so far as indi- viduals went, but the number of species was small, and they were nearly all well-known Mediter- ranean forms. Cidaris papillata, LESKE, showing many varieties, but differing in no specific character from the many forms of the same species which range from North Cape to Cape Spartel in the ocean outside. The Mediterranean yarieties of this species are certainly Cidaris hystrix, of Lamarck. I feel a degree of uncertainty about the pretty little Cidaris, described by Philippi under the name of C. affinis. Characteristic examples of it, which are abundant on the ‘Adventure’ Bank and along the African coast, look very distinct. They are of. a beautiful deep rose red, the spines are banded with red and brownish-yellow, and come to a fine point, while those of C. papillata are usually blunt at the point, and frequently even a little expanded or cupped; and the portion of the interambu- lacral plates covered with miliary granules is wider, and two defined rows of body spines nearly of equal size lie up against the bases of the primary spines, over the alveole. These would appear to be cha- racters of specific value, but then again there are fo) 194 THE DEPTHS OF THE SE. [oHap. rv. a mass of intermediate forms; and although after careful consideration I have described the two species as distinct, I find it a matter of great diffi- culty to draw the line between them. Several specimens of a handsome QO ehinvidea. 4. 4 2 4 4 3 Holothuridea . . . ... 8 — 36 Gephyrea . . eg. $6 Vermes : ie eee es . ol — 57 Polyzoa. . . . pe ARS nd 35 Tunitata e208 a ow tg ee Mollusca . . . Brachiopoda ek ee Cage BE, eo | Conchifera. . . . . . . 87 { Cephalophora. . . ee D8 — 133 Arachnida , ; 1 Sere DO nsw: 3 Vee a . . 105 — 106 Of these 24 protozoa, 38 echinoderms, and 13 mol- lusca are from a depth of 450 fathoms. Professor Sars adds: “We may say, according to our present information, that the true deep-water belt commences at about 100 fathoms. The greater number of deep- sea species begin to appear then, though sparingly, and they increase in number of individuals as we descend to 300 fathoms, or in some cases to 450, when investigations have been carried so far. To what depth this belt extends, or whether there is another below it of a different character, is not yet known.”’? In the year 1864, M. Barboza du Bocage, Director ’ Fortsatte Bemerkninger over det dyrske Livs Udbredning i Havets Dybder, af M. Sars. (Vidensk.-Selsk. Forhandlinger for 1868.) T2 276 THE DEPTHS OF THE SEA. [cHar. VI. of the Natural History Museum of Lisbon, greatly surprised the zoological world by a notice of the occurrence on the coast of Portugal of whisps of silicious spicules resembling those of the Hya- lonema of Japan.’ They were brought up by the Setubal shark-fishers, who, it seemed—an equally sin- gular circumstance—-plied their vocation at a depth of 500 fathoms. Professor Perceval Wright, anxious to ascertain the full history of the case and to get Hyalonema in a fresh state, went to Lisbon in the autumn of 1868, and with the assistance of Professor du Bocage and some of his friends procured at Setubal an open boat and a crew of eight men, with “600 fathoms of rope, the dredge, lots of hooks and bait, and provisions for a couple of days. Leav- ing the port of Setubal a little before five o’clock in the evening, we, after a fair night’s sailing, reached what the fishermen signed to me to be the edge of the deep-sea valley, where they were in the habit of fishing for sharks, and there, while thus engaged, they had found the Hyalonema. It was now about five o’clock in the morning ; and the men, having had their breakfast, put the boat up to the wind, and let down the dredge ; before it reached the bottom, about 480 fathoms of rope were run out, some thirty more were allowed for slack, and then we gently drew it— by hoisting a small foresail—for the distance of about a mile along the bottom. It required the united efforts of six men, hauling the line hand over hand, with the assistance of a double pulley-block, to pull in the dredge: the time thus occupied was just an * Proceedings of the Zoological Society of London for the Year 1864, p. 265, CHAP. VI. ] DEEP-SEA DREDGING. to 77 hour. The dredge was nearly full of a tenacious yellowish mud, through which sparkled innumerable long spicules of the Hyalonema; indeed, if you drew your fingers slowly through the mud, you would thereby gather a handful of these spicules. One specimen of Hyalonema, with the long spicules in- serted into the mud and crowned with its expanded sponge-like portions, rewarded my first attempt at dredging at such a depth.”’ This dredging is of especial interest, for it shows that although difficult and laborious, and attended with a certain amount of risk, it is not impossible in an open boat and with a crew of alien fishermen, to test the nature of the bottom and the character of the fauna, even to the great depth of 500 fathoms. In the year 1868, Count L. F. de Pourtales, one of the officers employed in the United States Coast Survey under Professor Pierce, commenced a series of deep dredgings across the gulf-stream off the coast of Florida; which were continued in the following year, and were productive of most valuable results. Many important memoirs at the hands of Count Pourtales, Mr. Alexander Agassiz, Mr. Theodore Lyman and others, have since enriched the pages of the Bulletin of the Museum of Comparative Zoology, and have greatly extended our knowledge of the deep-sea gulf-stream fauna ; and much information has been gained as to the nature of the bottom in those regions, and the changes which are there taking place. Unfortunately a large part of the collections were in Chicago in the * Notes on Deep-sea Dredging, by Edward Perceval Wright, M.D., F.LS., from the Annals and Magazine of Natural History for December 1868. 278 THE DEPTHS OF THE SEA. (cur. vi. hands of Dr. Stimpson for description at the time of the terrible catastrophe which laid a great part of that city in ashes, and were destroyed; but, by a singularly fortunate accident, our colleague Mr. Gwyn Jeffreys happened to be in Chicago shortly before the fire, and Dr. Stimpson gave him a series of duplicates of the moilusca for comparison with the species dredged in the ‘ Porcupine,’ and a valu- able remnant was thus saved. M. de Pourtales, writing to one of the editors of Silliman’s Journal on the 20th of September, 1868, says: ‘The dredg- ings were made outside the Florida reef, at the same time as the deep-sea soundings, in lines ex- tending from the reef to a depth of about 400 to 500 fathoms, so as to develop the figure of the bottom, its formation and fauna. Six such lines were sounded out and dredged over in the space comprised between Sandy Bay and Coffin’s Patches. All of them agree nearly in the following particu- lars: from the reef to about the 100-fathom line, four or five miles off, the bottom consists chiefly of broken shells and very few corals, and is rather barren of life. A second region extends from the neighbourhood of the 100-fathom line to about 300 fathoms; the slope is very gradual, particularly between 100 and 200 fathoms; the bottom is rocky, and is inhabited by quite a rich fauna. The breadth of this band varies from ten to twenty miles. The third region begins between 250 and 300 fathoms, and is the great bed of foraminifera so widely ex- tended over the bottom of the ocean. “From the third region the dredges cue up fewer though not less interesting specimens, the cuap. v1] DEEP-SEA DREDGING. 279 chief of which was a new crinoid belonging to the genus Bourguetticrinus of D’Orbigny; it may even be the species named by him JB. holessieri, which occurs fossil in a recent formation in Guadaloupe, but of which only small pieces of the stem are known. I obtained half-a-dozen specimens between 230 and 800 fathoms, unfortunately more or less injured by the dredge. The deepest cast made was in 517 fathoms; it gave a very handsome Mopsea and some annelids.”’ * The results of the ‘ Lightning’ cruise in 1868, in which dredging was successfully carried down to 650 fathoms, have already been recorded. In the summer of 1870, Mr. Marshall Hall, F.G.S., with an interest in science which is unfortunately rare among yachtsmen, devoted his yacht ‘ Norna’ to deep-sea dredging work during a cruise along the coast of Portugal and Spain. If we may judge by several preliminary sketches which have from time to time appeared at the hands of Mr. Saville Kent, the collections made during this expedition must have been extensive and valuable.? The last researches in order of time are those con- ducted on board H.M.S. ‘Porcupine’ in 1869 and 1870. With the use of a Government surveying ship well found in all necessary appliances every- thing was in our favour, and, as has been already told, dredging was carried down to 2,435 fathoms; 1 American Journal of Science, vol. xevi. p. 413. * Zoological Results of the 1870 Dredging Expedition of the Yacht ‘Norna’ off the coast of Spain and Portugal, communicated to the Biological Section of the British Association, Edinburgh, August 8, 1871. ature, vol. iv. p. 456. 280 THE DEPTHS OF THE SEA. [CHAP, VI. and the fact that there is an abundant and charac- teristic invertebrate fauna at all depths was placed beyond further question. As yet, little more can be said. A grand new field of inquiry has been opened up, but its culture is terribly laborious. Every haul of the dredge brings to light new and unfamiliar forms—-forms which link themselves strangely with the inhabitants of past periods in the eartl’s history ; but as yet we have not the data for generalizing the deep-sea fauna, and speculating on its geological and biological relations; for notwithstanding all our strength and will, the area of the bottom of the deep sea which has been fairly dredged may still be reckoned by the square yard. FUGLO ‘FROM THE EASTERN SHORE OF VIDERO.”” CHAP, VI.] DEEP-SEA DREDGING. APPENDIX A. 281 One of the Dredging Papers issued by the British Association Committee, filled wp by Mr. MacAndrew. DREDGING PAPER No. 5. Date—7th of June, 1849. Locality.—_Off Malta. Depth.—40 fathoms. Distance from Shore.—1 to 2 miles. Ground.—Sand and stones. Region.— No. of living No. of dead Species obtained. specimens. specimens. Observations. Dentalium dentalis . z Numerous. $5 rubescens, or fissura, 1 ! Striated with an % tarentinum, var. (7) 1 undulated ap- pearance. Caecum trachea 2 Pa ee aaa or strangu- Several. 2 With a notched ” ” ” ” ” . apex. Corbula nucleus Several. Nezra cuspidata . she 1 and valves. » costulata 1 2 and valves. Pandora obtusa 2 Psammobia ferroensis Valves. Tellina distorta, a 1 and valves. » balaustina. 3 » Serrata. l and valves. » depressa | 1 valve. Syndosmya tenuis! (prismatiea! i ae Valves. Venus ovata ‘ 2p oe 1 Valves. 282, THE DEPTHS OF THE SEA. [cHar. v1, Species obtaine. No,oftiving | No, ofdeat | buervations, Suleated to the Astarte incrassata? 8 margin, some of them radiated. Cardium papillosum . 1 J minimum 1 levigatum . Ba Valve. Cardita squamosa . 5 Lucina spinifera : 5 Diplodonta rotundata ae 1 valve. Modiola barbata . 1 Nucula nucleus Several. Leda emarginata . : » striata 4 Arca tetragona. 8 » antiquata : 1 valve, Pectunculus glycimeris . land valves. Lima subauriculata . Valves. Pecten jacobzeus Valves. » gibbus Valves. » polymorphus . 2 Valves. «testa. ro 1 » similis Valves. » sulcatus se land ? valves. Anomia patelliformis uf Pileopsis hungaricus . 1 Bulla lignaria . . 1 » eranchii . 2 » hydatis 4 » Striatula . 1 Rissoa bruguieri : 3 » carinata (costata), 2 Longer, destitute » acuta, var. . 5 of ribs, one very large. », desmarestii 3 { Like cimex, but ” ” ae . minute. Natica macilenta . . 2 Eulima polita . 1 » distorta 1 Cheminitzia varicosa . 4 Tnperfect. 5 elegantissima 4 5 indistincta (2) . 2 » ” 3 Eulimella acicula . i 1 Trochus tenuis, or dubius . ais 1 » Magus. . .. Several. » montagui 1 CHAP. VI.] DEEP-SEA DREDGING. 283 Species obtained. ae py Ee Observations. Trochus montagui sine Several. 43 * 2x Several. Turritella terebra. . Few. Small. 3 tricostalis . 1 Cerithum vulgatum, var. 1 7 retrenlatum Several. ; “ %) ee 2 White. Fusus muricatus . 1 . rs 1 ae ‘ apeties at ibraltar. Pleurotoma nanum 1 5 secalinum 1 Murex tetrapterus ‘ ua 2 Chenopus pes-pelecani . . 1 Buccinum ?, i 3 : 1 Mitra ebenea, ; si 1 Bright orange » 1 colour, banded, small, striated Ringicula auriculata . set 2 ‘ Marginella secalina . 3 4 5 clandestina . Several. Several. Cyprea pulex . ss 2 Cidaris histrix . 3 Zoophytes Alge . . CHAPTER VII. DEEP-SEA TEMPERATURES. Ocean Currents and their general Effects on Climate.—Determination of Surface Temperatures. ---Deep-sea Thermometers.—The ordinary Self-registering Thermometer on Six’s principle-—The Miller- Casella modification —The Temperature Observations taken during the Three Cruises of H.M.S. ‘ Porcupine’ in the year 1869, ete. Appendix A.—Surface Temperatures observed on board H.M.S. ‘Porcupine’ during the Summers of 1869 and 1870. Appenpix B.—Temperature of the Sea at different Depths near the Eastern Margin of the North Atlantic Basin, as ascertained by Serial and by Bottom Soundings. AppEnDIx C.—Comparative Rates of Reduction of Temperature with Increase of Depth at Three Stations in different Latitudes, all of them on the Eastern Margin of the Atlantic Basin. AppenDIx D.—Temperature of the Sea at different Depths in the Warm and Cold Areas lying between the North of Scotland, the Shetland Islands, and the Féroe Islands; as ascertained by Serial and by Bottom Soundings. Appenpix E.—Intermediate Bottom Temperatures showing the Inter- mixture of Warm and Cold Currents on the Borders of the Warm and Cold Areas. Ir the surface of this world of ours were one uniform shell of dry land, other circumstances of its central heat, its relation in position to the sun, and to its investing atmospheric envelope, remaining the same, some zones would present certain pecu- cHAP. Vil.] DEEP-SEA TEMPERATURES. 285 liarities in temperature, owing to the mixture of hot and cold currents of air; but in the main, iso- thermal lines, that is to say, lines drawn through places having the same mean temperature, would coincide with parallels of latitude. A glance at any isothermal chart, whether for the whole year, for summer, for winter, or for a single month, will show that this is far from being the case. The lines of equal temperature deviate everywhere, and often most widely, from their normal parallelism with the parallels of latitude and with each other. A glance at the same chart will also show, that while there is an attempt, as it were, on the part of the iso- thermal lines to maintain their normal direction through the centre of great continents, the most. marked curves, indicating the widest extensions of uniform conditions of temperature, are where there is a wide stretch of open sea extending through many degrees of latitude, and consequently includ- ing very different climatal conditions. The lands bordering upon the ocean partake in this general diffusion of heat and amelioration of climate, and hence we have the difference between continental and insular climates—the former giving extremes of summer heat and winter cold, and the latter a much more uniform temperature, somewhat below the normal temperature within the tropics, and usually greatly above it beyond their limits. The islands of Ireland and Great Britain and the west coast of the Scandinavian peninsula are in- volved in the most extreme system of abnormal curves which we have in any of the ocean basins: and to this peculiarity in the distribution of tem- 286 THE DEPTHS OF THE SEA. [cmap. vit. perature in the North Atlantic we are indebted for the singular mildness of our winter climate. The chart Pl. VII., the general result reduced from many hundreds of thousands of individual observations, gives the distribution of the lines of equal mean temperature for the surface of the North Atlantic for the month of July; and it will be seen that the isotherms, instead of passing directly across the ocean, form a series of loops widening and flatten- ing northwards, ali participating in certain secondary deflections which give them a scalloped appearance, but all of them primarily referred to some common cause of the distribution of heat, having its origin somewhere in the region of the Straits of Florida. These peculiarities in the distribution of tempera- ture on the surface of the sea may usually be very immediately traced to the movement of bodies of water to and from regions where the water is exposed to different climatal conditions;—to warm or cold ocean currents, which make themselves manifest like- wise by their transporting power, their effect in speeding or retarding vessels, or diverting them from their courses. Frequently, however, the current, although possibly involving the movement of a vast mass of water, and exerting a powerful influence upon climate, is so slow as to be imperceptible; its steady onward progress being continually masked by local or variable currents, or by the drift of the prevailing winds. The Gulf-stream, the vast ‘warm river’ of the North Atlantic, which produces the most remark- able and valuable deviations of the isothermal lines which we meet with in any part of the world, is in CHAP. VIL. ] DEEP-SEA TEMPERATURES. 287 this way imperceptible by any direct effect upon navigation beyond the 45th parallel of north latitude, a peculiarity which has produced and still produces great misconceptions as to its real character. The mode of determining the surface temperature of the ocean is sufficiently simple. A bucket is let down from the deck of the vessel, dashed about for a little in the water to equalize the temperature, and filled from a depth of a foot or so below the sur- face. The temperature of the water in the bucket is then taken by an ordinary thermometer, whose error is known. A common thermometer of the Kew Observatory pattern graduated to Fahrenheit degrees can be read with a little practice to a quarter of a degree, and a good-sized centigrade thermometer to a tenth. Observations of surface-temperature are usually made every two hours, the temperature of the air being taken with each observation, and the latitude and longitude noted at noon, or more fre- quently by dead reckoning if required. Every observation of the surface-temperature of the sea taken accurately and accompanied by an equally exact note of the date, the geographical position, and the temperature of the air, is of value. The surface observations taken from H.MLS. ‘ Por- cupine’ during her dredging cruise, in the summer of 1869, are given in Appendix A. The surface-temperature of the North Atlantic has been the subject of almost an infinite number of such observations, more or less accurate. Dr. Petermann, in a valuable paper on the northern extension of the Gulf-stream, reduces the means of more than a hundred thousand of these, and deduces the scheme 288 THE DEPTHS OF THE SEA. (CHAP, VII. of curves which has been used with some slight modification in the construction of this chart. Until very recently little or nothing has been known with any certainty about the temperature of the sea at depths below the surface. This is, however, a field of inquiry of very great importance in Physical Geography, as an accurate determination of the tem- perature at different depths is certainly the best, frequently the only available means of determining the depth, width, direction, and generally the path of the warm ocean currents, which are the chief agents in the diffusion of equatorial heat; and more espe- cially of those deeper indraughts of frigid water which return to supply their place and to com- plete the general cycle of oceanic circulation. The main cause of this want of accurate knowledge of deep-sea temperatures is undoubtedly the defective- ness of the instruments which have been hitherto employed. The thermometer which has been almost universally used for this purpose is the ordinary self-registering thermometer on Six’s construction, enclosed in a strong copper case, with valves or apertures below and above to allow a free current of water to pass through the case and over the surface of the instrument. Six’s registering thermometer (Fig. 53) consists of a glass tube bent in the form of a V, one limb terminating in a large cylindrical bulb, entirely filled with a mixture of creosote and water. The bend of the tube contains a column of mercury, and the other limb ends in a small bulb partially filled with creosote and water, but with a large space empty, or rather containing the vapour of the cuap. VIL] DEEP-SEA TEMPERATURES. 289 liquid and slightly compressed air. A small steel index, with a hair tied round it to act as a spring and maintain the index in any position which it may assume, lies free in the tube among the creo- sote at either end of the column of mercury. This thermometer gives its indications solely by the con- traction and expansion of the liquid in the large full bulb, and is consequently liable to some slight error from the effect of variations of temperature upon the liquids in other parts of the tube. When the liquid in the large bulb expands, the column of mer- cury is driven upwards towards the half-empty bulb, and the limb of the tube in which it rises is graduated from below upwards for increasing heat. When the liquid contracts in the bulb, the column of mercury falls in this limb, but rises in the limb terminating in the full bulb, which is graduated from above down- wards. When the thermometer is going to be used the steel indices are drawn down in each limb of the tube by a strong magnet, till they rest on each side on the surface of the mercury. When the thermometer is brought up, the height at which the lower end of the index stands in each tube indicates the limit to which the index has been driven by the mercury, the extreme of heat or cold'to which the instrument has been exposed. Unfortunately, the accuracy of the ordinary Six’s thermometer cannot be depended upon beyond a very limited depth, for the glass of the bulb which contains the expanding fluid yields to the pressure of the water, and, compressing the contained fluid, gives an indication higher than is due to tem- perature alone. This cause of error is not con- U 290 THE DEPTHS OF THE SEA. [emap. vil, stant in its action, as the amount to which the bulb is compressed depends upon its form and upon the thickness and quality of the glass; thus the error of good thermometers of the Hydrographic Office pattern varies from 7°C. to 10°5C. at a pres- sure of 6817 lbs. on the square inch, representing a depth of 2,500 fathoms. In thoroughly well- constructed thermometers, however, such as those made by Casella and Pastorelli for the English Admiralty, the pressure error is tolerably constant ; and Captain Davis, R.N., who has lately conducted important experiments on this point, expresses his opinion that by an extended series of observations a scale might be obtained to correct the ther- mometers hitherto in use to a close approximation to the truth, and thus utilize to some extent obser- vations which have been already made with our ordinary instruments. In the ‘Lightning’ expedition in 1868 we used the ordinary Hydrographic Office pattern, and a large number by different makers were sent with us for testing and comparison. The depths not being very great, the general temperature results came out well, and were among the most singular phenomena which we had to record. Many of the in- struments were very wild at a few hundred fathoms, and several gave way under the pressure. On our return in April 1869, Dr. W. A. Miller, V.P.B.S., attended a meeting of the Deep-Sea Committee of the Royal Society at the Hydrographic Office, and proposed encasing the full bulb in an outer covering of glass containing air, in order to permit the air to be compressed by the pressure of the CHAP, VII.J DEEP-SEA TEMPERATURES. 291 water on the outer shell, and thus protecting the bulb within. Mr. Casella was directed to construct some ther- mometers on this plan, only instead of being filled with air, the outer shell was nearly filled with alcohol warmed to expel a portion of the remaining air, and the chamber was then her- metically sealed, leaving a bell of air and vapour of alcohol to yield to the pressure and relieve the bulb within. The ‘Miller-Casella’ thermometer proved so nearly perfection that it was decided to adopt it in future, and to use it as a standard in a series of experiments which were undertaken to test the ordinary Six’s ‘thermo- meters of the Hydrographic Office pattern. We depended upon _ this thermometer alone in our subsequert cruises in the ‘Porcupine,’ and we found it most satisfactory. During the summer of 1869 temperature observa- tions were taken at upwards of ninety stations, at depths varying from 10 to 2,435 fathoms. Two thermometers, numbered 100 and 103 ~respectively were sent down at every station, and in no instance did they give the least reason to doubt their accuracy. Every D TIEASELUA LONDON Casella modification of Six’s self-regis- tering thermometer. * The large bulb is double, with a layer of liquid and a bell of vapour between the shells, to relieve pressure, observation was taken by Captain Calver himself, the lead with the thermometers attached being in every single instance let down by his own hand, v2 292 THE DEPTHS OF THE SEA. (cHar. vir. and I have always regarded it as a remarkable evidence of my friend’s care and skill that he landed those two precious instruments at the end of the year safe back. at Woolwich. Fig. 58 represents the latest im- provements on the Miller-Casella modification of Six’s self-registering thermometer. The instrument is of small size, to reduce as far as pos- sible the friction in passing through the water. The tube is mounted in ebonite, to avoid the expansion of a wooden mounting in the water, by which the instrument is liable to | ry get jammed in the case. The scale | is of white porcelain, graduated to 1 Fahrenheit degrees; the large bulb 4 is enclosed in an outer shell three- { ! fourths filled with alcohol and her- i( metically sealed. It is right to mention that I am informed by Sir Edward Sabine that the ther- Mwrotecting the “Miler. MOmeters used by Sir John Ross Casellathermometer. The , ends of theeaseaboveand in his Arctic voyage in 1818 were fm tele tao protected somewhat on the same principle, and that a thermometer for resisting pressure was constructed under the directions of the late Admiral Fitzroy, at the suggestion of Mr. Glaisher, which differed from the Miller-Casella pattern in little else than the outer shell being partially filled with mercury instead of alcohol, and in being somewhat less compact and more fragile than the latter instru- 7 Peo 10 147 | 155 Nepean 10 139 | 12°2 ; Midn.| 150 | 14°7 t Copeland Is- * ' August 8th . 2 13:9 | 15°0 ele j) Noon} 14-4 125 gu a | 4a | ae 2 150 | 13°9 6 4 lel |} 16) 8 15:0 | 15-0 6 16°6 | 15°8 10 155 | 153 8 | 133 At Belfast Noon.! 17:2 | 15°8 10 13°3 | 15:0 2 208 | 1671 Midn.| 11:1 | 13°9 4 166 | 15°8 August 5th . 2 irl | 14] 6 139 | 165 4 10°5 | 14°4 8 144 | 15°8 6 12°7 | 146 10 13°6 | 15°8 8 153 | 147 Midn.| 13°9 | 15°5 10 18°3 | 150 August 9th . 2 175 5 15S At Belfast Noon.| 16°9 | 15°5 4 is | Io 2 17°4 6 13°3 | 15°3 4 17-7 | 16°4 8 133 6 12°8 | 155 10 144 | 155 8 At Belfast Noon.| 15°0 | 15°5 10 111 | 15°0 2 161 | 155 Midn.| 10°0 | 15:0 ' 4 16°6 | 15°5 August 6th . 2 | 105 | 14-7 | 6 | 144 | 158 4 10°0 | 144 8 114 | 155 6 125 | 141 10 10°5 | 15°0 8 166 | 144 { Midn.} 10°0 | 14°4 (citar, vir. 340 THE DEPTHS OF THE SEA. 2 28 2 os Be | Be é. | 28 oo S.A s EI ey a5 28 Date and Position. 8 3s ae Date and Position. 5 as BH a ao | #3 m | gs | Es & Be a a2 2 ° Deg. one Cent, ook, Ga. August 10th. 2 111 | 139 |, August 13th. 2 | 195 | 116 4 105 | 14:7 4 | 12-7 | 199 6 105 | 144 6 13°3 | 116 8 ll4 | 144 8 12:0 | 127 10 13°9 10 1l4 | 116 At Belfast Noon.} 15°5 | 150 Midn.} 111 | 122 2 | 150 August 14th. 2 ; 116 | 12:0 4 147 4 114 | 11-4 6 12°7 6 114 | 129 8 119 | 150 8 13°3 | 12°0 10 116 | 144 10 12°7 Midn.| 11°6 | 13:9 || At Stornoway . | Noon.| 155 | 19°2 August 11th. 2 | 105 | 13:9 2 | 161 | 125 4 117 | 13:3 4 15°0 | 12°7 6 122 | 136 6 14:7 8 13°3 | 13°9 8 | 13:3 | 12°29 10 14:4 10 13°3 | 12°5 In Belfast Lough | Noon.| 144 | 14°4 Midn.| 12°7 | 12°2 2 153 j 122 || August 15th. 2 13°3 | 122 4 150 | 13°0 4 | 133 | 122 6 13°9 | 12°2 6 13°3 | 12:2 8 12:°2 | 12°2 8 139 | 122 10 I? | VaF7 10 13'9 | 12:2 Midn.| 12°0 | 11:7 || At Stornoway Noon.| 14°4 | 122 August 12th. 2 |} 122° | 129 2 | 158 | 125 4 UL | 11s 4 | 161 | 125 6 114 | 12°0 6 155 | 125 8 13°3 | 12°5 8 13°3 | 12°5 10 | 17:2 | 12°7 10 | 12-7 | 127 Coll Island, x . Midn.} 13:0 | 12:2 North, 3 miles t Hoos.) es | We August 16th. 2 | 127 | 122 | 2 153 | 13°3 4 127 | 122 4 144 | 122 6 | 133 | 122 6 12°7 | 12:2 8 | 133 | 12°2 8 12:2 | 12°0 2 < 10 | 136 | 122 10 LiF |) 12:2 at. 59°21’ N. ‘ . Midn,| 12:0 | 12:2 | Long. 6° 58" W. Noon.) 183 / 120 | August 13th. 2 | 127 | 116 2 | 13-0 | 122 4 125 | 116 4 | 183 | 122 6 12°7 | 12-0 6 13°3 | 12°2 | 8 12°5 | 12°0 8 127 | 122 10 | 14-7 | 116 10 | 5 | ie Shiant Islands, ) . Midn.| 12°2 : N.N. W. 6 miles if Ba en August 17th. 2 ‘ill | 116 CHAP. VII] DEEP-SEA TEMPERATURES. 841 —— 2 2 o oe f | £2 2. | Be ig Se | 88 ae 4 ge | 838 j Date and Position. 8 aa 3a Date and Position. 2 ga eh a | Be | ge | gs | 53 i abel a ae Deg. : tae ook, icaawe ze Genk | eee August 17th. 4 | 122 | 11-9 at. 60° 35° N. Pe ; gu 6 | 12:2 | 11-9 || Long. 6° 41’ W. ! Noon.| 13°3 | 11°4 8 1293 2 127 | 114 10 139 | 122 ei i Lat. 59° 36’ N. : a ‘4 | 11 Long. 7° 12 W. ! Noon.| 13:9 | 12°2 8 | 94 | 105 | 2 | 136 | 11-9 10 | 97 | 10°0 4 141. | ire Midn.| 100 9-4 6 | 13-0 | 11:9 || August 21st. 2 | 100 9-4 8 123. | 114 4 9°4 974 10 12°7 | 111 6 10°0 9°4 Midn.| 12°2 | 111 8 10°0 | 10°0 -Augnst 18th. 2 129.1 106 ar ee : 10 13°6 97 4 jee 7 2th and& in { . ‘ 6 | 127 | 111 Féroe Islands § Pega.) lee a ; 8 139 | 114 2 114 88 " No) 10 13°6 | 10°8 4 17 91 at. 60° 25’ N. Be ' 6 11°4 91 Long. gs OW. 5 Noon. 13°6 114 8 10°5 91 : 2 12°77 | 111 10 10°8 94 | 4 12°5 | 108 Midn, | 10°5 974 6 io | ti August 22nd 9 10°5 91 8 22 | Atl 4 10°8 94 10 12°2 | 111 6 Led 91 Midn.| 12°2 | 11°1 8 116 9-4 August 19th. 2 TOO | VAL 10 12°7 9-4 4 | 122 | 11:1 || At Thorshavn Noon, | 14°4 94 6 12°7 | 114 2 13°3 97 8 12°7 | 114 4 12°2 | 10:0 inne 10 13°3 | 114 6 13°3 97 at, 60°13 N. ; ; 8 | 105 | 94 Long. 6° Ay WwW. Noon. 12 7 Ill 10 10-0 9°4 2 13°3 | 111 Midn, | 10:0 9°4 4 139 August 28rd 2 94 9°4 : 6 12°7 | 111 4 | 8 | 127 | 111 6 | 108 | 9-4 10 T2274 IA 8 105 9°4 Midn.| 12°2 | 10°5 10 | 127 | 97 August 20th. 2 | 122 | 10% } At Thorshavn Noon.) 12°7 | 9°7 4 12:0 | 10°0 2 12°7 9°4 6 122 | 10°8 4 19°7 9°4 8 125 | 10°5 6 12°2 9°4 10 12°56 | 103 8 Lic 91 342 THE DEPTHS OF THE SEA. (CHAP. VII Temperature of Air Date and Position, 3 5 Deg. Cent August 23rd 10 | 111 Midn.) 11°1 August 24th. Q | ill 4 lil 6 aT: 8 11-4 About 10 miles | ile ou miles ( Be East of Haalso § Noon. | 15° 2 120 4 13°3 6 Tal 8 111 10 105 Midn.} 11°1 August 25th. 2 | 116 4 1136 6 12°5 8 125 ; a4 10 | 125 at. 61° 36’ N. Long. 3° 45’ W. § Noon. | 12°2 2 12°2 4 11°6 6 11°6 8 11°4 10 114 Midn.| 12°0 August 26th. 2 | 12°0 4 12°0 6 12°0 8 | 12°0 - < 10 12°2 at. 61°14 N. ; Long. 1° 58’ W. ! Noon.) 12°7 2 | 12°7 4 | 116 6 Ill 8 {116 10 11°6 Midn,} 11°4 August 27th, 2 |) 11st 4 ae 6 11, oe: o Oo v Eg Date and Position. 5 a4 Be oa fan Boy os Ea B° | Bi iv AB Ae Deg. Deg. Deg. Cent. Cent, Cent, 9-4 | August 27th. . 8 | 111 | 114 91 Lat, 60° 36'N, } 10 | 116 | 11°6 OT ab. . : F 9°4 Long. 0° 15’ E. ( Sees 125 | 116 94 2 13°3 | 12-2 91 4 | 122 | 119 91 6 lll | 119 91 8 LL | 2¢ 10 L030. |) 262 o7 Midn.; 9°4 | 111 10°0 August 28th. 2 10°5 | 116 94 4 2 | iG 94 6 119 | 119 9°4 8 10°0 | Ill 9°4 10 100 | 111 9-7 || At Lerwick . . !Noon,! 9-4 | 111 97 2 105. | Ill 94 4 mg 97 6 97 | lll 9:4 8 88 | 111 94 10 75. | V1 Midn.| 7:2 | 111 9°7 || August 29th. 2 72 | il 9-4 4 77 | 103 94 6 77} 114 97 8 94 | 111 01. 10 97 | 111 10°5 |; At Lerwick . ‘Noon.| 9°4 | 111 111 2 94 | Ill M1 4 94 |} 111 Lil. 6 91 | Ill 11°4 8 Te |} Ue 116 10 77 | 108 11-4 Midn.| 89 | 10°8 August 30th. 2 83 | 111 114 4 Ta 114 6 83 | 108 114 8 10°3 | 111 114 10 THI | Veh 111 |) At Lerwick . Noon.| 11°6 | 111 alaigi 2 ya7 | 14 It 4 122 | 111 LeL 6 oh Oa [38e | ee ] ae CHAP. VII.] DEEP-SEA TEMPERATURES. 343 Date and Position. 2 Eq ER Date and Position. E Eg oa ral me Bg o Be Es 8 Ba B° | Es aA Ete a Fas Deg. Deg Deg. Deg. Cent. | Cent. Cent. Cent. August 30th. 10 72 | 111 ee oo : 10 13:0 | 11°6 Midn.| 6°6 | 111 at. 60° 3° N, “es August 31st . 2°| 721105 |) Long. 5°10 W. 5 | Noo.) 12°7 | 11°6 4 77 | 10°5 2 T285: |, TG 6 10:0° |) 111 4 tore iG 8 100 | 111 6 122 | ll-4 10 116 | 10°8 8 12°5 | ll-4 At Lerwick . Noon.| 12°2 | 111 O° | E27 4 1G: 2 13°6 | 111 Midn.) 12°7 | 12°2 4 1T1 | il September 4th , 2 12-7 ‘| 12:2 6 10°56 | 111 4 13°3 | 122 8 pe fl 6 TBO. 4 235: 10 10°8 | 10°8 8 13°9 | 12°5 Midn.} 10°5 | ill 3 10 14-4 | 12°2 September Ist . Q | 111 | 11:1 || Lat. 59° 43’ N. ne we 4 | 111 | 116 i Loug, 6° 35° Ww, | Noon.) 18°3 | 122 6 11°6 | 116 2 13°3 | 12:2 8 11°6 | 116 4 13°0 | 12°2 10 lll | 114 6 Ea7 | 129, Lat. 60° 27° N. é : 8 127 | 116 Long. 3° 11’ W. Noo) TET | 116 10 | 122 | 11°6 2 122 | 116 Midn.| 12°5 | 12°0 4 | 133 | 114 |} September 5th . 2 | 122 | 12°0 6 116 | 111 4 12:5) 16 8 114 | 111 6 P27 | eG 10 1l‘1 | 116 8 12°77 | 116 ravers Midn.} 11:1 | 11°6 : 10 13°3 | 12°0 eptember 2nd . 2 | 108 | 108 |) Lat. 59°38 N. ) aoe 4 | 108 | 105 || Long. 8°25 w. | Noon.| 144 | 122 6 111 | 10°3 2 13°6 | 116 8 111 | 103 4 12°0 | 116 ree 10 EPL. 10°83 6 TT |) a6 at. ¢ ‘ F 8 111 | 116 Long, 4° 38° W. Noon.} 11°4 | 10-0 10 | 108 | 114 2 114 | 103 jf. Midn.! 111 | 11-4 4 | 116 | 10 |) September 6th . 2. (AED | ed 6 116 } 111 4 lll | 114 8 AVY 11 6 12'2 | 11°6 10 11°6 | 11°4 8 13°0 | 116 Midn,| 111 | 116 10 12°7 | 12:0 September 3rd . 2 | 116 | 11:1 |) Lat. 59°37’ N, N 127 | 19% 4 | 111 | 111 || Long. 9° 4’ W. won J 6 Ill } 116 2 13°0 8 116 | 116 4 1D | 122 344 THE DEPTHS OF THE SEA. [cuar. vii. | 3) oe 7) oo g Be 2. | #8 es S et ss a a 3.4 ea Date and Position. | S 54 DA Date and Position. 3 Be SD |) H | Bs | #3 mo] as | Bs | a BY a Bs September 6th . 6 | 12:2 | 12:0 || September 10th 6 | 144 | 12-7 8 122 | 122 8 150 | 12°7 10 122 | 12:2 10 139 | 12°7 Midn.| 11°6 | 11:6 || At Stornoway . | Noon.| 16°3 | 13:3 September 7th . 2 | 114 | 116 2 | 163 | 13°9 4 10°5 | 116 4 | 150 | 136 6 105 | 11:9 6 | 139 | 133 8 122 | 116 8 12°7 | 133 i: iP ee 10 147 | 119 re 12°2 | 130 at. 59° 41’ N, . : idn.) 11°6 | 12°7 Long. 7° 32’ W. Noon.) 155 | 122 || gontember 11th 2 | 111 | 197 2 13°9 | 12°2 4 ; 111 | 127 4 13°3 | 12°2 6 111 | 12-7 6 12°7 | 12:2 8 111 | 12°7 8- | 125 | 12°5 10 | 139 | 12°7 10 | 12°7 | 12:2 || At Stornoway Noon.| 15:3 | 12°7 Midn.| 12:2 | 12:2 2 13°3 | 12°2 September 8th . 2 | 122 | 116 4 / 116 | 197 4 12°7 | 11°9 6 114 | 12°7 6 12°7 | 11:9 8 108 | 12°7 8 13°6 | 12°2 10 97 | 129 " ae 10 150 | 12°7 e " Midn.| 9°4 | 12°2 at. 59° 7’ N. : : eptember 12th 2 91 | 12°2 Long. 6° 35° W. Noon.| 144 | 127 || **P 4 | 89 | 122 2 15°3 | 12-7 6 94 | 122 4 155 | 12°7 8 114 | 12:2 6 13°3 | 12°5 10 | 125 | 122 8 | 133 | 12°56 || At Stornoway Noon.} 12°7 | 12°2 10 13°3 | 13°0 2 | 12°7 | 125 Midn.t 12°7 | 13-0 4 | 127 | 125 September 9th . 2 13°3 | 12°7 6 | lll | 122 4 13°3 | 12°7 8 | 105 | 122 6 13°3 | 12°7 10 | 10°0 | 12°2 8 | 13:0 | 12°7 Midn.} 11:1 | 120 10 | 13°3 | 12°7 || September 13th 2 | 100 | 116 At Stornoway Noon.} 13°9 | 12°7 4 91} ILl 2 ' 6 | 111 | 116 4 14-4 | 12°7 8 | 111 | 116 6 15°33 | 12-7 10 | 130 | 122 8 | 155 | 12°7 || In Loch Sheil- : , 10 | 155 |133 |) dag... in| eee Midn.| 15°5 | 12°7 2 } 141 | 122 September 10th 2 | 139 | 12°7 4 | 144 | 122 4 | 144 | 127 6 | 139 | 122 CHAP. VII.] DEEP-SEA TEMPERATURES. 2 | 28 2 | #2 Date and Position. 5 #4 #2 Z : 4 : z # 8 Be 2 5 Date and Position. 8 eS Be a abe a Be i—} o Gent. | Gon Ceut, | Cent September 13th 8 | 13:0 | 122 || Abreast of Mull | Noon.| 12°7 | 13°0 10 | 12°2 | 12-2 2 144 | 13°3 Midn,| 12°2 | 12-2 4 144 | 13°3 September 14th 2 | 116 | 12°5 6 | 136 | 12°7 4 | 122 | 12:2 8 | 13°0 | 13°3 6 | 125 | 12°2 10 125 | 13°0 8 | 122 | 12°7 Midn.} 120 | 13°0 10 | 116 | 12°7 II. Surrack TEMPERATURES OBSERVED DURING THE SUMMER OF 1870. | | B | 82 | 8a 2} ga | 6 Date and Position. 8 Bs = 4 Date and Position. § Bes é o on D on A As i= By Deg. Deg. Deg. Deg Cent. Cent. Cent. Cent July 6th . 2 | 139 | 12:2 || July 7th . 6 | 194 | 164 4 144 | 12°7 8 17-2 | 161 6 139 | 12°5 10 169 | 16°4 8 14°7 | 147 Midn.| 16°6 | 16°4 10 15°3 | 136 || July 8th . 2 166 | 161 Off Scilly Islands | Noon.| 18°6 | 18°3 4 | 161 | 161 2 19°7 | 17-4 6 169 | 1671 4 194 | 183 8 191 | 16°2 6 18°9 co " 10 20°8 | 161 8 174 | 17° at. 48°31' N. ; . 10 | 166 | 17-2 || Long. 10° 6’ W. \ ooh, | Tae || E12 Midn.} 16:1 | 17:2 2 20°0 | 17°5 July 7th . 2 166 | 166 4 18°6 | 175 4 166 | 16°6 6 191 | 175 6 16°6 | 16°6 8 17°77 | 17-2 8 169 | 169 10 169 | 17°2 i ana y \ 10 17-7 | 16°4 Midn.|} 16°6 | 16-9 at, 48° 49’ N. : July 9th . 2 1671 | 16:9 Long. 9° 35" W. f Noon. 183 16°4 y 4 166 16°6 2 194 | 164 6 161 | 16°6 4 189 | 17°2 8 161 | 16°6 346 THE DEPTHS OF THE SEA. [cHap. VII. s eH | #3 5 Date and Position. & zs 5 Date and Position. g a BS Deg. Deg. Cent. Cent July 9th. . 10 | 175 | 166 |) July 12th 6 Lat. 48° 26’ N. ; . 8 Long. 9° 43' Ww. Noon. | 17°5 16°6 10 2 16°4 | 16°6 Midn. 4 172 | 166 | July 13th 2 6 16°4 | 16°6 4 8 16°4 | 1671 6 10 166 | 16°6 8 4 " Midn.| 16:1 | 16°4 " r 10 uly 1Ot 2 1671 | 166 at. 44° 59’ N. r 4 | 16-4 | 164 || Long. 9° 33’ W, {| Noon. 6 166 | 16°4 2 8 164 | 16°4 4 a < 10 173 | 166 6 at. 48° 28’ N. a . a 8 Long. 9° 42° W. Noon.| 16°1 | 16°6 10 2 /17°7 | 169 Midn, 4 194 | 16°9 || July 14th 2 6 19°6 | 16°6 4 8 16°2'| 16°6 6 10 1G1 | 161 8 Midn.| 1671 16'1 10 July 11th 2 | 161 | 166 | Cape Finisterre, 4 | 164 | 164 EL NLN. Noon 6 | 164 | 161 10 miles . 8 18°3 | 1671 2 ‘ Fe 10 18°6 | 16°6 4 at. 48° 8'N, ’ . 6 Long, 9° 18’ W. Noon.| 18°6 | 16°9 8 2 184 | 17:2 10 4 191 | 17:3 |! Midn. 6 | 173 | 174 | July 15th 2 8 166 | 166 4 10 PED: | WED 6 Midn.) 17-2 | 17°7 8 July 12th 2) WE |) WA 10 4 ile ay am Wn 7a 8 Lat. 42° 11’ N. N 6 | 174 | 180 || Long. 9° 13’ W. aaa 8 17-7 | 183 2 10 186 | 18:0 4 Lat. 46° 26’ N. ‘ _ 6 Long. 9° 31’ W. Noon.} 191 | 182 8 2 | 19-4 | 180 | 10 4 117: 18:0 Midn. Temperature of Air Temperature of Sea-Surface, CHAP. VII. ] DEEP-SEA TEMPERATURES. 347 Date and Position. July 16th At Vigo . July 17th July 18th Lat, 41° 55° N. Long. 9° 30’ W. _ July 19th | Lat. 40° 16" N, Long. 9° 33’ W. Hour. SOMOS ALD a Dapros 5 E.. : Sm to By Z or ° B OB NO BS Gow bo ‘bt e o ge | # § ea | @ a a4 Date and Position. 8 ES es a aS al Ay Deg. Deg. Deg. Deg. Cent. Ceut. Cent, Cent. 155 | 19°0 July 19th 2 20°3 | 18°0 17°2 |} 18°9 4 20°3 | 18°0 18°3 | 17°9 6 195 | 179 20°1 | 19°4 8 | 194 | 18°3 932 | 179 10 18°9 | 184 23°6 | 17°8 Midn.| 18°6 | 18°4 23°6 | 17°9 July 20th 2 183 | 18°3 23°4 | 18°0 4 18°3 | 183 216 | 172 6 19'4 | 18°4 184 | 161 8 | 24:4 | 18°9 17°77 | 16°6 , 10 23°3 | 20°5 17'2 | 16°9 at. 40° O' N. . ; : 17°7 | 161 || Long. 9° 49° w. §}Noon.| 244 | 214 17:5 | 16:5 2 25°5 | Qi°1 17°7 | 16°6 4 | 263 | 91°8 19°7 | 16°4 6 | 23:3 | 21°8 222 | 161 8 216 | 19°7 32°2 | 16°4 10 21°3 | 20°8 26°6 | 16°9 Midn,} 21°3 | 20°5 25°38 | 15°8 || July 21st. 2 211 | 205 22°5 | 16°4 4 21:5 | 19°7 20°8 | 16°4 6 23°3 | 18°9 200 | 16°5 8 | 22°7 | 19°4 18°6 | 162 . 7 10 24:5 | 19°4 183 | 16°4 at, 39° 39’ N. . : 17-7 Long. 9° 36" W. Noon.| 25°5 | 19°4 189 | 161 2 25°0 | 194 19°4 | 16°6 4 23°9 | 19°7 18°9 6 21°83 | 19°4 . ¥ 8 20'1 | 19°4 seed | ecctes 10 | 196 | 19-4 186 | 16°3 Midn.} 19°5 | 1971 189 | 16°3 July 22nd 2 194 | 189 189 | 16°4 4 | 189 | 18°9 18°3 | 16°6 6 | 20:0 | 18:2 183 | 16°6 8 | 212 | 18:3 ee 16'4 mE 10 | 25:0 | 19°4 17° 169 e arilhoes. 177 | 169 || SSE. 5 miles Noon.} 250 | 189 194 | 169 2 | 239 | 191 20°38 | 175 4 | 23°3 | 20°5 20°71 | 17°7 6 23°9 | 194 r “ 8 20°0 | 19°4 208. | ee 10 | 189 | 18:3 348 THE DEPTHS OF THE SE4. [cHAP. VIL. 2 2g 2 5 is oI os B4 3 =; u 8.5 Date and Position. & Be Bs Date and Position. g Bs a BS & eg. d Mid cent. | ca Lat. 38°17 N cat July 22n idn.| 19°1 | 18°0 at. 38° 17° N. ; ale 23rd 2 | 189 | 185 || Long, 9°23 w. {| Noon.) 20° 4 | 193 | 19-4 2 | 20°0 6 | 205 | 183 4 | 20°0 8 | 23-3 | 20°5 6 | 200 10 | 24°7 | 22:0 8 | 194 At Lisbon Noon.| 22°5 | 2171 10 | 20:0 2 | 236 | 191 Midn.| 20-0 4 | 21-6 | 200 | July 27th Q | 194 6 | 23-0 | 21°6 4 | 19-4 8 | 205 | 203 6 | 19:4 10 | 195 | 197 8 | 20°0 Midn.! 20°1 | 195 ee lo | 21:3 July 24th 2 | 19:4 | 186 || Lat. 37°18 N, ; e 4 | 19-4 | 205 || Long. 9°12 w. 5 |Noom) 211 6 | 2071 | 21°6 2 | 23:3 8 | 20°83 | 20°8 4 | 211 10 | 21-2 | 2071 6 | 20°0 At Lisbon Noon.| 24:1 | 19°4 8 | 20°0 2 | 23-0 | 20°5 10 | 194 4 | 231 | 201 Midn.| 19°5 6 | 222 | 21-2 | July 28th 2 | 194 8 | 205 | 21-4 4 | 194 10 | 20:0 | 20-0 6 | 1971 Midn.| 19:4 | 19-7 8 | 211 July 25th 2 | 191 | 20-0 10 | 211 4 | 19-0 | 20:0 || Lat. 36° 55° N. ; 6 | 20:3 | 191 || Long 8° 44 w. 5 |Noom.| 21°8 8 | 204 | 19-4 2 | 21°6 10 | 20°8 | 191 4 | 216 Lat. 38° 10’ N. y . 6 | 205 Long. 9° 29’ W. Noon.) 21°8 | 19°4 8 | is-9 Q | Qrd1 | 19-4 10 | 189 4 | 208 | 19-4 Midn.| 18°6 6 | 216 | 19°4 || July 29th 2 | 183 8 | 20:0 | 18-0 4 | 183 10 | 186 | 17°7 6 | a1 Midn.| 18-0 | 17-7 8 | 22-1 July 26th 2 1183 | 17-4 10 | 23°0 4 | 183 | 17-7 | Lat, 36° 45° N, : 6 | 19:1 | 191 | Long 8° 8 w. 5 | Noon. 233 8 | 194 | 191 2 | 233 10 | 20°3 | 19°3 4 | 24° Temperature of Sea-Surface. CHAP. vit.] DEEP-SEA TEMPERATURES. 349 ro oo ro) og 5 Ze ae ee BE E Ba & 4 @ @ iti & Sq Sw Date and Position. 5 34 Sa Date and Position. rc eS 2 Fi | BS z 3 a By Se By Deg. Gant: | cat Gent | Gene July 29th 6 | 222 | 225 | August 2nd . 8 | 217 | 23-9 8 Ql | 22°3 10 22°38 | 24-4 10 21) |) 216 Lat. 36°18’ N. ) , ‘ Midn.| 20°5 | 21-6 || Long. 6° 45’ W. § Se ae ea July 30th 2 20'°3 | 21°9 2 22°5 | 23:0 4 205 | 22-2 4 22°7 | 23-0 6 20°5 | 22°38 6 21°8 | 22°8 8 22°4 | 22°5 8 212 | 92-2 10 O33 | 22:9 10 21°3 | 29'5 Lat. 36° 27’ N. if ae Midn.} 211 | 29:2 Long 6° 39 W. Noon.} 23°9 | 23°1 1 anoust ard . 2 | 205 | 22-0 2 25°3 | 24-1 4 20°5 | 22:0 4 Ooo | 2 6 21°8 | 99°8 6 o28 | 249 8 23°7 | 22-2 8 216 | 241 . 10 23°3 | 21°8 10 216 | 24:3 at. 35° 39° N. , ' Midn.| 21°5 | 24:3 || Long. 7° 4’ W. {| Noon.| 21°6 | 22-0 July 31st. 2 Qi1 | 22°8 2 22°6 | 999 4 219 | 23°3 4 241. | 222 6 219 | 23°6 6 23°2 | 29'°9 8 O25 | 24°) 8 21°8 | 29°29 10 245 | 239 10 21°8 | 22:0 At Cadiz . Noon. | 25°2 | 24:0 Midn. | 22°5 | 23-0 | 2 Q5'1 | 24-1 August 4th . 2 22°2 | 999 4 | 24:0 | 243 4 | 299 | 99-9 6 Q4'0 | 24°4 6 23°2 | 99°9 8 93'4 | 244 8 23°9 | 22°9 en Q2°7 | 24-1 7 10 24°4 | 93°3 idn.| 22°5 | 24°] at. 35° 35’ N. ‘ 3 Angust Ist 2 | 223 | 23-9 || Long. 6° 24 w. {| Noon-| 25°0 | 23:3 4 216 | 22°8 2 27°2 | 23-4 6 225 | 23°9 4 25°6 | 23°3 8 944 | 947 6 244 | 93°3 10 241 | 24:4 8 22°2 | 21°8 At Cadiz . Noon.| 23°9 | 24°7 10 | 22:2 | 92:0 2 23°6 | 24-4 Midn.} 22°2 | 22°92 4 | 23°6 | 24:4 || October Ist . 2 | 17-4 | 18°9 6 216 | 23°3 4 17°8 | 18°9 8 216 | 23°6 6 18°0 | 18°0 10 216 | 239 8 194 | 17°9 iheg cae Midn.} 21°8 | 23°9 10 22°1 | 21°5 ust 2nd , 2 | 21'9 | 23°3 || In Strait — of : : 4 | 213 | 23:0 || Gibraltar . Moon, | 28e: | 22 6 21°6 | 23°3 2 241 | 23°4 (CHAP. VII, 350 THE DEPTHS OF THE SEA. Date and Position. 3 Es e 3 Date and Position on a Ay Deg. Deg Cent. Cent, October Ist . 4 | 225 | 22:8 |) October 5th . 6 22°0 | 22°6 8 2V1 | 29°5 10 215 | 222 Midn.| 20°8 | 22°6 October 2nd . 2 | QU1 | 23°8 }; Lat, 43° 33’ N, 4 | 22°3 | 23:3 || Long. 9° 3’ W. 6 22°6 | 22°9 8 24°7 | 23-2 10 247 | 23°3 Lat. 36° 27' N. Long. 8° 31’ W. § October 3rd . Lat. 38° 39’ N. Long. 9° 30° W. October 4th . Lat. 40°57 N, Long. 9° 29’ W. 4 | 23°7 | 23:0 |} October 6th . 2 | 20°0 | 2171 | Lat. 46° 12” N. 4 | 194 | 183 || Long. 8° 8 W. 4 | 21:1 } 2171 | October 7th . 2 | 20°38 | 21:1 | Lat. 48° 51’ N, 4 | 20° | 21:1 | Long. 5° 54’ W. 4 | 22°2 | 21:0 || October 8th . Hour. Temperature of Air. CHAP, VII.] DEEP-SEA TEMPERATURES. 301 53 | BB |] £2 # | 4 | BB Date aud Position. S aA aR Date and Position. S Es 22 y eS eS a =r) aS oO DR D DQ ima) Ay RB ete Deg. Deg. Deg. Deg. Cent Cent Cent. Cent. St. Alban’s Hd., October 8th . 6 | 15:0 | 15°8 English Chan- >| Noon.| 18°6 | 16°2 8 | 147 | 15°7 c1\.) ny eae 10 155 | 15°6 2 | 195 | 16:0 || At Cowes Midn.| 15°3 | 15°5 4 | 166 | 158 352 THE DEPTHS OF THE SEA. APPENDIX B. [CHAP. \11, Temperature of the Sea at different Depths near the Eastern Margin of the North Atlantic Basin, as ascertained by Serial and by Bottom Soundings. SeR1aL SOUNDINGS. | Botrom SounpIncs. Tempe-|Tempe-)Tempe-|Tempe-|Tempe-|Tempe-/Tempe-| Sta- Surface | Bottom Depth.| rature.| rature.| rature | rature.|rature.| rature.| rature.| tion. |Depth.| Tempe- | Tempe- Ser. 23.|Ser. 42./Ser. 22.\Ser. 19./Ser. 20 |Ser. 21./Ser. 38. | No. rature. | rature, Deg. | Deg. | Deg. | Deg. | Deg. x, | Deg. Deg. Deg. Fms. | Cent. cane Gent. Cent. Gai, ene Cent. Fms. Cent. Cent 0 | 14:0 | 17:0 | 13°8 | 12°6 | 18-0 | 13-4 | 17-7 50 ol 18 27 54 13+1 0 84 76 18°9 9°8 6 90) 12:2 10-0 35 96 17-4 Nita 100 9-1 | 10°6 8 106 12:3 10°6 24 109 14:3 8-0 150 10°5 7 159 118 10-2 14 173 118 9-7 18 188 | 11:8 9°6 200 8-9 | 10:2 13 208 120 9-7 250 10'1 91 8-9 91.) 9-0 | 10:2 4 251 12-0 97 300 87 9-7 26 345 14:1 8-1 350 95° 1 370 12-2 9-4 400 86 91 ao 422, 2 8:3 450 86 45 458 15°9 8:9 500 ae 8:5 81 81 83 86 8°8 40 517 | 17-4 87 550 aes 8-0 39 gor | 172 8:3 600 eg T5 41 584 | 17:4 8-0 630 63 650 6°8 23b 664 14-1 5:3 700 6-4 12 670 | 11-2 59 3 723 125 61 36 (20 | Itt 66 750 |. 58) 55) 51] 53] 57) 5:2 800 oe 5:5 2 808 | 12:3 5:2 16 816 | 11:6 41 862 |... 43 44 865 | 16:2 41 1000 eo ers 37 3°6 387 36 20 43 1207 | 165 3-1 28 1215 | 14:2 28 17 (| 1230; 11:8 3:2 1250 31) 32] 3-1 29 | 1264 |) 13:8 27 1300 39. | 1320 13:3 30 1360 3°0 30 1880 | 13°3 28 1400 1443 27 1476 see 27 1500 a 2-9 1750 26 2090 2:4 37 | 2485 | 186 25 cHaP. VIL] DEEP-SEA TEMPERATURES. 353 APPENDIX C. Comparative Rates of Reduction of Temperature with Increase of Depth at Three Stations in different Latitudes, all of them on the Eastern Margin of the Atlantic Basin. Sration 42. Station 23. Srarron 87. Lat, 49° 12". Lat. 56° 13’. Lat. 59° 85’. Depth. ae Difference ge ae Difference. cae ae Difference. Fathoms, Surface. 17° 0C. 14°°0C, 11" 4C. 6° 4C 4°90, 2° 90. 100 10°6 9°1 8°5 0°4 0:2 0°3 200 10°2 8°9 8:2 0°5 0°2 O°l 300 9°7 8°7 8-1 0°6 oO°l 0°3 400 9°1 8°6 ies 1°0 1°'0 0°5 500 8:1 7°6 Ws 0°6 0°7 1°2 600 yaa) 6°'9 6°1 1°‘7 750 5:8 0-9 767 5°39 354 THE DEPTHS OF THE SEA. APPENDIX D. [cHAr. VII. Temperature of the Sea at different Depths in the Warm and Cold Areas lying between the North of Scotland, the Shetland Islands, and the Ferve Islands; as ascertained by Serial and by Bottom Soundings. N.B.—The Roman numerals indicate the ‘ Lightning’ Temperature Soundings, corrected for pressure. WarRM AREA, CoLp AREA. Series 87. Sta- peewee nares Series 64. Ser, 52.) gta. leita Bottom - pe Depth. vempe- yeinDes pa Depth. Tempe- Conve empe- oO. rature, | rature. @: = | NOs. oT rature. Depth. | ature Dent) Fee | ee ae Deg. Deg. | Deg. Deg. Deg. | Deg. | Deg. Fis. | Cent. Fins. | Cent. | Cent. || Fms. Cent Cent. Fms. Cent. | Cent. O | Il 0 9°8 1 59 8-9 | 73 84 | 15 | 9:3 50 75 9-1 70 | 66 (119) 7:3 80 92 | 11:8] 96 69 | 67 | 119] 65 109 85 100 72 85 68 | 75 | 14] 66 71 | 103 | 11:6 | 9:2 6L | 114 | 102] 72 81 (142 | 11°83] 9-5 62 | 125 | 97) 7:0 150 83) 84 | 155 | 123] 9-5 || 150 6-2 8-0 60 | 167 | 97) 68 85 | 190 | 121] 92 IX. | 170 | 111) 50 200 8-2 200 4-2 75 74 | 203 | 11-4) 8-7 250 12 3-5 300 81 300 0-2 | --0-7 63 | 317 | 94|—-10 65 | 345 | 111} —-12 76 | 344 | 10-2 | -13 50 | 355 | 11:4] 7-9 || 350 | —0-3 54 | 363 | 11-4 | —03 46 | 3874 | 121] 7-7 || 384 —0°8 400 78 400 | —0-6 86 | 445 | 120 | —11 89 | 445 | 11°7| 7:5 | 459 | —0°8 90 | 458 | 11-7 | 7:3 53 | 480 | 11-4 | -07 49 | 475 | 12:0 | 74 53 | 499 | 112} -11 500 | 72 500 | —1-1 X. | 500 | 105 | -07 XIE | 530 | 11-4) 71 58 | 540 | 10-8 | —07 47 | 542 | 122) 65 VIII. | 550 | 11:6 | -13 XV. | 570 | 11-1] 63 || 550 | —11 77 | 560 | 105|—-18 59 | 580 | 11-5} —1°3 600 | 6-1 600 | —1:2 XVIT.| 620 | 11-1] 63 55 | 605 | 11-4] —-138 XIV. | 650. | 11-6 | 5:8 57 | 632 | 111 |-08 640 | —1-4 700 88 | 705 | 11:9] 5-9 767 52 CHAP. VU. ] DEEP-SEA TEMPERATURES. 395 APPENDIX E. Intermediate Bottom Temperatures, showing the Intermiature of Warm and Cold Currents on the Borders of the Warm and Cold Areas. ‘ Surf Bott Stott Surfe Bott Ste | Depth Re peas | Tempers: Beet | Hepth; Motparas | Uemperde Fai ture. ture. ture. ture. Deg. Deg. Deg. Deg. Fathoms. Cent. Cent. Fathoms. Cent. Cent. 72 76 11°3 9°3 75 250 10°8 55 79 76 11°2 93 78 290 112 53 73 84 115 9°3 82 312 113 51 71 103 11°6 92 83 362 11°8 30 74 203 14 87 66 267 lit 76 15 440 10°9 56 AAQ CHAPTER VIII. THE GULF-STREAM. The Range of the ‘Porcupine’ Temperature Observations.—Low Temperatures universal at great Depths.—The Difficulty of in- vestigating Ocean Currents.-—The Doctrine of a general Oceanic Circulation advocated by Captain Maury and by Dr. Carpenter.— Opinion expressed by Sir John Herschel.—The Origin and Exten- sion of the Gulf-stream.—The Views of Captain Maury; of Pro- fessor Buff; of Dr. Carpenter.—The Gulf-stream off the Coast of North America.—Professor Bache’s ‘Sections.’-—The Gulfstream traced by the Surface Temperatures of the North Atlantic.—Mr. Findlay’s Views.—Dr. Petermann’s Temperature Charts.—Sources of the underlying Cold Water.—The Arctic Return Currents.— Antarctic Indraught.—Vertical Distribution of Temperature in the North Atlantic Basin. Aut the temperature investigations carried on in H.M.S.S. ‘Lightning’ and ‘Porcupine’ during the years 1868-69 and 1870, with the exception of a series of observations already referred to taken in the Mediterranean under Dr. Carpenter’s direction in the summer of 1870, were included within an area nearly 2,000 English miles in length by 250 in width, extending from a little beyond the Feroe Islands, lat. 62° 30’ N., to the Strait of Gibraltar, lat. 36° N. The greater part of this belt may be described as CHAP. VIII] THE GULF-STREANM. 857 the eastern border of the North Atlantic fringing Western Europe. A small but very interesting por- tion of it forms the channel between the Froe Tslands and the North of Scotland, one of the chan- nels of communication between the North Atlantic and the North Sea; and a few soundings in shallow water to the east of Shetland are in the shallow North Sea basin. It is evident, therefore, that the ereater part if not the whole of this belt must par- ticipate in the general scheme of distribution of temperature in the North Atlantic, and must owe any peculiarities which its thermal conditions may present to some very general cause. All our temperature observations, except the few taken in the ‘Lightning’ in 1868, were made with thermometers protected from pressure on Professor Miller’s plan, and the thermometers were individually tested by Captain Davis at pressures rising to about three tons to the square inch before they were fur- nished to the vessel; they were also more than once reduced to the freezing-point during the voyage to ascertain that the glass had been in no way distorted. The results may therefore be received with absolute reliance within the limits of: error of observation, which were reduced to a minimum by the care of Captain Calver. A large number of scattered observations, most of which have unfortunately been made with instru- ments which cannot thoroughly be depended upon for accuracy of detail,—the error, however, being probably in the direction of excess of heat,—esta- blished the singular fact that although the tempera- ture of the surface of the sea in equatorial regions 358 THE DEPTHS OF THE SEA. [cHAP, VIII. may reach 30° C., at the greatest depths both in the Atlantic and in the Pacific the temperature is not higher than from 2° to 4° C., sometimes falling at great depths to 0° C. I quote from Mr. Prestwich’s able presidential address to the Geological Society for the year 1871, a table of the most important of these earlier observations in the Atlantic and the 4 a Pacific :'— TEMPERATURES OF THE ATLANTIC. Temperature, Depth Latitude. Longitude. in Observer and Date. Faths. | surface, | Bottom. 42° O'N,. | 34°40°W.| 780 | 16°7°C.| 6°6°C.| Chevalier. . 1837 29 0 34 50 1400 | 24°4 61 5 . . 1837 7 21 20 40 505 | 26°6 2°2 Lenz . . . 1832 A 25 26 6 1006 | 27°0 3°2 Tessan . . 1841 15 38. 23 14 1200 | 25°0 41 os . . 1841 25 10 7 59 E. 886 | 19°6 30 ” . . 1841 29 33 10 57 1051 | 19°1 20 i . . 1841 32 20 43 50 1074 | 21°6 2°4 Lenz . . . 1832 38 12 54 80 W. | 333 | 16°8 30 Tessan . . 1841 TEMPERATURES OF THE Paciric. Temperature, Depth Latitude. Longitude. in Observer and Date. Fath, Surface. Bottom. 51°34 N, | 161°41’ E. | 957 | 11°8°C.| 2°5°C.| Tessan . . 1832 28 52 173 9 600 | 25°5 50 Beechey. . 1828 18 5 174 10 710 | 247 4:8 » + + 1836 4 32 134 24 W.| 2045 | 27°2 17 The ‘Bonite’ 1837 Equator. | 179 34 1000 | 30:0 25 Kotzebue . 1824 21 148. 196 1 916 | 27:2 2°2 Lenz. . . 1834 32 57 176 42 E. 782 | 16°4 54 ae 1834 43 47 80 6 W.| 1066 | 13°0 2°3 Tessan . . 1841 * Address delivered at the Anniversary Meeting of the Geological Society of London on the 17th of February, 1871, by Joseph Prest- wich, F.R.S. Pp. 36, 37. cua. vill. ] THE GULF-STREAM. 859 To these may be added the observations of Lieu- tenant S. P. Lee, of the United States Coast Survey, who, in August 1847, recorded a temperature of 27 CO. below the Gulf-stream at a depth of 1,000 fathoms, lat. 35° 26’ N., long. 73° 12’ W.; and of Lieutenant Dayman, who found the temperature at 1,000 fathoms in lat. 51° N. and long. 40° W. to be — 0°4.C., the surface temperature being 12°5 C. These results are fully borne out by the recent determinations of Captain Shortland, R.N., who observed a temperature of 2°°5 C. in deep water in the Arabian Sea between Aden and Bombay,’ by those of Commander Chimmo, R.N., and Lieutenant Johnson, R.N., who found at various points in the Atlantic a temperature of about 3°9C. at 1,000 fathoms, and a slow decrease from that point to 2,270 fathoms, where the temperature registered by unprotected thermometers was 6”6 C., reduced by the necessary correction for pressure to about 1°6 C.,’ and finally by the temperature determinations of the ‘Porcupine’ expeditions, carefully conducted with protected instruments, but not carried nearer the tropics than the latitude of the Strait of Gibraltar ; and they appear to go far to establish a nearly uni- form temperature for abyssal depths, not far from the freezing-point of fresh water. As it was evident that the low temperature for deep water in tropical regions could not be acquired ‘ Sounding Voyage of H.M.S. ‘Hydra,’ Captain P. F. Shortland. London; 1869. * Soundings and Temperatures in. the Gulf-stream. By Commander = Chimmo, R.N. (Proceedings of the Royal Geographical Society, vol, xiii.) 60 THE DEPTHS OF THE SEA. [cHaP. vill. by contact with the surface of the crust of the earth, the inevitable conclusion seems to have been early arrived at that, if such temperatures existed, they must be due to a general oceanic circulation,— to surface currents of warm water passing towards the poles, and compensating counter-currents of cold water from the poles towards the equator. Hum- boldt states that he showed, in 1812, “that the low temperature of the tropical seas at great depths could only be owing to currents from the poles to the equator ’’? D’Aubuisson, in 1819, also attributed the low temperature of the sea at great depths at or near the equator to the flow of currents from the poles.’ But although the fact of the existence of currents lowering the temperature of deep water in equa- torial regions was admitted by various authorities in physical geography, little light was thrown upon the causes of this circulation. Latterly, the whole subject became obscured by the very general adop- tion of the doctrine already referred to of a perma- nent temperature of 4° C. all over the world beyond a certain depth; and it was not until the publi- cation of Captain Maury’s fascinating book on the ‘ Physical Geography of the Sea’ had given an extra- ordinary stimulus to the study of this department of science, that the question was again raised. It was natural from its geographical position, and from the much greater opportunity which it offered for the accumulation of the almost infinite number 1 Fragments de Géol. et de Climatol. Asiat., 1831. 2 Traité de Géognosie.—Quoted in the Anniversary Address to the Geological Society of London, 1871. cHap, Vu11.] THE GULF-STREAM. 861 of data required for the consideration of such sub- jects, that the basin of the North Atlantic should be selected for investigation, more particularly as peculiarities of climate seemed there to be limited in space, and well defined and even extreme in character. It seems at first somewhat singular that there should be any room for question as to the causes, the sources, and the directions of the ocean currents which traverse the ocean in our immediate neigh- bourhood, and exercise a most important influence on our economy and well-being. The investigation is, however, one of singular difficulty. Some currents are palpable enough, going at a rate and with a force which make it easy to detect them, and even com- paratively easy to gauge their volume and define their path; but it seems that the great movements of the water of the ocean, those which produce the most important results in the transfer of tempera- ture and the modification of climate, are not of this character. These move so slowly that their surface movement is constantly masked by the drift of vari- able winds, and they thus produce no sensible effect upon navigation. The path and limits of such bodies of moving water can only be determined by the use of the thermometer. The equalizing of the temperature of bodies of water in contact with one another and differently heated, by conduction, diffusion, and mixture, is however so slow, that we usually have but little difficulty in distinguishing currents from different sources. Up to the present time little had been done in determining the depth and mass of currents by the 862 THE DEPTIES OF THE SEA. (CHAP. VIII. thermometer, and under-currents were practically unknown; but the limits of surface currents had been traced with considerable precision by observa- tions of the temperature of the surface of the sea, even when the movement was so slow as not to be otherwise perceptible. The amount of heat received directly from the sun may be taken approximately to depend upon latitude only, and this heat is in addition to the heat of the surface water derived from other sources, whatever these may be. Observa- tions of surface temperature accordingly give us the heat derived directly from the sun in the region, and the heat derived from the same source during the passage of the water to the region, in addition to the original heat of the water ; if, therefore, the water of any region be derived from—that is to say, form part of—a movement of water from a polar source, and if the surface water of another area on the same parallel of latitude form part of an equatorial current, although in that particular latitude they receive in both cases the same amount of heat from the sun, there will be a marked difference in their tempera- ture. To take an extreme case; the mean tem- perature of the sea in the month of July off the Hebrides, in -lat. 58° N., in the path of the Gulf stream, is 18° C.; while in the same latitude off the coast of Labrador, in the course of the Labrador current, it is 4°°5 C. The distribution of surface temperature in the North Atlantic is certainly very exceptional. A glance at the chart Pl. VII., representing the general distribution of heat for the month of July, shows that the isothermal lines for that month, instead of ——- = ‘hing fo yyuow ay? 4of pungouaduag fo woynguysyp pouruab ayy puw ‘yadop oy) Burmoys < omunyy YMON °Y? fo pny yooshyg— TIA FLV1g owaP. vit | THE GULF-STREAM. 363 tending in the least to coincide with the parallels of latitude, run up into a series of long loops, some of them continued into the Arctic Sea. The temperature of the bordering land is not affected to any perceptible degree by direct radia- tion from the sea; but it is greatly affected by the temperature of the prevailing winds. Setting aside the still more important point of the equalization of summer and winter temperature, the mean annual temperature of Bergen, lat. 60° 24° N., subject to the ameliorating influence of the prevailing south- west wind blowing over the temperate water of the North Atlantic, is 6°7 C.; while that of Tobolsk, lat. 58° 13’ N., is — 2°4 C. But the temperature of the North Atlantic and its bordering lands is not only raised above that of places on the same parallel of latitude having a ‘continental’ climate, but it is greatly higher than that of places apparently similarly circumstanced to itself in the southern hemisphere. Thus the mean annual temperature of the Féroe Islands, lat. 62° 2'N., is 7°1C., nearly equal to that of the Falkland Islands, lat. 52° S., which is 8°2 C.; and the temperature of Dublin, lat. 53° 21’ N., is 9°°6 C., while that of Port Famine, lat. 53° 8’ §., is 5°38 C. Again, the high temperature of the North Atlantic is not equally distributed, but is very marked in its determination to the north-east coast. Thus the mean annual temperature of Halifax (Nova Scotia), lat. 44° 39’ N., is 62 C., while that of Dublin, lat. 53° 21’ N., is 96 C.; and the temperature of Boston (Mass.), lat. 42° 21’ N., is exactly the same as that of Dublin. 364 THE DEPTHS OF THE SEA. [cHAP. vin. This remarkable diversion of the isothermal lines from their normal direction is admittedly caused by ocean currents affecting the temperature of the surface while conveying the warm tropical water towards the polar regions, whence there is a con- stant counterflow of cold water beneath to supply its place. We thus arrive at the well-known result that the temperature of the sea bathing the north-eastern shores of the North Atlantic is raised greatly above its normal point by currents involving an inter- change of tropical and polar water; and that the lands bordering on the North Atlantic participate in this amelioration of climate by the heat imparted by the water to their prevailing winds. This phenomenon is not confined to the North Atlantic, although from its peculiar configuration and relation to the land that ocean presents the most marked example. A corresponding series of loops, not so well defined, passes southwards along the east coast of South America, and a very marked series occupies the north-eastern angle of the Pacific off the Aleutian Islands and the coast of California. Two principal views have been held as to the causes of the currents in the North Atlantic. One of these, which appears to have been first advanced in a definite form by Captain Maury, and which has received some vague support from Professor Buff, is that the great currents and counter-currents of warm and cold water are due to a circulation in the watery shell of the globe, comparable to the circulation of the atmosphere,—that is to say, caused by tropical heat and evaporation, and arctic cold. cHaP. VIll.] THE GULF-STREAM. 365 It is not easy to understand Captain Maury’s view. He traces all ocean currents to differences in specific gravity. He says: “If we except the tides, and the partial currents of the sea, such as those that may be created by the wind, we may lay it down as a rule that all the currents of the ocean owe their origin to the differences of specific gravity between sea-water at one place and sea-water at another; for wherever there is such a difference, whether it be owing to dif- ference of temperature or to difference of saltness, &c., it is a difference that disturbs equilibrium, and currents are the consequence.”* These differences in specific gravity he attributes to two principal causes ; differences in temperature, and excess of salts produced by evaporation. Captain Maury explains his views as to the first of these causes by an illustra- tion. “Let us now suppose that all the water within the tropics to the depth of one hundred fathoms sud- denly becomes oil. The aqueous equilibrium of the planet would thereby be disturbed, and a general system of currents and counter-currents would be immediately commenced, the oil in an unbroken sheet on the surface running towards the poles, and the water as an under-current towards the equator. The oil is supposed, as it reaches the polar basin, to be re- converted into water, and the water to become oil as it crosses Cancer and Capricorn, rising to the surface in intertropical regions, and returning as before.” “Now, do not the cold water of the north, and the warm water of the gulf made specifically lighter by tropical heat, and which we see actually presenting "The Physical Geography of the Sea, and its Meteorology. By M. T. Maury, LL.D. 366 THE DEPTHS OF THE SEA. (CHAP. VIII. such a system of counter-currents, hold at least, in some degree, the relation of the supposed water and oil,” “There can be no doubt that Maury concludes that the waters in intertropical regions are expanded by heat, and those in polar regions are contracted by cold, and that this tends to produce a surface-current from the equator te the poles, and an under-current from the poles to the equator.”’’ With regard to increased specific gravity produced by excess of salt, Captain Maury says,— “The brine of the ocean is the ley of the earth. From it the sea derives dynamical power, and its cur- rents their main strength.’ ‘One of the purposes which in the grand design it was probably intended to accomplish by leaving the sea salt and not fresh, was to impart to its waters the forces and powers necessary to make their circulation complete.”* ‘ In the present state of our knowledge concerning this wonderful phenomenon (for the Gulf-stream is one of the most marvellous things in the ocean), we can do little more than conjecture. But we have the causes in operation, which we may safely assume are among those concerned in producing the Gulf- stream. One of these is the increased saltness of its water after the trade-winds have been supplied with vapour from it, be it much or little; and the other is the diminished quantum of salt which the 1 Captain Maury, op. cit. 2 On Ocean Currents. Part III. On the Physical Cause of Ocean Currents. By James Croll, of the Geological Survey of Scotland. (Philosophical Magazine, October 1870.) % Captain Maury, op. cit. 4 Ibid. CHAP. VIII.] THE GULF-STREAM. 367 Baltic and the northern seas contain,’”’' “ Now, here we have on one side the Caribbean Sea.and Gulf of Mexico with. their waters of brine; on the other, the great Polar Basin, the Baltic, and the North Sea, the two latter with waters that are but little more than brackish. In one set of these sea-basins the water is heavy, in the other it is light. Between them the ocean intervenes; but water is bound to seek and to maintain its level; and here, therefore, we unmask one of the agents concerned in causing the Gulf-stream.”’ ” As Mr. James Croll has very clearly pointed out, Captain Maury’s two causes tend to neutralize each other. “Now it is perfectly obvious that if difference in saltness is to co-operate with difference in tempera- ture in the production of ocean currents, the saltest waters, and consequently the densest, must be in the polar regions; and the waters least salt, and consequently lightest, must be in equatorial and in- tertropical regions. Were the saltest water at the equator and the freshest at the poles, it would tend to neutralize the effect due to heat, and, instead of producing a current, would simply tend to prevent the existence of the currents which otherwise would result from difference of temperature.” <“ According to both theories it is the differences of density be- tween the equatorial and. polar waters that gives rise to currents; but according to the one theory, the equatorial waters are lighter than the polar, whilst according to the other theory they are heavier than the polar. Either the one theory or the other may 1 Captain Maury, op. cit. 2 Thid. 368 THE DEPTUS OF THE SEA. [cmap. vin, be true, or neither; but it is logically impossible that both of these can, for the simple reason that the waters of the equator cannot at the same time be both lighter and heavier than the water at the poles.” “So long as the two causes continue in action, no current can arise unless the energy of the one cause should happen to exceed that of the other, and even then a current will only exist to the extent by which the strength of the one exceeds that of the other.”’! It seems scarcely: necessary to enter further into detail in reference to Captain Maury’s theory of ocean currents, which is really chiefly remarkable for its ambiguity, and for the pleasant popular style in which it is advocated; since my friend and col- league Dr. Carpenter has latterly brought into great prominence what appears to be a modification of the same view, put in a more definite form. Professor Buff, in his excellent little volume on the Physics of the Earth, speaking of the layer of cold water derived from the Arctic seas which underlies the tropical ocean, and its method of transport, says : “The following well-known experiment clearly illus- trates the manner of the movement. A glass vessel is to be filled with water with which some powder has been mixed, and is then to be heated at bottom. You will soon see, from the motion of the particles of powder, that currents are set up in opposite direc- tions through the water. Warm water rises from the bottom, up through the middle of the vessel, and spreads over the surface; while the colder, and there- fore heavier liquid, falls down at the sides of the + James Croll, op. cit. CHAP. VIII.] THE GULF-STREAM. 369 glass. Currents like these must arise in all water- basins, and even in the oceans if different parts of their surface are unequally heated.’” This is of course a common class-experiment illus- trating convection. It is evidently impossible that movements of ocean water can be produced in this way, for it is well known that everywhere, except under certain exceptional circumstances in the polar basin, the temperature of the sea decreases from the surface to a minimum at the bottom, and tropical heat is applied at the surface only. It is singular that this irrelevant illustration should have been introduced by Professor Buff; for his account of the origin and extension of the Gulf-stream, which may be taken as the type and exponent of ocean currents, is quite consistent with the commonly received opinions. On working up the temperature results of the ‘Porcupine’ expedition of 1869, Dr. Carpenter satis- fied himself that the mass of comparatively warm water, 800 fathoms deep, which we had established as existing, and probably moving in a north-easterly direction, along the west coasts of Britain and the Lusitanian peninsula, could not be an extension of the Gulf-stream, but must be due to a general circu- lation of the waters of the ocean comparable with the circulation of the atmosphere. “The influence of the Gulf-stream proper (meaning 1 Familiar Letters on the Physics of the Earth ; treating of the chief Movements of the Land, the ‘Water, and the Air, and the Forces that give rise to them. By Henry Buff, Professor of Physics in the University of Giessen, Edited by A. W. Hofmann, Ph.D., F.R.S. London: 1851, BSB 370 THE DEPTHS OF THE SEA. [cuap, vit. by this the body of superheated water which issues through the ‘narrows’ from the Gulf of Mexico), if it reaches this locality at all— which is very doubtful —could only affect the most superficial stratum ; and the same may be said of the surtace-drift caused by the prevalence of south-westerly winds, to which some have attributed the phenomena usually ac- counted for by the extension of the Gulf-stream to these regions. And the presence of the body of water which lies between 100 and 600 fathoms depth, and the range of whose temperature is from 48 (8°85 C.) to 42° (5°°5 C.), can scarcely be accounted for on any other hypothesis than that of a great general movement of equatorial water towards the polar area, of which movement the Gulf-stream con- stitutes a peculiar case, modified by local conditions. In like manner the arctic stream which underlies the warm superficial strata in our cold area, con- stitutes a peculiar case, modified by the local condi- tions, to be presently explained, of a great general movement of polar water towards the equatorial area, which depresses the temperature of the deepest parts of the great oceanic basins nearly to the freezing-point.”’ 4 At first Dr. Carpenter appears to have regarded this oceanic circulation as a case of simple convection. «To what, then, is the north-east movement of the warm upper stratum of the North Atlantic attri- butable? I have attempted to show that it is part of a general interchange between polar and equa- torial waters, which is quite independent of any such 1 A Lecture delivered at the Royal Institution, abstracted with the Author's signature in Nature, vol. i. p. 488 (March 10th, 1870). CHAP. VIII.] LHE GULF-STREAM. 37l local accidents as those which produce the Gulf- stream proper, and which gives movement to a much larger and deeper body of water than the latter can affect. The evidence of such an interchange is two- fold—that of physical theory, and that of actual observation. Such a movement must take place, as was long since pointed out by Professor Buff, when- ever an extended body of water is heated at one part and cooled at another ; it is made use of in the warm- ing of buildings by the hot-water apparatus, and it was admirably displayed at the Royal Institution a few months since in the following experiment kindly prepared for me by Dr. Odling.” Dr. Carpenter then repeats Professor Buff’s convection experiment, the heat being applied by a steam jet introduced vertically at one end of a narrow glass trough while a block of ice was wedged into the other end. “Thus a circulation was shown to be maintained in the trough by the application of heat at one of its extremities and of cold at the other, the heated water flowing along the surface from the warm to the cold end, and the cooled water flowing along the bottom from the cold to the warm end; just as it has been maintained that equatorial water streams on the surface towards the poles, and that polar water returns along the bottom towards the equator, if the movement be not interfered with by interposed obstacles, or prevented by antagonistic currents arising from local peculiarities.’’! That such a movement cannot take place on this hypothesis has been already shown; and Dr. Car- ‘ The Gulf-stream. A letter from Dr. Carpenter to the Editor of Nature, dated Gibraltar, August 11th, 1870. (Nature, vol. ii. p. 334.) BB2 372 THE DEPTHS OF THE SEA. [onar. vin. penter in a lecture to the Royal Geographical Society, in an illustration drawn from two supposed basins, one under equatorial conditions and the other under polar, connected by a strait,’ says: ‘The effect of surface-heat upon the water of the tropical basin will be for the most part limited to its uppermost stratum, and may here be practically disregarded. But the effect of surface-cold upon the water of the polar basin will be to reduce the temperature of its whole mass below the freezing-point of fresh water, the surface stratum sinking as it is cooled, by virtue of its diminished bulk and increased density, and being replaced by water not yet cooled to the same degree. The warmer water will not come up from below, but will be drawn into the basin from the surface of the surrounding area; and since what is thus drawn away must be supplied from a yet greater distance, the continual cooling of the surface stratum in the polar basin will cause a ‘set’ of water towards it to be propagated backwards through the whole inter- vening ocean in connection with it, until it reaches the tropical area.’”’ And further on in the same address: “‘It is seen that the application of cold at the surface is precisely equivalent as a moving power to that application of heat at the bottom by which the circulation of water is sustained in every heating apparatus that makes use of it.’ No doubt the application of cold to the surface of a mass of water previously at the same temperature throughout, would 1 On the Gibraltar Current, the Gulf-stream, and the general Oceanic Circulation. By Dr. W. B. Carpenter, F.R.S. Reprinted from the Proceedings of the Royal Geographical Society of London, 1870, CHAP. VIII] THE GULF-STREANM. 373 have the same effect as the application of heat to the bottom, and in either case we should have an instance of simple convection, the warmer under- water rising through a colder upper layer; but that is not what we have in the polar sea; for the temperature of the arctic sea gradually sinks from a few fathoms beneath the surface to a minimum temperature, and consequent maximum density, at the bottom. Therefore in this case the application of cold at the surface is not equivalent to the appli- cation of heat to the bottom in a hot-water heating apparatus, and Dr. Carpenter has shown that he is aware of this by requiring the backward propagation of a surface-current. That a certain effect in increase of specific gravity must be produced by the cooling of the surface film of the arctic ocean there seems to be little doubt; but the area of maximum effect is very limited, and during the long arctic winter the greater part of that area is protected by a thick layer of ice, one of the worst possible conductors. It certainly appears to me that this cause is totally inadequate to induce a powerful current of great depth, six. thousand miles long and several thousand miles in width, the effect which Dr. Car- penter attributes to it. During the summer of 1870, and afterwards in 1871, Dr. Carpenter made a series of observations on the current in the Strait of Gibraltar. The existence of an under-current out of the Mediterranean was considered to be established by these observations, and the conclusions arrived at as to its cause did not differ materially from those already very generally 374 THE DEPTHS OF THE SEd. [CHAP. VIL accepted. Dr. Carpenter believes, however, that the conditions in the Strait of Gibraltar and in the Baltic Sound aptly illustrate the general circulation in the ocean, and confirm his views. I quote from the general summary of Dr. Car. penter’s address to the Geographical Society :— “The application of the foregoing principles to the particular cases discussed in the paper is as follows :— “VIII.—A vertical circulation is maintained in the Strait of Gibraltar by the excess of evaporation in the Mediterranean over the amount of fresh water returned into its basin, which at the same time lowers its level and increases its density; so that the surface inflow of salt water which restores its level (exceeding by the weight of salt contained in it the weight of fresh water which has passed off by evaporation) disturbs the equilibrium and pro- duces a deep outflow, which in its turn lowers the level. The same may be assumed to be the case in the Strait of Babelmandeb. «* [X.—A vertical circulation is maintained in the Baltic Sound by an excess in the influx of fresh water into the Baltic; which at the same time raises its level and diminishes its density, so as to produce a surface outflow, leaving the Baltic column the lighter of the two, so that a deep inflow must take place to restore the equilibrium. The same may be assumed to be the case in the Bosphorus and Dardanelles. ‘*X.—A vertical circulation must, on the same principles, be maintained between polar and equa- torial waters by the difference of their temperatures : CHAP. VILL] THE GULF-STREAM. 375 the level of the polar water being reduced, and its density increased by the surface-cold to which it is subjected, whilst a downward motion is also imparted to each stratum successively exposed to it; and the level of equatorial water being raised and its density diminished by the surface-heat to which it is exposed. (The first of these agencies is by far the more effec- tive, since it extends to the whole depth of the water, whilst the second only affects, in any considerable degree, the superficial stratum.) Thus a movement will be imparted to the upper stratum of oceanic water from the equator towards the poles, whilst a movement will be imparted to the deeper stratum from the poles towards the equator.” It seems to me that the doctrine here propounded by my distinguished colleague, if I understand it aright, is open to the objection to which I have already referred in connection with the speculations of Captain Maury. If the currents flow in the direction and with the permanence accepted by Dr. Carpenter in the Strait of Gibraltar and in the Baltic Sound, if their flow and its direction be due to the causes to which Dr. Carpenter attributes them, and if there be any analogy whatever between the conditions of equi- librium of these inland seas and that of the outer ocean,—none of which propositions appear to me at all satisfactorily proved,—I should think that the vast equatorial region, the path of the trade-winds and the belt of vertical solar radiation, must, so far as eva- poration is concerned, resemble, or rather greatly exaggerate, the conditions of the Mediterranean. The consequent accumulation of salt,—through the whole 376 THE DEPTHS OF THE SEA. [cHap. viii. depth of course, the brine sinking downwards,—must greatly outweigh (I give this as what Petermann would call a gratuitous speculation) the slight ex- pansion caused by the heating of the surface layer. The more restricted arctic basin on the other hand, as was long ago pointed out by Capt. Maury, partici- pates to a certain extent in the characteristics of the Baltic; and I am greatly mistaken if the low specific gravity of the polar sea, the result of the condensation and precipitation of vapour evaporated from the intertropical area, do not fully counter- balance the contraction of the superficial film by arctic cold. The North Atlantic ocean bears a_ proportion in depth to the mass of the earth considerably less than that of the paper covering an eighteen- inch globe to that of the globe it covers, while the film heated by direct solar radiation may be represented by its surface coating of varnish, and is not actually thicker than the height of St. Paul’s. Physicists seem to find a difficulty in giving us the amount of palpable effect in pro- ducing currents in this shell of water, six thousand miles in length by three thousand in width and ‘two miles in thickness, which may be due to causes such as those relied upon by Dr. Carpenter, acting under the peculiar circumstances and to the amount in which we find them in nature; and probably we are not yet in a position to give them sufficient data to enable them todoso. Mr. Croll, a good authority in such matters, has attempted to make some calcu- tions, and comes to the conclusion that none of them are sufficient to overcome the friction of water and to CHAP. VIIl.] THE GULF-STREAM. O77 produce any current whatever; but in this view he does not certainly receive universal support. I am myself inclined to believe that in a great body of salt water at different temperatures, with unequal amounts of evaporation, under varying barometric pressures, and subject to the drift of variable winds, currents of all kinds, great and small, variable and more or less permanent, must be set up;* but the probable result appears to be reduced to a minimum when we find that causes, themselves of doubtful efficiency, actually antagonize one another; and that we are obliged to trust for the final effect to the amount by which the least feeble of these exceeds the others in strength. Speaking in the total ab- sence of all reliable data, it is my general impres- sion that, if we were to set aside all other agencies, and to trust for an oceanic circulation to those con- ditions only which are relied upon by Dr. Carpenter, if there were any general circulation at all, which seems very problematical, the odds are rather in favour of a warm under-current travelling north- wards by virtue of its excess of salt, balanced by a surface return-current of fresher though colder arctic water. With regard, then, to this question of a general circulation caused by difference in specific gravity, for the present I cordially endorse the opinion ex- ‘pressed by the late Sir John Herschel in a cautious + James Croll, op. cit. 2 On the Distribution of Temperatures in the North Atlantic. An Address delivered to the Meteorological Society of Scotland at the General Meeting of the Society July 5th, 1871, by Professor Wyville Thomson. 378 THE DEPTHS OF THE SEA. [cHAP. VILI. and excellent letter addressed to Dr. Carpenter—a letter which there is no impropriety in my quoting in full as it is already in print, and which has a special interest as being probably one of the last written by Sir John Herschel on scientific subjects :— *“CoLLINGWooD, April 9th, 1871. “My DEAR Sir—Many thanks for your paper on the Gib- raltar current and the Gulf-stream. Assuredly, after well con- sidering all you say, as well as the common sense of the matter, and the experience of our hot-water circulation pipes in our greenhouses, &c., there is no refusing to admit that an oceanic circulation of some sort must arise from mere heat, cold, and evaporation, as ver cause, and you have brought forward with singular emphasis the more powerful action of the polar cold, or rather the more intense action, as its maximum effect is limited to a much smaller area than that of the maximum of equatorial heat. “The action of the trade and counter-trade winds, in like manner, cannot be ignored; and henceforward the question of ocean currents will have to be studied under a twofold point of view. The wind-currents, however, are of easier investigation : all the causes lie on the surface; none of the agencies escape our notice; the configuration of coasts, which mainly determines their direction, is patent to sight. It is otherwise with the other class of movements. They take place in the depths of the ocean; and their movements and directions and channels of concentra- tion are limited to the configuration of the sea-bottom, which has to be studied over its entire surface by the very imperfect method of sounding. “Tam glad you succeeded in getting specimens of Mediter- ranean water near the place of the presumed salt spring of Smyth and Wollaston, making it clear that the whole affair must have arisen from some accidental substitution of one bottle for another, or from evaporation. I never put any hearty faith in it. CHAP. VILL] THE GULF-STREAM. 379 “So, after all, there is an under-current setting outwards in the Straits of Gibraltar. = “Repeating my thanks for this interesting memoir, believe me, dear Sir, “Yours very truly, “J. F. W. HERSCHEL. “ Dr. W. B. Carpenter.” } The second view, supported by Dr. Petermann of Gotha, and by most of the leading authorities in physical geography in Germany and Northern Europe, and strongly urged by the late Sir John Herschel in his ‘Outlines of Physical Geography’ published in the year 1846, attributes nearly the whole of the sensible phenomena of heat-distribution in the North Atlantic to the Gulf-stream, and to the arctic return-curreuts which are induced by the removal of tropical water towards the polar regions by the Gulf-stream. If we for a moment admit that to the Gulf-stream is due almost exclusively the singular advantage in climate which the eastern borders of the North Atlantic possess over the western, the origin of this great current, its extent and direction, and the nature and amount of its influence, become questions of surpassing interest. Before considering these, however, it will be well to define what is here meant by the term ‘Gulf- stream,’ for even on this point there has been a good deal of misconception. I mean by the Gulf-stream that mass of heated water which pours from the Strait of Florida across the North Atlantic, and likewise a wider but less definite warm current, evidently forming part of the Same great movement of water, which curves north- 1 Nature, vol. iv. p. 71 380 THE DEPTHS OF THE SEA. [cHAP, VIII. wards to the eastward of the West Indian Islands. I am myself inclined, without hesitation, to regard this stream as simply the reflux of the equatorial current, added to no doubt during its north-easterly course, by the surface-drift of the anti-trades which follows in the main the same direction. The scope and limit of the Gulf-stream will be better understood if we inquire in the first place into its origin and cause. As is well known,—in two bands, one to the north and the other to the south of the equator,—the north-east and south-east trade- winds, reduced to meridional directions by the east- ward frictional'impulse of the earth’s rotation, drive before them a magnificent surface current of hot water 4,000 miles long by 450 miles broad at an average rate of thirty miles a day. Off the coast of Africa near its starting-point to the south of the Islands of St. Thomas and Anna Bon, this ‘ Equa- torial Current’ has a speed of forty miles in the twenty-four hours, and a temperature of 23° C. Increasing quickly in bulk, and spreading out more and more on both sides of the equator, it flows rapidly due west towards the coast of South America. At the eastern point of South America, Cape St. Roque, the equatorial current splits into two, and one portion trends southwards to deflect the isotherms of 21°, 15°5, 10°, and 4°°5 C. into loops upon our maps, thus carrying a scrap of comfort to the Falkland Islands and Cape Hoorn; while the northern portion follows the north-east coast of South America, gaining continually in temperature under the influence of the tropical sun. Its speed has now increased to sixty- eight miles in twenty-four hours, and by the union CHAP. VIII] THE GULF-STREAM. B81 with it of the waters of the river Amazon, it rises to one hundred miles (6°5 feet in a second), but it soon falls off again when it gets into the Caribbean sea. Flowing slowly through the whole length of this sea, it reaches the Gulf of Mexico through the Strait of Yucatan, when a part of it sweeps immediately round Cuba; but the main stream “having made the circuit of the Gulf of Mexico, passes through the Strait of Florida; thence it issues as the ‘ Gulf-stream’ in a majestic current upwards of thirty miles broad, two thousand two hundred feet deep, with an average velocity of four miles an hour, and a temperature of 86° Fahr. (30° C).”! The hot water pours from the strait with a decided though slight north-easterly impulse on account of its great initial velocity. Mr. Croll calculates the Gulf-stream as equal to a stream of water fifty miles broad and a thousand feet deep flowing at a rate of four miles an hour; consequently conveying 5,575,680,000,000 cubic feet of water per hour, or 183,816,320,000,000 cubic feet per day. This mass of water has a mean temperature of 18°C. as it passes out of the gulf, and on its northern journey it is cooled down to 4°°5, thus losing heat to the amount of 18°5C, The total quantity of heat therefore trans- ferred from the equatorial regions per day amounts to something like 154,959,300,000,000,000,000 foot- pounds.” This is nearly equal to the whole of the heat ’ Physical Geography. From the ‘Encyclopedia Britannica.’ By Sir John F, W. Herschel, Bart., K.H.P. Edinburgh, 1861, p. 49. ? On Ocean Currents. By James Croll, of the Geological Survey of Scutland. Part I. Ocean Currents in relation to the Distribution of Heat over the Globe (Philosophical Magazine. February 1870.) 382 THE DEPTHS OF THE SEA. [CHAP, VIII. received from the sun by the Arctic regions, and, reduced by a half to avoid all possibility of exaggera- tion, it is still equal to one-fifth of the whole amount received from the sun by the entire area of the North Atlantic. The Gulf-stream, as it issues from the Strait of Florida and expands into the ocean on its north- ward course, is probably the most glorious natural phenomenon on the face of the earth. The water is of a clear crystalline transparency and an intense blue, and long after it has passed into the open sea it keeps itself apart, easily distinguished by its warmth, its colour, and its clearness; and with its edges so sharply defined that a ship may have her stem in the clear blue stream while her stern is still in the common water of the ocean. «The dynamics of the Gulf-stream have of late, in the work of Lieutenant Maury already mentioned, been made the subject of much (we cannot but think misplaced) wonder, as if there could be any possible ground for doubting that it owes its origin entirely to the trade-winds.”’! Setting aside the wider ques- tion of the possibility of a general oceanic circulation arising from heat, cold, and evaporation, I believe that Captain Maury and Dr. Carpenter are the only authorities who of late years have disputed this source of the current which we see, and can gauge and measure as it passes out of the Strait of Florida; for it is scarcely necessary to refer to the earlier speculations that it is caused by the Mississippi river, or that it flows downwards by gravitation from a ‘head’ of water produced by the trade-winds in the Caribbean sea. * Herschel, op. cit. p. 51. cuaP, VIII] THE GULF-STREAM. 383 Captain Maury writes! that “the dynamical force that calls forth the Gulf-stream is to be found in the difference as to specific gravity of intertropical and polar waters.” “The dynamical forces which are expressed by the Gulfstream may with as much pro- priety be said to reside in those northern waters as in the West India seas: for on one side we have the Caribbean sea and Gulf of Mexico with their waters of brine; on the other the great polar basin, the Baltic, and the North Sea, the two latter with waters which are little more than brackish. In one set of these sea-basins the water is heavy; in the other it is light. Between them the ocean intervenes; but water is bound to seek and to maintain its level; and here, therefore, we unmask one of those agents conccrned in causing the Gulf-stream. What is the power of this agent? Is it greater than that of other agents ? and how much? We cannot say how much; we only know it is one of the chief agents concerned. More- over, speculate as we may as to all the agencies con- cerned in collecting these waters, that have supplied the trade-winds with vapour, into the Caribbean Sea, and then in driving them across the Atlantic, we are forced to conclude that the salt which the trade-wind vapour leaves behind it in the tropics has to be con- veyed away from the trade-wind region, to be mixed up again in due proportion with the other water of the sea—the Baltic Sea and the Arctic Ocean included —and that these are some of the waters, at: least, which we see running off through the Gulf-stream. To convey them away is doubtless one of the offices which in the economy of the ocean has been assigned ? Maury’s Physical Geography of the Sea, op. cit. B84 THE DEPTHS OF THE SEA. [cHap. viur. to it. But as for the seat of the forces which put and keep the Gulf-stream in motion, theorists may place them exclusively on one side of the ocean with as much philosophical propriety as on the other. Its waters find their way into the North Sea and Arctic Ocean by virtue of their specific gravity, while water thence, to take their place, is, by virtue of its specific gravity and by counter-currents, carried back into the gulf. The dynamical force which causes the Gulf-stream may therefore be said to reside both in the polar and in the intertropical waters of the Atlantic.’ According to this view, the tropical water finds its way on account of its greater weight towards the poles, while the polar water, owing to its less weight, moves southwards to replace it. The general result would be of course a system of warm under- and cold surface-currents, and these we do not find. I merely quote the passage as a curious illustration of the adage that on most questions a good deal can be said on both sides. We have already considered the doctrine of a general oceanic circulation, which has been so strongly ad- vocated of late by Dr. Carpenter, and I have merely to advert in this place to the bearing which that doctrine has upon our views as to the origin of the Gulf-stream ; its bearings on the extension and dis- tribution of the current will be discussed hereafter. As already stated, Dr. Carpenter attributes all the great movements of ocean water to a general con- vective circulation, and of this general circulation he regards the Gulf-stream as a peculiarly modi- fied case. In the passage already quoted (p. 370) of CHAP. VIII} THE GULF-STREAM. 885 his address to the Royal Institution, Dr. Carpenter states, that ‘the Gulf-stream constitutes a peculiar case, modified by local conditions,” of “a great general movement of equatorial water towards the polar area.”’ I confess I feel myself compelled to take a totally different view. It seems to me that the Gulf-stream is the one natural physical pheno- menon on the surface of the earth whose origin and principal cause, the drift of the trade-winds, can be most clearly and easily traced. The further progress and extension of the Gulf- stream through the North Atlantic in relation to influence upon climate has been, however, a fruitful source of controversy. The first part of its course, after leaving the strait, is sufficiently evident, for its water long remains conspicuously different in colour and temperature from that of the ocean, and a current having a marked effect on naviga- tion is long perceptible in the peeuliar Gulf-stream water. ‘Narrow at first, it flows round the penin- sula of Florida, and, with a speed of about 70 or 80 miles, follows the coast at first in a due north, afterwards in a north-east direetion. At the lati- tude of Washington it leaves the North American coast altogether, keeping its north-eastward course ; and to the south of the St. George’s and New- foundland Banks it spreads its waters more and more over the Atlantic Ocean, as far as the Acores. At these islands a part of it turns southwards again towards the African coast. The Gulf-stream has, so long as its waters are kept together along the American coast, a temperature of 26°6 C.; but, even under north latitude 36°, Sabine found that cc 386 THE DEPTHS OF TEE SEA. [cuap. vin. 23°3 C. at the beginning of December, while the sea-water beyond the stream showed only 16°9 C. Under north latitude 40—41° the water is, accord- ing to Humboldt, at 22°5 C. within, and 17°5 C. without the stream.” ! The Gulf-stream off the coast of North America has been most carefully examined by the officers of the United States Coast Survey, at first under the superintendence of Professor Bache, and latterly under the direction of the present able head of the bureau, Professor Pierce. In 1860 Professor Bache published an account of the general result.? Four- teen sections through the Gulf-stream had been care- fully surveyed at intervals of about 100 miles along the coast—the first almost within the Gulf of Mexico, from Fortingas to Havana, and the last off Cape Cod, lat. 41° N., where the stream loses all parallel- ism with the American coast and trends to the east- ward. These sections fully illustrate the leading phenomena during this earlier part of its course of this wonderful current, which Professor Bache well characterizes as “the great hydrographic feature of the United States.” Opposite Fortingas, passing along the Cuban coast, the stream is unbroken and the current feeble; the temperature at the surface is about 26°7C. Issuing from the Strait of Bemini the current is turned nearly directly northwards by the form of the land; 1 Professor Buff, op. cit. p. 199. 2 Lecture on the Gulfstream, prepared at the request of the American Association for the Advancement of Science, by A. D. Bache, Superintendent U.S. Coast Survey. From the American Journal of Science and Arts, vol. xxx. November 1860. CHAP, VII] THE GULF-STREAM., 887 a little to the north of the strait, the rate is from three to five miles an hour. The depth is only 325 fathoms, and the bottom, which in the Strait of Florida was a simple slope and counter-slope, is now corrugated. The surface temperature is about 26°5C., while the bottom temperature is 4°°5; so that in the moderate depth of 325 fathoms the equa- torial current above and the polar counter-current beneath have room to pass one another, the current from the north being evidently tempered consider- ably by mixture. North of Mosquito inlet the stream trends to the eastward of north, and off St. Augustine it has a decided set to the eastward Between St. Augustine and Cape Hatteras the set of the stream and the trend of the coast differ but little, making 5° of easting in 5° of northing. At Hatteras it curves to the northward, and then runs easterly. In the latitude of Cape Charles it turns quite to the eastward, having a velocity of from a mile to a mile and a half in the hour. A brief account of one of the sections will best explain the general phenomena of the stream off the coast of America. I will take the section following a line at right angles to the coast off Sandy Hook. From the shore out, for a distance of about 250 miles, the surface temperature gradually rises from 21° to 24° C.; at 10 fathoms it rises from 19° to 22° C.; and at 20 fathoms it maintains, with a few irregu- larities, a temperature of 19°C. throughout the whole Space; while at 100, 200, 300, and 400 fathoms it maintains in like manner the respective temperatures of 8°8, 5°7, 4°5, and 2°5C. ‘This space is therefore occupied by cold water, and observation has sufli- cc2 388 THE DEPTHS OF THE SEA. [cHap. Vurt. ciently proved that the low temperature is due to a branch of the Labrador current creeping down along the coast in a direction opposite to that of the Gulfstream. In the Strait of Florida this cold stream divides—one portion of it passing under the hot Gulf-stream water into the Gulf of Mexico, while the remainder courses round the western end of Cuba. 240 miles from the shore the whole mass of water takes a sudden rise of about 10°C. within 25 miles, a rise affecting nearly equally the water at all depths, and thus producing the singular pheno- menon of two masses of water in contact—one passing slowly southwards, and the other more rapidly northwards, at widely different temperatures at the same levels. This abutting of the side of the cold current against that of the Gulf-stream is so abrupt that it has been aptly called by Lieutenant George M. Bache the ‘ Cold wall.’ Passing the cold wall we reach the Gult-stream, presenting all its special characters of colour and transparency and of temperature. In the section which we have chosen as an example, upwards of three hundred miles in length, the surface temperature is about 26°5 C., but the heat is not uniform across the stream, for we find that throughout its entire length, as far south as the Cape Canaveral section, the stream is broken up into longitudinal alternating bands of warmer and cooler water. Off Sandy Hook, beyond the cold wall, the stream rises to a maximum of 27°8C., and this warm band extends for about 60 miles. The temperature then falls to a minimum of 26°°5C., which it retains for about 80 miles, when a second maximum of 27°4 succeeds, which includes CHAP. VIII. ] THE GULF-STREAM, 8389 the axis of the Gulf-stream, and is about 170 miles wide. This is followed by a second minimum of 25°5 C., and this by a third maximum, when the bands become indistinct, It is singular that the minimum bands correspond with valley-like depres- sions in the bottom, which follow in succession the outline of the coast and lodge dezp southward exten- sions of the polar indraught. The last section of the Gulf-stream surveyed by the American Hydrographers extends in a south- easterly direction from Cape Cod, lat. 41° N., and traces the Gulf-stream, still broken up by its bands of unequal temperature, spreading directly eastward across the Atlantic; its velocity has, however, now become inconsiderable, and its limits are best traced by the thermometer. The course of the Gulf-stream beyond this point has given rise to much discussion. I again quote Professor Buff for what may be regarded as the view most generally received among Physical Geo- graphers :— “A great part of the warm water is carried partly by its own motion, but chiefly by the prevailing west and north-west winds, towards the coasts of Europe and even beyond Spitzbergen and Nova Zembla; and thus a part of the heat of the south reaches far into the Arctic Ocean. Hence, on the north coast of the old Continent, we always find driftwood from the southern regions, and on this side the Arctic Ocean remains free from ice during a great part of the year, even as far up as 80° north latitude; while on the opposite coast (of Greenland) the ice is not quite thawed even in summer.” The two forces invoked 390 THE DEPTHS OF THE SEA. (CHAP. VIII. by Professor Buff to perform the work are thus the vis a tergo of the trade-wind drift, and the direct driving power of the anti-trades, producing what has been called the anti-trade drift. This is quite in accordance with the views here advocated. The proportion in which these two forces act, it is un- doubtedly impossible in the present state of our knowledge to determine. My. A. G. Findlay, a high authority on all hydro- graphic matters, read a paper on the Gulf-stream before the Royal Geographical Society, reported in the 13th volume of the Proceedings of the Society. Mr. Findlay, while admitting that the temperature of north-eastern Europe is abnormally ameliorated by a surface-current of the warm water of the Atlantic which reaches it, contends that the Gulf-stream proper, that is to say the water injected, as it were, into the Atlantic through the Strait of Florida by the impulse of the trade-winds, becomes entirely thinned out, dissipated, and lost, opposite the Newfoundland banks about lat. 45° N. The warm water of the southern portion of the North Atlantic basin is still carried northwards; but Mr. Findlay attributes this movement solely to the anti-trades—the south-west winds—which by their prevalence keep up a balance of progress in a north-easterly direction in the surface layer of the water. Dr. Carpenter entertains a very strong opinion that the dispersion of the Gulf-stream may be affirmed to be complete in about lat. 45° N. and long. 35° W. Dr. Carpenter admits the accuracy of the projection of the isotherms on the maps of Berghaus, Dové Petermann, and Keith Johnston, and he admits like- CHAP. VIL] THE GULF-STREAM. 891 wise the conclusion that the abnormal mildness of the climate on the north-western coast of Europe is due to a movement of equatorial water in a north-easterly direction. “What I question is the correctness of the doctrine that the north-east flow is an extension or prolongation of the Gulfstream, still driven on by the vis a tergo of the trade-winds-—a doctrine which (greatly to my surprise) has been adopted and defended by my colleague Professor Wyville Thom- son. But while these authorities attribute the whole or nearly the whole of this flow to the true Gulf- stream, J regard a large part, if not the whole, of that which takes place along our own western coast, and passes north and north-east between Iceland and Norway towards Spitzbergen, as quite independent of that agency; so that it would continue if the North and South American continents were so com- pletely disunited that the equatorial currents would be driven straight onwards by the trade-winds into the Pacific Ocean, instead of being embayed in the Gulf of Mexico and driven out in a north-east direc- tion through the ‘ narrows’ off Cape Florida.’ Dr. Carpenter does not mean by this to endorse Mr. Findlay’s opinion that the movement beyond the 45th parallel of latitude is due solely to the drift of the anti-trades; he says, “‘On the view I advocate, the north-easterly flow is regarded as due to the vis a fronte originating in the action of cold upon the water of the polar area, whereby its level is always tending to depression.”? The amelioration of the climate of north-western Europe is thus * Dr. Carpenter : Proceedings of the Royal Geographical Society for 1870, op. cit. 2 Op. cit. 392 THE DEPTHS OF THE SEA. [cHap. vilr. caused by a ‘modified case’ of the general oceanic circulation, and neither by the Gulf-stream nor by the anti-trade drift. Although there are, up to the present time, very few trustworthy observations of deep-sea tempera- tures, the surface temperature of the North Atlantic has been investigated with considerable care. The general character of the isothermal lines with their singular loop-like northern deflections, has long been familiar through the temperature charts of the geographers already quoted, and of late years a pro- digious amount of data have been accumulated both abroad and by our own Admiralty and Meteoro- logical Department. In 1870, Dr. Petermann, of Gotha, published! an extremely valuable series of temperature charts, embodying the results of the reduction of upwards of 100,000 observations, derived chiefly from the following sources :— 1. From the wind and.current charts of Lieu- tenant Maury, embodying about 30,000 distinct temperature observations. 2. From 50,000 observations made by Dutch sea- captains, and published by the Government of the Netherlands. 3. From the journal of the Cunard steamers be- tween Liverpool and New York, and of the steamers of the Montreal Company between Glasgow and Belleisle. 4, From the data collected by the secretary of the * Der Golf-Strom und Standpunkt der thermometrischen Kenntniss des Nord-Atlantischen Oceans und Landgebietes im Jahre 1870. Justus Perthe’s ‘Geographische Mittheilungen,’ Band 16. Gotha, 1870, CHAP. VIII.] THE GUILF-STREAM. 393 Scottish Meteorological Society, Mr. Buchan, with regard to the temperature of the sea on the coasts of Scotland. 5. From the publications of the Norwegian Insti- tute on sea-temperatures between Norway, Scotland, and Iceland. 6. From the data furnished by the Danish Rear- Admiral Irminger on sea-temperature between Den- mark and the Danish settlements in Greenland. 7. From the observations made by Earl Dufferin on board his yacht ‘Foam’ between Scotland, Ice- land, Spitzbergen, and Norway. And finally, from the recent observations collected by the English, Swedish, German, and Russian ex- peditions to the arctic regions and towards the North Pole. Dr. Petermann has devoted the special attention of a great part of his life to the distribution of heat on the surface of the ocean, and the accuracy and con- scientiousness of his work in every detail are beyond the shadow of a doubt. Plate VII. is in the main copied from his charts, with a few modifications and additions derived from additional data. The remark- able diversion of the isothermal lines from their normal course is undoubtedly caused by surface ocean- currents conveving warm tropical water towards the polar regions. This is no matter of speculation, for the current is in many places perceptible through its effect on navigation, and the path of the warm water may be traced by dipping the thermometer into it and noting its temperature. In the North Atlantic every curve of equal tem- perature, whether for the summer, for the winter, for 394 THE DEPTHS OF THE SEA. [cmap, vin. a single month, or for the whole year, instantly declares itself as one of a system of curves which are referred to the Strait of Florida as a source of heat, and the flow of warm water may be traced in a continuous stream, indicated when its movement can no longer be observed by its form,—fanning out from the neighbourhood of the Strait across the Atlantic, skirting the coasts of France, Britain, and Scandinavia, rounding the North Cape and passing the White Sea and the Sea of Kari, bathing the western shores of Novaja Semla and Spitzbergen, and finally coursing round the coast of Siberia, a trace of it still remaining to find its way through the narrow and shallow Behring’s Strait into the North Pacific (see Plate VIT.). Now, it seems to me that if we had only these curves upon the chart, deduced from an almost in- finite number of observations which are themselves merely laboriously multiplied corroborations of many previous ones, without having any clue to their rationale, we should be compelled to admit that whatever might be the amount and distribution of heat derived from a general oceanic circulation,— whether produced by the prevailing winds of the region, by convection, by unequal barometric pres- sure, by tropical heat, or by arctic cold,—the Gulf- stream, the majestic stream of warm water whose course is indicated by the deflections of the isother- mal lines, is sufficiently powerful to mask all the rest, and, broadly speaking, to produce of itself all the abnormal thermal phenomena. The deep-sea temperatures taken in the ‘ Porcu- pine’ have an important bearing upon this question, CHAP. VIIT.] THE GULF-STREAM. 395 since they give us the depth and volume of the mass of water which is heated above its normal tempera- ture, and which we must regard as the softener of the winds blowing on the coasts of Europe. Refer- ring to Fig. 60, in the Bay of Biscay, after passing through a shallow band superheated by direct radia- tion, a zone of warm water extends to the depth of 800 fathoms, succeeded by cold water to a depth of nearly two miles. In the Rockall channel (Fig. 59) the warm layer has nearly the same thickness, and the cold underlying water is 500 fathoms deep. Off the Butt of the Lews (Fig. 56) the bottom tem- perature is 5°2 C. at 767 fathoms, so that there the warm layer evidently reaches to the bottom. In the Féroe channel (Fig. 55) the warm water forms a surface layer, and the cold water underlies it, commencing at a depth of 200 fathoms,—567 fathoms above the level of the bottom of the warm water off the Butt of the Lews. The cold water abuts against the warm—there is no barrier between them. Part of the warm water flows over the cold indraught, and forms the upper layer in the Féroe channel. What prevents the cold water from slipping, by virtue of its greater weight, under the warm water off the Butt of the Lews? It is quite evident that there must be some force at work keeping the warm water in that particular position, or, if it be moving, compelling it to follow that particular course. The comparatively high tem- perature from 100 fathoms to 900 fathoms I have always attributed to the northern accumulation of the water of the Gulf-stream. The amount of heat derived directly from the sun by the water as it 396 THE DEPTHS OF THE SEA. (cmap. vil. passes through any particular region, must be re- garded, as I have already said, as depending almost entirely upon latitude. Taking this into account, the surface temperatures in what we were in the habit of calling the ‘warm area’ coincided precisely with Petermann’s curves indicating the northward path of the Gulf-stream. I extract the following from a letter dated 23rd September, 1872, from Professor H. Mohn, director of the Norwegian Meteorological Institute at Christiania, to Mr. Buchan, the excellent secretary of the Scottish Meteorological Society :—‘“I have this summer got some deep-sea temperatures which may be of general interest for our climate. In the Throndhjems-fjord I found 16°°5 C. on the surface, and from 50 fathoms to the bottom (200 fathoms) a very uniform tempera- ture of 6°5 C. in one place, and 6° OC. in another place further in. In the Sceguefjord I found 16° C. on the surface, and 6°5 C. constantly from 10 to 700 fathoms. Between Iceland and Féroe, Lieu- tenant Miller, commander of the Bergen and Iceland steamer, has found this summer 8° C. at the bottom in 300 fathoms. This proves that the Gulf-stream water fills the whole of the channel, contrary to what is the case in the Fééroe-Shetland channel, where there is ice-cold water in a depth of 300 fathoms.”” The facts here mentioned are very important, and entirely confirm our results; but my chief object in giving the quotation is to show the unhesitating way in which the explanation which attributes the high temperature of the sea on the Scandinavian coast to the Gulf-stream is adopted by those best qualified to form an opinion. CHAP. VII] THE GULF-STREAM. 397 The North Atlantic and Arctic seas form together a cul de sac closed to the northward, for there is practically no passage for a body of water through Behring’s Strait. While, therefore, a large portion of the water, finding no free outlet towards the north-east, turns southward at the Acores, the re- mainder, instead of thinning off, has rather a ten- dency to accumulate against the coasts bounding the northern portions of the trough. We accordingly find that it has a depth off the west coast of Iceland of at least 4,800 feet, with an unknown lateral extension. Dr. Carpenter, discussing this opinion, says: “ It is to me physically inconceivable that this surface film of lighter (because warmer) water should collect itself together again—even supposing it still to retain any excess of temperature—and should burrow downwards into the ‘trough,’ dis- placing colder and heavier water, to a depth much greater than that which it possesses at the point of its greatest ‘glory’—its passage through the Florida Narrows. The upholders of this hypothesis have to explain how such a re-collection and dipping-down of the Gulf-stream water is to be accounted for on physical principles.” * I believe that as a rule, experimental imitations on a small scale are of little use in the illustration of natural phenomena; a very simple experiment will, however, show that such a process is possible. If we put a tablespoonful of cochineal into a can of hot water, so as to give it a red tint, and then run it through a piece of india- rubber tube with a considerable impulse along the surface of a quantity of cold water in a bath, we see ? Dr. Carpenter's Address to Geographical Society, op. cit. 398 THE DEPTHS OF THE SEA. (cua. vitr, the red stream widening out and becoming paler over the general surface of the water till it reaches the opposite edge, and very shortly the rapidly heightening colour of a band along the opposite wall indicates an accumulation of the coloured water where its current is arrested. If we now dip the hand into the water of the centre of the bath, a warm bracelet merely encircles the wrist; while at the end of the bath opposite the warm influx, the hot water, though considerably mixed, envelopes the whole hand. The North Atlantic forms a basin closed to the northward. Into the corner of this basin, as into a bath,—with a north-easterly direction given to it by its initial velocity, as if the supply pipe of the bath were turned so as to give the hot water a definite impulse,—this enormous flood is poured, day and night, winter and summer. When the basin is full —and not till then—overcoming its northern impulse, the surplus water turns southwards in a southern eddy, so that there is a certain tendency for the hot water to accumulate in the northern basin, to ‘bank down’? along the north-eastern coasts. It is scarcely necessary to say that for every unit of water which enters the basin of the North Atlantic, and which is not evaporated, an equivalent must return. As cold water can gravitate into the deeper parts of the ocean from all directions, it is only under peculiar circumstances that any move- ment having the character of a current is induced; *Ocean Currents. An Address delivered to the Royal United Service Institution June 15th, 1871. By J. K. Laughton, M.A, Naval Instructor at the Royal Naval College. (From the Journal of the Institution, vol. xv.) CHAP. VIII] THE GULF-STREAM. 399 these circumstances occur, however, in the confined and contracted communication between the North Atlantic and the Arctic Sea. Between Cape Fare- well and North Cape there are only two channels of any considerable depth, the one very narrow along the east coast of Iceland, and the other along the east coast of Greenland. The shallow part of the sea is entirely occupied, at all events during summer, by the warm water of the Gulf- stream, except at one point, where a rapid current of cold water, very restricted and very shallow, sweeps round the south of Spitzbergen and then dips under the Gulf-stream water at the northern entrance of the German Ocean. This cold flow, at first a current, finally a mere indraught, affects greatly the temperature of the German Ocean; but it is entirely lost, for the slight current which is again produced by the great con- traction at the Strait of Dover, has a summer tem- perature of 7°5C. The path of the cold indraught from Spitzbergen may be readily traced on the map by the depressions in the surface isothermal lines, and in dredging by the abundance of gigantic amphi- podous and isopodous crustaceans, and other well- known Arctic animal forms, From its low initial velocity the Arctic return current, or indraught, must doubtless tend slightly in a westerly direction, and the higher specific gravity of the cold water may probably even more power- fully lead it into the deepest channels; or possibly the two causes may combine, and in the course of ages the currents may hollow out deep south- westerly grooves. At all events, the main Arctic 400 THE DEPTHS OF THE SEA. [cuap. vit. return currents are very visible on the chart taking this direction, indicated by marked deflections of the iscthermal lines. The most marked is the Labrador current, which passes down inside the Gulf-stream along the coasts of Carolina and New Jersey, meeting it in the strange abrupt ‘cold wall,’ dipping under it as it issues from the Gulf, coming to the surface again on the other side, and a portion of it actually passing, under the Gulf- stream, as a cold counter-current into the Gulf of Mexico. Fifty or sixty miles out from the west coast of Scotland, I believe the Gulf-stream forms another, though a very mitigated, ‘cold wall.’ In 1868, after our first investigation of the very remarkable cold indraught into the channel between Shetland and Feroe, I stated my belief that the current was entirely banked up in the Féroe Channel by the Gulf-stream passing its gorge. Since that time I have been led to suspect that a part of the Arctic water oozes down the Scottish coast, much mixed, and sufficiently shallow to be affected throughout by solar radiation. About sixty or seventy miles from shore the isother- mal lines have a slight but uniform deflection. Within that line types characteristic of the Scandi- navian fauna are numerous in shallow water, and in the course of many years’ use of the towing net I have never met with any of the Gulf-stream pteropods, or of the lovely Polycystina and Acantho- metrina which absolutely swarm beyond that limit. The difference in mean temperature between the east and west coasts of Scotland, amounting to about 1°C., is also somewhat less than might be CHAP. VIII. ] THE GULF-STREAM. 401 expected if the Gulf-stream came close to the western shore. While the communication between the North Atlantic, and the Arctic Sea—itself a second cul de sac—is thus restricted, limiting the interchange of warm and cold water in the normal direction of the flow of the Gulf-stream, and causing the diversion of a large part of the stream to the southwards, the communication with the Antarctic basin is as open as the day ;—a continuous and wide valley upwards of 2,000 fathoms in depth stretching northwards along the western coasts of Africa and Europe. That the southern water wells up into this valley there could be little doubt from the form of the ground; hut here again we have curious corroborative evidence on the map in the remarkable reversal of the curves of the isotherms. The temperature of the bot- tom water at 1,230 fathoms off Rockall is 3°22 C., exactly the same as that of water at the same depth in the serial sounding, lat. 47°38’ N., long. 12° 08’ W. in the Bay of Biscay, which affords a strong presumption that the water in both cases is derived from the same source; and the bottom water off Rockall is warmer than the bottom water in the Bay of Biscay (2°5 C.), while a cordon of temperature soundings drawn from the north-west of Scotland to a point on the Iceland shallow gives no temperature lower than 6°5 C. This makes it very improbable that the low temperature of the Bay of Biscay is due to any considerable por- tion of the Spitzbergen current passing down the west coast of Scotland; and as the cold current to the east of Iceland passes southwards considerably to the westward, as indicated on the map by the successive DD 402 THE DEPTAS OF THE SEA. [enap, vill. depressions in the surface isotherms, the balance of probability seems to be in favour of the view that the conditions of temperature and the slow movement of this vast mass of moderately cold water, nearly two statute miles in depth, are to be referred to an Antarctic rather than to an Arctic origin. The North Atlantic Ocean seems to consist first of a great sheet of warm water, the general northerly reflux of the equatorial current. Of this the greater part passes through the Strait of Florida, and its north-easterly flow is aided and maintained by the anti-trades, the whole, being generally called the Gulf-stream. This layer is of varying depths, ap- parently from the observations of Captain Chimmo and others, thinning to a hundred fathoms or so in the mid-Atlantic, but attaining a depth of 700 to 800 fathoms off the west coasts of Ireland and Spain. Secondly of a ‘stratum of intermixture’ which ex- tends to about 200 fathoms in the Bay of Biscay, through which the temperature falls rather rapidly ; and thirdly, of an underlying mass of cold water, in the Bay of Biscay 1,500 fathoms deep, derived as an indraught falling in by gravitation from the deepest available source, whether Arctic or Antarctic. It seems at first sight a startling suggestion, that the cold water filling deep ocean valleys in the northern hemisphere may be partly derived from the southern; but this difficulty, I believe, arises from the idea that there is a kind of diaphragm at the equator between the northern and southern ocean basins, one of the many misconceptions which follow in the train of a notion of a convective circulation in the sea similar to that in the atmosphere. There is CHAP. VIII.] . THE GULF-STREAM. 403 undoubtedly a gradual elevation of an intertropical belt of the underlying cold water, which is being raised by the subsiding of still colder water into its bed to supply the place of the water removed by the equatorial current and by excessive evaporation; but such a movement must be widely and irregularly diffused and excessively slow, not in any sense com- parable with the diaphragm produced in the atmo- sphere by the rushing upwards of the north-east and south-east trade-winds in the zone of calms. Perhaps one of the most conclusive proofs of the extreme slowness of the movement of the deep indraught is the nature of the bottom. Over a great part of the floor of the Atlantic a deposit is being formed of microscopic shells. These with their living inha- bitants differ little in specific weight from the water itself, and form a creamy flocculent layer, which must be at once removed wherever there is a perceptible movement. In water of moderate depth, in the course of any of the currents, this deposit is entirely absent, and is replaced by coarser or finer gravel. It is only on the surface of the sea that a line is drawn between the two hemispheres by the equatorial current, whose effect in shedding a vast intertropical drift of water on either side as it breaks against the eastern shores of equatorial land may be seen at a glance on the most elementary physical chart. The Gulf-stream loses an enormous amount of heat in its northern tour. Ata point 200 miles west of Ushant, where observations at the greatest depths were made on board the ‘ Porcupine,’ a section of the water of the Atlantic shows three surfaces at which interchange of temperature is taking place. ° DD2 404 THE DEPTHS OF THE SEA. [ouap. vin. First, the surface of the sea—that is to say, the upper surface of the Gulfstream layer—is losing heat rapidly by radiation, by contact with a layer of air which is in constant motion and being per- petually cooled by convection, and by the con- version of water into vapour.' As this cooling of the Gulf-stream layer takes place principally at the surface, the temperature of the mass is kept pretty uniform by convection. Secondly, the band of con- tact of the lower surface of the Gulf-stream water with the upper surface of the cold indraught. Here the interchange of temperature must be very slow, though that it does take place is shown by the slight depression of the surface isotherms over the principal paths of the indraught. But there is a good deal of intermixture extending through a con- siderable layer. The cold water being beneath, convection in the ordinary sense cannot occur, and interchange of temperature must depend mainly upon conduction and diffusion, causes which in the case of masses of water must be almost secular in their action, and probably to a much greater extent upon mixture produced by local currents and by the tides. The third surface is that of contact be- tween the cold indraught and the bottom of the sea. The temperature of the crust of the earth has been variously calculated at from 4° to 11°C., but it must be completely cooled down by anything like a movement and constant renewal of cold water. * On Deep-sea Climates. The Substance of a Lecture delivered to the Natural Science Class in Queen’s College, Belfast, at the close of the Summer Session 1870, by Professor Wyville Thomson. (ature, July 28th, 1870.) CMAP. VI1I.] THE GULF-STREAM. 405 All we can say, therefore, is that contact with the bottom can never be a source of depression of tem- perature. Asa general result the Gulf-stream water is nearly uniform in temperature throughout the greater part of its depth; there is a marked zone of intermixture at the junction between the warm water and the cold, and the water of the cold indraught is regularly stratified by gravitation ; so that in deep water the contour lines of the sea-bottom are, speaking generally, lines of equal temperature. Keeping in view the enormous in- fluence which ocean currents exercise in the dis- tribution of climates at the present time, I think it is scarcely going too far to suppose that such currents—movements communicated to the water by constant winds—existed at all geological periods as the great means, I had almost said the sole means, of producing a general oceanic circulation, and thus distributing heat in the ocean. They must have existed, in fact, wherever equatorial land inter- rupted the path of the drift of the trade-winds. Wherever a warm current was deflected to north or south from the equatorial belt a polar indraught crept in beneath to supply its place; and the ocean consequently consisted, as in the Atlantic and doubtless in the Pacific at the present day, of an upper warm stratum, and a lower layer of cold water becoming gradually colder with increasing depth. I fear, then, that in opposition to the views of my distinguished colleague, I must repeat that I have seen as yet no reason to modify the opinion which I have consistently held from the first, that 406 THE DEPTHS OF THE SEA. (CHAP. VIII. the remarkable conditions of climate on the coasts of Northern Europe are due in a broad sense solely to the Gulf-stream. That is to say, that although movements, some of them possibly of considerable importance, must be produced by differences of spe- cific gravity, yet the influence of the great current which we call the Gulf-stream, the reflux of the ereat equatorial current, is so paramount as to reduce all other causes to utter insignificance. THE GIANT AND THE HAG CHAPTER IX. THE DEEP-SEA FAUNA. The Protozoa of the Deep-sea.— Bathybius.—‘ Coccoliths,’ and ‘ Cocco- spheres.’—The Foraminifera of the Warm and Cold Areas.—Deep- sea Sponges. — The Hexactinellide. — Rossella.— Hyalonema.— Deep-sea Corals.—The Stalked Crinoids,—Pentacrinus.—Rhizo- crinus. — Bathycrinus,— The Star-fishes of the Deep-sea.—The general Distribution and Relations of Deep-sea Urchins.—The Crustacea, the Mollusca, and the Fishes of the ‘ Porcupine’ Expe- ditions. TuE time has not yet arrived for giving anything like a detailed account of the deep-sea fauna; even if it were possible to do so in a popular sketch of the general results of a wide investigation. I must therefore confine myself at present to a brief outline of the distribution of the forms of animal life which were met with in the belt partially examined during the ‘ Porcupine’ dredgings, a belt which carries the British zoological area about a hundred miles further out to seaward along the northern and western coasts of the British Isles, and into depths extending from 200 fathoms, the previous limit of accurate know- ledge, to 800 and 1,000 fathoms, and in one or two instances to the extreme depth of upwards of 2,000 fathoms. A408 THE DEPTHS OF THE SEA. (CHAP. 1X, The remarkable general result that even to these great depths the fauna is varied and rich in all the marine invertebrate groups, has inundated us with new material which in several of the larger depart- ments it will take years of the labour of specialists to work up. While referring very briefly to those orders which it has been found impossible as yet to overtake, I will enter a little more fully into the history of certain restricted groups which more par- ticularly illustrate the conditions of the abyssal region, and the relations of its special fauna to the faunze of other zoological provinces, or to those of earlier times. And very prominent among these special groups we find the first and simplest of the in- vertebrate sub-kingdoms, the Protozoa, represented by three of its classes,—the monera, the rhizopoda, and the sponges. The monera have been lately defined as a distinct class by Professor Ernst Haeckel,’ for a vast assem- blage of almost formless beings, apparently abso- lutely devoid of internal structure, and consisting simply of living and moving expansions of jelly-like protoplasm ; and although the special character on which Haeckel separates them from the remainder of the protozoa,—that they are propagated by no form of sexual reproduction, but simply by spontaneous division,—-may probably prove deceptive as our know- ledge increases, still their number, their general resemblance to one another, presenting obviously different and recognizable kinds although with very indefinable characters, and the important part which * Biologische Studien. Von Dr. Ernst Haeckel, Professor an der Universitat Jena. Leipzig, 1870. CHAP. IX. ] THE DEEP-SEA FAUNA. “409 they play in the economy of nature, would seem to entitle them to a systematic position of more than ordinal value. The German naturalists of the new school, in their enthusiastic adoption of the Dar- winian theory of evolution, naturally welcome in these ‘moners’ the essential attribute of the ‘ Ur- schleim,’ an infinite capacity for improvement in every conceivable direction ; and to more prosaic physiologists they are of the deepest interest, as presenting the essential phenomena of life, nutri- tion and irritability, existing apparently simply as the properties of a homogeneous chemical compound, and independent of organization. The monera pass into the rhizopoda, which give a slight indication of advance, in the definite form of the graceful calcareous shell-like structures which most of them secrete, and the two groups may be taken together. The dredging at 2,485 fathoms at the mouth of the Bay of Biscay gave a very fair idea of the con- dition of the bottom of the sea over an enormous area, as we know from many observations which have now been made, with the various sounding instruments contrived to bring up a sample of the bottom. On that occasion the dredge brought up about 14 ewt. of calcareous mud. There could be little doubt, from the appearance of the contents of the dredge, that the heavy dredge-frame had gone down with a plunge, and partly buried itself in the soft, yielding bottom. The throat of the dredge thus became partly choked, and the free entrance of the organisms on the sea-floor had been thus prevented. he matter contained in the dredge con- 410 THE DEPTHS OF THE SEA. (CHAP. IX, sisted mainly of a compact ‘mortar,’ of a bluish colour, passing into a thin—evidently superficial— layer, much softer and more creamy in consistence, and of a yellowish colour. Under the microscope the surface-layer was found to consist chiefly of entire shells of Globigerina bulloides (Fig. 2, p. 22), large and small, and fragments of such shells mixed with a quantity of amorphous calcareous matter in fine particles, a little fine sand, and many spicules, portions of spicules, and shells of Radiolaria, a few spicules of sponges, and a few frustules of diatoms. Below the surface-layer the sediment becomes gradually more compact, and a slight grey colour, due probably to the decomposing organic matter, becomes more pronounced, while perfect shells of globigerina almost entirely disappear, fragments be- come smaller, and calcareous mud, structureless and in a fine state of division, is in greatly preponderating proportion. One can have no doubt, on examining this sediment, that it is formed in the main by the accumulation and disintegration of the shells of globigerina—the shells fresh, whole, and living in the surface-layer of the deposit, and in the lower layers dead, and gradually crumbling down by the decomposition of their organic cement, and by the pressure of the layers above—an animal formation in fact being formed very much in the same way as in the accumulation of vegetable matter in a peat bog, by life and growth above, and death, retarded de- composition, and compression beneath. In this dredging, as in most others in the bed of the Atlantic, there was evidence of a considerable quantity of soft gelatinous organic matter, enough cap. 1X.] THE DEEP-SEA FAUNA. 411 to give a slight viscosity to the mud of the surface layer. If the mud be shaken with weak spirit of wine, fine flakes separate like coagulated mucus ; and if a little of the mud in which this viscid con- dition is most marked be placed in a drop of sea- water under the microscope, we can usually see, after a time, an irregular network of matter resem- bling white of egg, distinguishable by its maintaining its outline and not mixing with the water. This network may be seen gradually altering in form, and entangled granules and foreign bodies change their relative positions. The gelatinous matter is therefore capable of a certain amount of movement, and there can be no doubt that it manifests the phenomena of a very simple form of life. To this organism, if a being can be so called which, shows no trace of differentiation of organs, consist- ing apparently of an amorphous sheet of a protein compound, irritable to a low degree and capable of assimilating food, Professor Huxley has given the name of Bathybius haeckelii (Fig. 63). If this have a claim to be recognized as a distinct living entity, ex- hibiting its mature and final form, it must be referred to the simplest division of the shell-less rhizopoda, or if we adopt the class proposed by Professor Haeckel, to the monera. The circumstance which gives its special interest to Bathybius is its enormous extent : whether it be continuous in one vast sheet, or broken up into circumscribed individual particles, it appears to extend over a large part of the bed of the ocean ; and as no living thing, however slowly it may live, is ever perfectly at rest, but is continually acting and reacting with its surroundings, the bottom of the 412 THE DEPTHS OF THE SEA. (CHAP. Ix, sea becomes like the surface of the sea and of the land,—a theatre of change, performing its part in maintaining the ‘ balance of organic nature.’ Fig. 63.—“‘Bine gréssere Cytode von Bathybius mit eingebetteten Coccolithen. Das Proto- plasma, welches viele Discolithen und Cyatholithen enthilt, bildet ein Netzwerk mit breiten Stringen.’ (x. 700,)1 1 Biologische Studien. Von Dr. Ernst Haeckel, Professor an der Universitat Jena. Leipzig, 1870. CHAP. IX.] THE DEEP-SEA FAUNA. 4138 Entangled and borne along in the viscid streams of Bathybius, we so constantly find a multitude of minute calcareous bodies of a peculiar shape, that the two were for long supposed to have some mutual relation to one another. These small bodies, which have been carefully . studied by Huxley,’ Sorby,? Haeckel,®. Carter, Giimbel,® and others, are in shape somewhat like oval shirt-studs: There is first a little oval disk about 0-01 mm. in length, with an oblong rudely facetted elevation in the centre, and round that, in fresh specimens, what seems to be a kind of frill of organic matter, then a short neck, and lastly a second smaller flat disk, like the disk at the back of a stud. To these bodies, which are met with in all stages of development, Professor Huxley has given the name of ‘ coccoliths.’ Some- times they are found aggregated on the surface of small transparent membranous balls, and _ these which seemed at first to have something to do with the production of the ‘ coccoliths’ Dr. Wallich has called ‘coccospheres’ (Fig. 64). Professor Ernst Haeckel has lately described a very elegant organ- ism belonging to the radiolaria and apparently allied to Thalassicolla,— Myxobrachia rhopalum,—and at the ends of some curious diverging appendages of this creature he has detected accumulations of bodies closely resembling, if not identical with, the coccoliths and coccospheres of the sea-bottom. These ? Quarterly Journal of Microscopical Science, 1868, p. 203. ? Proceedings of the Sheffield Literary and Philosophical Society, October 1860. = Op. cit. * Ann. and Mag. Nat. Hist. 1871, p. 184. ® Jahrbuch Miinch. 1870, p. 753. 414 THE DEPTHS OF THE SEA. [cHAP. Ix, bodies seem to have been taken in to the Myzo- brachia as food, the hard parts accumulating in cavities in the animal’s body after all the available nourishment had been absorbed. It is undoubted that a large number of the organisms whose skele- tons are mixed with the ooze of the bottom of the sea live on the surface, the delicate silicious or cal- careous shields or spines falling gradually through Fic. 64.—‘Coccosphere.’ (x. 1000.) the water and finally reaching the bottom, what- ever be the depth. I think that now the balance of opinion is in favour of the view that the coccoliths are joints of a minute unicellular alga living on the sea-surface and sinking down and mixing with the sarcode of Bathybius, very probably taken into it with a purpose, for the sake of the vegetable matter they may contain, and which may afford food for the animal jelly. What the coccospheres are, and CHAP. IX.] THE DEEP-SEA FAUNA, 415 what relation, if any, they have to the coccoliths, we do not know. | Living upon and among this Bathybius, we find a multitude of other protozoa,—foraminifera and other rhizopods, radiolarians, and sponges; and we as yet know very little of the life-history of these groups. There can be no doubt that when their development has been fully traced many of them will be found to be di- or poly-morphic, and that when we are acquainted with their mode of multi- plication we shall meet with many cases of pleo- morphism and wide differences between the organs and products involved in propagation and in repro- duction. I feel by no means satisfied that Bathybius is the permanent form of any distinct living being. It has seemed. to me that different samples have been different in appearance and consistence; and although there is nothing at all improbable in the abundance of a very simple shell-less ‘moner’ at the bottom of the sea, I think it not impossible that a great deal of the ‘bathybius,’ that is to say the diffused formless protoplasm which we find at great depths, may be a kind of mycelium—a formless condition connected either with the growth and multiplication or with the decay—of many different things. Many foraminifera of different groups inhabit the deep water, lying upon or mixed in the upper layer of the globigerina ooze, or fixed to some foreign body, such as a sponge, coral, or stone; and all of these are remarkable for their large size. In the ‘warm area,’ and wherever the bottom is covered with ooze, calcareous forms predominate, and large sandy cristellarians, with their sand-grains bound together 416 THE DEPTHS OF THE SEA. (cHAP. 1x, by calcareous cement, so that the sand-grains show out, dark and conspicuous, scattered on the surface of the white shell. Miliolines are abundant, and the specimens of Cornuspira and Biloculina are greatly larger than anything which has been hitherto met with in temperate regions, recalling the tropical forms which abound among the Pacific Islands. Jn the cold area, and in the paths of cold currents, foraminifera with sandy tests are more numerous; some of those of the genera H ae Rhetic | f London Upper Lower and Per- Carbo- ; Atlantic.) Crag. | * clay, Chalk. | Jurassic. | Jurassic. | Upper mian. | niferous. | - Trias. —|—}-—}—- — » ib 53 | 28 | 19 4 i ro) a : i The morphology of the foraminifera has been studied with great care, and the differences between closely allied so-called species are so slight that it is possible that in many cases they should only be regarded as varieties; but this careful criticism and appreciation of minute differences renders it all the more likely that the determinations are correct, and that animal forms which are substantially identical have persisted in the depths of the sea during a con- siderable lapse of geological time. In the late deep-sea dredgings by M. de Paunteltes off the American coast, and by H.M. ships ‘ Light- ning’ and‘ Porcupine,’ and Mr. Marshall Hall’s yacht ‘Norna” off the. west coast of Europe, no animal forms have been discovered belonging to any of the higher groups, so far as we are as yet aware, speci- fically identical with chalk fossils ; and I do not think that we have any right to expect that such will be found. To a depth of 5,000 feet or so a large portion of the North Atlantic is at present heated very con- siderably above its normal temperature, while the Arctic and Antarctic indraught depresses the bottom 480 THE DEPTHS OF THE SEA. [cHar. x, temperature in deep water to a like extreme degree. These abnormal temperatures are dependent upon the present distribution of sea and land; and I have already shown that we have evidence of many oscillations, in modern times geologically speaking, which must have produced totally different condi- tions of temperature over the same area. Accepting, as I believe we are now bound to do in some form, the gradual alteration of species through natural causes, we must be prepared to expect a total absence of forms identical with those found in the old chalk, belonging to groups in which there is sufficient structural differentiation to require or to admit of marked variation under altering circumstances. The utmost which can be expected is the persistence of some of the old generic types, and such a resemblance between the two faune as to justify the opinion that, making due allowance for emigration, immigration, and extermination, the later fauna bears to the earlier the relation of descent with extreme modi- fication. : I have already mentioned that one of the most remarkable differences between the recent Atlantic chalk-mud and the ancient white chalk is the total absence in the latter of free silica. It would seem, from the analysis of chalk, that silicious organisms were entirely wanting in the ancient cretaceous seas. In the chalk mud, on the other hand, silica is found in abundance, in most specimens to the amount of from 30 to 40 per cent. A considerable portion of this is inorganic silica—sand; and its presence is doubtless due to the cireumstance that our dredgings have hitherto been carried on in the neighbourhood cHap. x.] CONTINUITY OF HE CHALK. 481 of land and in the path of slight currents, whilst the extreme purity of the white chalk of Sussex would seem to indicate that it had been laid down in deep still water far from land. . . 50°12 Alumina ? (‘soluble in acids BN age yee oe . . 133 Sesquioxide of iron (‘soluble in acids’) . , . 2°17 Silica (in a soluble condition). . . . . . 504 Fine insoluble a sand (rock deri) or 26°77 Water . . . . « 290 Organic matter . . . : age <1 Chloride of sodium and other ‘gohuble salts . . 7:48 100°00 If we compare the chemical composition as above with that of ordinary chalk, which consists all but entirely of carbonate of lime, and seldom contains more than from 2 to 4 per cent. of foreign matter (clay, silica, &c.), it will be seen that it differs chiefly in containing so very large an amount of rock-matter in a fine state of division. If we subtract the water, organic matter, and marine salts, which would probably in greatest part be removed before such mud could in process of ages be converted into solid rock, even then the amount of carbonate of lime or pure chalk would not be more than at highest some 60 per cent. of the mass. As such deposits must naturally be expected to vary greatly in mechanical character and chemical composition, it would be 1 With phosphoric acid. CHAP. X.] CONTINUITY OF THE CHALK. 515 premature to generalize as to the actual nature of the deposits now in course of formation in the depths of the Atlantic, before a caretul examination had been made of a series of such speci- mens from different localities. The soluble silica is principally from silicious organisms. As regards the probable origin of the pebbles and gravel found in the various dredgings, it will be at once seen, from the description, that they consist principally of fragments of vol- canic rocks and crystalline schists. The former of these have in all probability come from Iceland or Jan Mayen; whilst the latter, associated as they are with small fragments of grey and somewhat altered calcareous rock, would appear to have pro- ceeded from the north-west coast of Ireland, where the rocks are quite identical in mineral character. The north of Scotland and its islands also contain similar rocks; but, without being at all positive on this head, I am rather inclined to the opinion that they have been derived from Ireland, and not necessarily connected with any glacial phenomena, believing that their presence may be accounted for by the ordinary action of marine currents. PEBBLES FROM 1,215 FatTHoms (STATION 28). The stones were all subangular, the edges being all more or less worn or altogether rounded off. The specimens were thirty- eight in number, and upon examination were found to consist of— 5 Horblende schist; the largest of these (which also was the largest in size of the entire series) weighed 421 grains ($ of an ounce), was extremely compact, and was composed of black hornblende, dirty-coloured quartz, and some garnet. 2 Mica schist; quartz with mica, the largest weighing 20 grains. 5 Grey pretty compact limestone, the largest being 7 grains in weight. 2 Fragments (showing the cleavage faces rounded off on edges) of orthoclase (potash felspar), evidently derived LL2 516 THE DEPTHS OF THE SEd. [CHAP. x. from granite; the largest of the two fragments weighed 15 grains. 5 Quartz, milky in colour or colourless; the largest of these weighed 902 grains, and showed evidence of having been derived from the quartz-veins so common in clay-slate. 19 Fragments of true volcanic lava, most of which were very — light and scoriaceous (vesicular), although some small 38 ones were compact and crystalline; and in these the minerals augite, olivine, and glassy felspar (Sanadine) could be distinctly recognized. Among these were frag- ments of trachytic, trachydoleritic, and pyroxenic (basaltic) lavas, quite similar to those of Iceland or Jan Mayen of the present period, from which they had probably been derived. GRAVEL FROM 1,443 Farnoms (Station 20). This sample of gravel consisted of 718 subangular fragments, in general not above from 4 to 4 grain in weight, with occasion- ally some of a little greater size; but the most considerable of all (a fragment of mica schist) only weighed 3 grains. They consisted of :— 3 Fragments of orthoclase felspar. 4 Bituminous or carbonaceous shale (? if not accidental). 5 Fragments of shell (undistinguishable species). 4 Granite, containing quartz, orthoclase, and muscovite. 15 Grey compact limestone. 69 Quartzose mica schist. 317 Hornblende schist; sometimes containing garnets. 273 Quartzite fragments, with a very few fragments of clear quartz. The majority of the pieces being of a dirty colour, often cemented together, were evidently the débris of quartzite rocks or beds of indurated sandstone, and not from granite. 28 Black compact rock, containing augite, most probably a -— volcanic basalt. 718 CHAP. X.] CONTINUITY OF THE CHALK. 517 From 1,263 Farooms (Station 22). A single rounded pebble, weighing 18 grains, chiefly quartz, with a little of a black mineral hornblende or tourmaline, prob- ably from a metamorphic schist. GRAVEL FROM 1,366 Fatuoms (Station 19a). Consisted of 51 small subangular pieces of rock, all less than 4 grain in weight, excepting only one fragment (angular) of quartz, which weighed 2 grains; they consisted of — 19 Fragments of quartz, all of which appeared to have pro- ceeded from the disintegration of crystalline schists, and not from granite. 9 Hornblende schist. 8 Mica schist. 7 Loose, dirty-white tufaceous limestone. 3 Small fragments of augite or tourmaline (? which). 1 Fragment of quartz, with tourmaline. 4 Fragments of indistinct and uncertain character. 51 GRAVEL FRom 1,476 Faruoms (Starion 21). Six small subangular fragments, the largest of which did not exceed two grains in weight; they were respectively — 1 Yellow quartz. 1 Quartzose chlorite schist. 3 Mica schist. 1 Small fragment, apparently of volcanic lava. 6 The specimen from Rockall is not a fragment of any normal rock, but is only a brecciaform aggregate, principally consisting of quartz, felspar, and crystals of green hornblende, held to- gether by a silicious cement. It has evidently been broken from the projecting edge of a fault or vein fissure ; and although it cannot settle the matter definitely as to what rocks this islet may really be composed of, it would indicate that it most 518 THE DEPTHS OF THE SEA. [cHaP. x, probably is a mass of hornblendic gneiss or schist, and certainly not of true volcanic origin. I may mention that it does not at all resemble any of the fragments found in the deep-sea dredgings which I have as yet examined. APPENDIX D. Note on the Carbonic Acid contained in Sea-water, By JOHN Youna Bucuanay, M.A., Chemist to the ‘Challenger’ Expedition. At a meeting! of the Chemical Society last summer, Dr. Himly mentioned that Dr. Jacobsen, of Kiel, had found that carbonic acid is only very imperfectly separated from sea-water by boiling ‘tm vacuo. This was confirmed by Dr. Jacobsen him- self in a letter to Nature of August 8, 1872. Almost at the very same time the German North Sea Expedition arrived in Leith, when I had the privilege of hearing the confirmation of it from his own mouth, as well as his conjecture that it was probably owing to the presence of salts with water of hal- hydration, such as sulphate of magnesia, that the carbonic acid was retained with such vigour. Having assured myself by experiment that, as a matter of fact, carbonic acid is retained by sea-water with considerable energy, the last traces of it having scarcely disappeared before the contents of the retort were reduced to dryness, I set on foot a series of analytical experiments, so as to determine which of the salts it was, whose presence was the cause of the anomaly in question. The result of these experiments was shortly this: Distilled water, solution of chloride of sodium and solution of chloride of magnesium, each saturated with carbonic acid, behaved on distillation alike, giving off the whole of their car- bonie acid in the first eighth of the distillate. Solutions, however, of sulphate of magnesia and of sulphate of lime behaved like 1 Chemical Society Journal, 1872, p. £55. car. x.] CONTINUITY OF THE CHALK. 519 the others at first, giving off the surplus carbonic acid dissolved in the first eighth of the distillate. The amount of carbonic acid coming off then fell very low, gradually increasing, however, until a half had been distilled over, when the amount coming off again reached a maximum, the quantity then diminishing | but rarely entirely disappearing as the contents of the retort approached dryness. It is clear, then, that in the sulphates of magnesia and lime we have an agent capable of retaining car- bonic acid in the way in which we see it in sea-water; whether there may be other agents present, capable of doing the same work, will be brought to light when the subject has been more fully investigated. An independent set of experiments were made on the variation with pressure of the coefficient of ab- sorption for carbonic acid of a solution containing 1:23 per cent. of crystallized sulphate of magnesia, kept at a constant tem- perature of 11°C. The result was, that at 610 mm. pressure the sulphate of magnesia solution dissolved sensibly the same quan- tity of carbonic acid as the same volume of water would have done; in other words, their coefficients of absorption were iden- tical. Below 610 mm. that of the saline solution was the greater; above 610 mm. the reverse was the case. The curve, however, is not a straight line, and it appears to cut that of water again at a pressure of about 800 mm. The facts above related naturally suggest to the chemist the question, what is the body formed when sulphate of magnesia and carbonic acid meet each other in solution ? It is clear that, besides the carbonic acid dissolved, there is some retained by a stronger bond, and which is only liberated when the concentration has proceeded a certain distance. Is the decomposition caused by the loss of water, or by the rise of boiling-point? The difference between the boiling-points of the solution, when it has just ceased to give off the merely dissolved carbonic acid, and when the retained gas is being given off in greatest quantity, does not exceed 1° C.; and it is difficult to believe that the compound should remain practically intact at 101° and decompose rapidly at 102°. Again, if the compound is decomposed by the water alone, we should expect, that the 520 TIE DEPTHS OF THE SEA. [omar. x: more dilute the solution, the easier would be the decomposition. Adopting Erlenmeyer’s view of the position of the halhydration water in sulphate of magnesia (HO — Mg — 0 — SO, — OH), we might suppose the carbonic acid simply to replace the molecule of water, thus—Mg a - ne yo ; but it would be contrary to all analogy for such a body to be more stable in dilute than in moderately concentrated solutions of the same temperature. If, on the other hand, we suppose the CO, to interpose itself between the Mg and the basic HO, we have a body of this form : HO — CO — 0 — Mg — 0 — SO, — OH. Itis conceivable that such a body would in the process of concentration become dehy- XS drated, when the anhydrous salt MP — S02 /O would be formed, which would then split up into CO, and MgSO,. Assuming now that the body formed has this constitution, it is evident that, .for a given mixture of sulphate of magnesia, water and carbonic acid, the amount of the above body formed will be a function of the temperature, the pressure and the duration of their action upon one another. Now, at great depths in the sea, where atmospheric influences are insensible, these conditions are most completely fulfilled. The temperature is low, the pressure high, and the time practically unlimited. Sea-water contains on an average about two grammes of crystallized sulphate of magnesia in the litre; and if the reaction were complete, the two grammes of sulphate of magnesia, or one litre of sea-water, would absorb 1814 cubic centimetres of carbonic acid. Supposing only one-fifth part of the sulphate of magnesia to be thus saturated with carbonic acid, we have provision in one litre of sea- water fer the removal of over 36 cubic centimetres of car- bonic acid. We have thus in the sulphates (for the lime-salt appears to act even more energetically) an agent which in the ocean depths performs one of the two important functions of plants in shallow waters and in the air, namely, the removal of the carbonic acid eliminated by the animals; the task of replenishing the oxygen supply is accomplished by the system of ocean circulation. Moreover, it would be difficult to conceive CHAP. x.] CONTINUITY OF THE CHALK. 521 circumstances more favourable to the formation of this body than those which exist at the bottom of the ocean, The temperature is generally little over that of melting ice; the pressure often exceeds several hundred atmospheres ; whilst the carbonic acid, being produced gradually, and coming in statu nascendis in con- tact with the saline solution, is in the condition most favourable for easily entering into chemical combination. The amount of this salt formed depending on the pressure, it is evident that, on bringing up a sample of water from a great ‘depth, a part of the carbonic acid, which was bound before, will become free under the atmospheric pressure; and, moreover, as the amount decomposed varies with the time, it is evident that the amount of free carbonic acid, obtained by boiling in vacuo, will vary with the depths from which the sample was obtained, with the time it stands before boiling, with the temperature to which it is exposed during boiling, and with the duration of that operation. Hence it is easy to see how, assuming the body above mentioned to have been formed, Dr. Jacobsen found that the quantity of carbonic acid obtained by boiling im vacuo was no measure of the amount actually present, and that even portioris of the same sample gave discordant results. It will be seen from the above remarks that solutions of car- bonic acid in sea-water and in blood resemble each other in almost every particular; only in the latter the retaining body is phosphate of soda, whilst in the former it is sulphate of mag- nesia, both of which contain constitutional water. The physical conditions, under which carbonic acid is eliminated from the blood and from sea-water, are also very similar. In the investigation of the behaviour of carbonic acid and of other gases to saline solutions, there is a practically unlimited field for useful research. The determination of the absorption coefficients of sulphate of magnesia solution for carbonic acid alone, under varying conditions of temperature, pressure, con- centration, and duration of action, would afford interesting and profitable occupation for more than one chemist. INDEX. A. slcunthometrina, 98. Aga nasuta, 127. Aigean Sea, Mollusca and Radiata of, 5. Agassiz, Alexander, Evhinoderm Fauna on the two sides of the ‘Isthmus of pean, 13; on Kehinocyamus, 117, Allman, Professor, F.R.S., list of animal forms found at great depths, 27. Allopora oculina, 169, 170, 482. Amathia carpenteri, 175. Amphidetus cordatus, 459. Amphihelia profunda—A. oculata—A. Seb atlantica—A. ornata, Amphiura abyssicola, 123. Antedon celticus, 76; A. escrichtii—A. sarstz, 124, Aphrocallistes bocager, 95. Archaster bifrons, 122; A. vexillifer, 150 ; A. andromeda, 150; A. parelii, 456 ; A, tenwispinus, 456. Arcturus baffint, 127, 128. Askonema setubalense, 429, Asterophyton linkit, 19. Astrorhiza limicola, 75. Atavism, 9. Atretia gnomon, 90. RB. Bache, Professor A. D., Superintendent ue Coast Survey, on the Gulf-stream, 6. Bathybius haeckelid, 412. Bathycrinus gracilis, 450, 453, Bathyptilum carpenter i, 77. Berryman, Lieutenant, U.S.N., deep-sea soundings in the U.S. brig ‘ Dolphin,’ 227-229. Bocage, Professor Barboza du, Director of the Nat. Hist. Museum, Lisbon, 275; on Hyalonema, 425. Bowerbank, Dr., F.R.8., on Hyalonema, 425, ‘Carpenter, Dr. Brandt, Dr., on Hyalonema, 423. Brisinga coronata, 67, 118; B. endeca- enemos, 66, 99, 118; description of, by Absjérnsen, P. Chr., 68. Brissopsis lyrifera, 118, 457, 459. Brooke, J. M., U.S.N., sounding appa- ratus, 21, 211, 213. Browning, Lieutenant, 83. Buccinopsis striata, 464. Buchanan, John Young, M.A., on the Carbonic Acid contained in Sea-water, 518, 521. Buff, Professor Henry, on ocean cur- rents, 368; on the Gulf-stream, 389. Cc. Calver, Captain, skill in conducting dredging operations, 83; serial sound- ings, 309. Calverva hystrix, 156, 459; C. fenestrata, 159, 182, 459.- Caprella spinosissima, 126. William B., F.R.S., 3; Preliminary Report of the Dredging Operations in the ‘Lightning,’ 133 ; Temperature Observations in the Me- diterranean, 326; Theory of Ocean Currents, 368, 369; Observations on the eurrents in the Strait of Gibraltar, 373; on the Gulf-stream, 390. Carpenter, W. Lant, B.A., B.Sc., 85; Analysis of Sea-water, 498, 502-511. Caryophylita borealis, 27, 481. Ceratocyathus ornatus, 431. Cerithium granosum, 463. Chalk, 409; analysis of, 469. Chimmo, W., Commander R.N., 230; temperatures of the Atlantic, 359. Choanites, 494, Chondrocladia virgata, 187. Cidaris papillata, 76; C. hystrix, 116, 98, 459 ; C. affinis, 193, 457, 459. Cladorhiza abyssicola, 112, Coccoliths, 413. Coccospheres, 414. Colosphera tubifex, 485. 524 Coralline Zone, 16. Crinoidea, 434. oo James, ou ocean currents, 376, 1. D. Dacrydium vitrewm, 465. Darwin, Charles, M.A., F.R.8., ‘ Origin of Species,’ 8. ai on deep-sea temperatures, 3 Davis, Captain, R.N., testing thermo- meters, 290, 295. Dayman. Joseph, Commander RN., 23, 229, 302; temperatures of the Atlantic, 359. Deep-sea Sounding, 205; cup-lead, 210 ; Brooke’s deep-sea sounding apparatus, 211, 218 ; the ‘ Bulldog’ sounding- machine, 215; the ‘ Fitzgerald’ sound- ing machine. 217 ; the ‘Hydra’ sound- ing-machine, 218 ; donkey-engine, 221 ; derricks, 221; the ‘accumulator,’ 222 ; observed rate of descent of the sounding instrument, 223; Massey’s sounding-machine, 225. Deep-sea Temperature, doctrine of, 35 ; distribution of heat in the sea, 36; cold wall, 37; minimum temperature of the sea, 38; proximity of warm and cold areas, 131; great uniformity of temperature at all depths in the Mediterranean, 191, 285 ; serial soundings for temperature, 3019-325, Depth of the Sea, 1; first successful dredgings at great depths, 3; animal formsfound at depths of from 70 to1,200 fathoms, 27 ; animal life abundant at the bottom of the sea, 31; average depth of the sea, 31 ; absolute stillness at great depths, 37; penetration of light, 45; abundance of the genera Astropecten and Archaster, 121. Despretz, M., researches on the maxi- mum density of saline solutions, 35 ; temperature of greatest density of sea- water, 307. Dorynchus thomsont, 174. Dredging Apparatus: Miiller’s dredge, 289 ; Ball’s dredge, 240 ; deep-sea dredges, 246; derrick, 247; aceumu- lator, 247; Aunt Sallies, 249 ; dredge- rope, 249 ; dredging in shallow water, 244, 245; dredging in deep water, 253 ; hempen tangles, 256, 257 ; empty- ing the dredge, 259; dredging-sieves, 260. Dredging Committee, members of, 265 ; Belfast Dredging Committee, 266. Dredging Operations, on the coast of Ire- land, 266; of England, 266 ; of Shet- land and the Hebrides, 266; of Por- tugal and the Mediterranean, 267; of the North-east Atlantic, 267; of Nor- way, Sweden, and Denmark, 268; of INDEX. the Adriatic, 268; of Algeria, 268 ; Spitzbergen, 269; Malta, 270; Finland and Loffoten Islands, 270; United States, 277. Dredging Paper, 281. Duncan, Professor P. Martin, F.R.S., on deep-sea corals, 431. E. Echinocucumis typica, 125, 175; Echino- Game angulatus, 117, 459; Echino- thuride, wide distribution of, 171; Lichinus elegans, 76, 459; £. escu- lentus, 458 ; E. femingii, 116, 458; L. melo, 459; H. microstoma, 171, 459; E. norvegicus, 76, 116, 459; EH. rari- spina, 459 ; EH. rarituberculatus, 116. Ethusa granulata, 176. Huplectella, 73. Eusirus cuspidatus, 125, 126. Evolution, doctrine of, 9. F Findlay, A. G., on the Gulf-stream, 390, Fishes, new species of, 180. Flabelium distinctum, 432. Florida, fauna of the Strait of, 171. Foraminifera, 115, 166, 415, 478. Forbes, David, F.R.8., analysis of the white chalk of Shoreham, 469; of the Folkestone grey chalk, 469 ; on speci- mens of Atlantic mud, 514-518. Forbes, Edward, F.R.S., 4; on the dis- tribution of marine forms, 6; on the immutability of species, 6; specific centres of distribution, 7; the law of eee nee 8, 13 ; zones of depth, 15; representative forms, 17 ; inverted analogy between the distribution of the fauna and flora of the land and of the sea, 44; on dredging, 266. Fossil Echinide, 162. Frankland, Dr., F.R.S., analysis of sea- water, 511-513. Fusus sarst, 464. G. Geryon tridens, 88. Globigerina bulloides, 22, 416. pelea rhombotdes, 87. oodsir, Henry, deep dredging in Davis’ Strait, 21. ue e ai Gray, Dr. John Edward, F.R.S., on Hyalonema, 422. Gulfstream, 286, 356; description of, 3879; progress and extension of, through the North Atlantic, 385. H Uacckel, Professor Ernst, 9; biological studies, 408. Halichondrida, 74. INDEX. Hall, Marshall, F.G.S., cruise of the *Norna,’ 279 Herschel, Sir John F. W., the doctrine of a constant temperature of 4° C. at great depths, 35; letter to Dr. Car- penter, 378; description of the Gulf- stream, 381. Hexactinellide, 70, 416. Holothuria ecalcarea, 125. Holtenia carpentert, 71; wide distribu- tion of, 75, 101, 167, 417, 427. Humboldt, Baron von, on deep-sea tem- peratures, 360. Hunter, John, M.A., F.C.8., 85; analysis of sea-water, 497. Huxley, Professor T. H., Sec R.S., on life at great depths, 23 ; on the chalk-mud of the Atlantic, 496. Hyalonema, 73, 101, 167, 276, 417, 422, 498; H. lusitanicum, 420, 421; H. sieboldi, 422. Hymenaster pellucidus, 120. I. Inskip, Staff-Commander, 83. Isthmus of Panama, Echinoderm Fauna on the two sides of, 13. J Jeffreys, J. Gwyn, F.R.S., distribution of marine mollusca, 40; first cruise of the ‘Porcupine,’ 84; dredging off the south coast of Ireland, 121; fourth cruise of the ‘Porcupine,’ 178, 267, 278, 418, 428; temperature observa- tions, 325, Jenkin, Professor Fleeming, C.E., F.B.S., eable between Sardinia and Bona, 26; first absolute proof of the existence of highly-organized animals at depths of upwards of 1,000 fathoms, 30. K. Kent, W. Saville, F.L.S., the ‘Norna’ expedition, 75, 279 ; on Askonema setu- balense, 429, Kophobelemmon miillert, 75. Korethraster hispidus, 119. L. Laminarian Zone, 15. Latirus albus, 464. Laughton, J. K., M.A., on ocean cur- rents, 398. Lee, Lieutenant, U.S.N., deep-sea sound- ings, 229, 392. ‘Lightning,’ cruise of the, 57 ; the Faroe Banks, 60; the F#roe Islands, 61 ; Thorshavn, 61; first attempt at dredg- 525 img in deep water, 64; the ‘cold area,’ 69; the ‘warm area,’ 70; Stornoway, 76; general results of the cruise, 78. Littoral Zone, 15. Lituola, 115, 194. Lophohelia prolifera, 76, 169, 432. Lovén, Professor, additions to the know- ledge of marine zoology, 267; on bathy- metrical distribution: of submarine life, 269. Lyell, Siv Charles, Bart., F.R.S., on the cretaceous period, 472; on the con- tinuity of the chalk, 476, 491. Lyman, Theodore, memoirs in the ‘ Bul- letin of the Museum of Comparative Zoology,’ 277. M. M‘Clintock, Admiral Sir Leopold, voyage of the ‘ Bulldog,’ 24. Maury, M. F., LL.D., Captain U.S.N., 28; theory of ocean currents, 368; on the Gulf-stream, 383. May, Staff-Commander, cruise of the ‘ Lightning,’ 57, 304. Mean annual temperatures: Hebrides, 362; Labrador, 362; Bergen, 363; Tobolsk, 363; Fxroe Islands, 363 ; Falkland Islands, 363; Dublin, 363 ; Port Famine, 363 ; Halifax, 363; Bos- ton, 363. ‘Mercury,’ cruise of the, 233. Mune-Edwards, Alphonse, list of the animals found on the Mediterranean ee the depth of 1,100 fathoms, Mohn, Professor H., on surface and deep- sea temperatures on the west coast of Norway, 396. ae Otho Frederick, 237; his dredge, 239, Munida, 76, 161. N. Neolampas, 358; N. rostellatus, 469. Norman, Rev. A. Merle, addition to the Shetland fauna, 124; preliminary no- tice of the crustacea of the ‘ Porcupine’ aaa 176 ; Shetland dredgings, Nutrition of animals at great depths, 45. Nymphon abyssorum, 129, 0. Oceanic circulation, 79, 284; Dr. Car- penter’s theory of, 372. Ophiacantha spinulosa, 76, 148, 172. Ophiocten sericeum, 76, 123. Ophiomusium lymani, 172. Ophiopeltis securigera, 124. as purpurea, 123; O. glacialis, 526 Ophiothria littkent, 100. Orbitolites tenurssimus, 91, 194. Orbulina untversa, 23. P. Pecten hoskynst, 465. Pedicellaster typicus, 456. Pentacrinus wyville-thomsoni, 186, 443; P. asteria, 436; P. P. Miilleri, 442. Petermann, Dr., on the Gulf-stream, 287, 379, 392. Pheronema anne, 418. Phormosoma placenta, 171, 459. Phosphorescence, 98, 148. ag Professor, on the Gulf-stream, 386. Platydia anomioides, 146. Pleuronectia lucida, 464, 465. Polycystina, 98. ‘ Porcupine,’ first cruise of the, 82 ; equip- ment of the vessel, 83; results of the first dredging, 86; first trial of the Miller-Casella thermometers, 88; Por- cupine Bank, 88; trip to Rockall, 89 ; second cruise, 93; dredging at the depth of 2,435 fathoms, 95; return to Belfast, 100 ; third cruise, 101 ; olte- nia ground, 104; the hempen tangles, 105; Thorshayn, 106; discovery of Arctie stream, 110; Shetland plateau, 111; predominance of the Arctic fauna, 131; fauna of the warm area off the north coast of Scotland, 177; return to Belfast, 178; fourth cruise of the ‘Porcupine,’ 179; cruise in the Medi- terranean, 19); fauna near the African coast, 192; Adventure Bank, 192; Malta, 194; temperature soundings aoe Stromboli, 195 ; return to Cowes, 96. Porocidaris purpurata, 102, 459. Pourtales, Count L. F. de, deep-sea dredg- ings across the Gulf-stream off the coast of Florida, 277. Pourtalesia j-ffreysi, 108, 457, 459, 489 ; P. phiale, 90, 459, Predominance of protozoa, 47. Preservation of specimens, 261. Pressure, conditions of, at great depths, 32; methods of testing the actual pres- sure, 34; effect of pressure on the thermometer, 294. Prestwich, Joseph, F.R.S., President of the Geological Society : Temperatures of the Atlantic, 358; on the continuity of the chalk, 496. Psammechinus microtuberculatas, 457 ; P. miliaris, 459 Psolus syuamatus, 125. Prteraster militaris, 171. R, Rhabdammina abyssorum, 75. Rhaizocrinus loffotensis, 76, 124, 447, 451. INDEX. Richards, Rear-Admiral, C.B., F.R.S., Hydrographer to the Navy, 3. Ross, Sir James Clark, R.N., deep dredgings in the Antarctic Sea, 2U; temperature observations, 304. Ross, Sir John, voyage of discovery in Baffin’s Bay, 18; machine for taking up sounding'’s from great depths, 209 ; temperature observations during the Arctic voyage, 300. Rossella velata, 419. Royal Society, letter to, from Dr. Car- penter, recommending a systematic course of deep-sea dredging, 53; letter from the Secretary of, to the Secretary of the Admiralty, 55; reply from the Admiralty, 56 : (see also 133-141.) 8. Sabine, General Sir Edward, K.C.B., extracts from private journal, 18, 300. Sars, Professor Michael, list of animals of all the invertebrate groups living at a depth of 300 to 400 fathoms, 33, 268, 270, 274. Schizaster canaliferus, 459. Schmidt, Professor Oscar, on Hexactinel- lide, 70 ; Cometeila, 114, 268, 416. ee Professor Max, on Hyalonema, 425. Serpula, 273. Sharks at great depths, 34. Shortland, Captain, R.N., temperatures of deep water in the Arabian Sea, 359. Smith, Toulmin J., on Ventriculites, 482. poe Surcifer, 119, 456; S. papposus, Spatangus raschi, 118 ; 459 Spirorbis, 278. Spratt, Captain, R.N., dredging in the Mediterranean, 270. Steenstrup, Professor, additions to the knowledge of marine zoology, 268. Stylocordyla borealis, 114 Surface-temperature, mode of determin- ing the, 287; distribution of, in the North Atlantic, 362. S. purpureus, T. Tanks for the transportation of living fish, 59. Tellina calcaren, 462; T. compressa, 464. Ber pombats of the crust of the earth, Terebratula septata, 130. Pieeophet semisuberites, 147; T. bla, 148. Thecopsanmia socialis, 433. Thermometer, Six’s, 288 ; Miller-Casella, INDEX. 291 ; Breguet’s metallic thermometer, 293; Negretti and Zambra’s thermo- meter, 293. Thomson, Sir William, F.R.S., thermo- meter in a sealed glass tube, 296. Tisiphonia agariciformis, 74, 167. Toxopneustes brevispinosus, 459. Tripylus fragilis, 118, 459, y. Variation, 9. Ventriculites simplex, 483; outer surface, 484 ; section of the outer wall, 485. Verticordia acuticostata, 464. 527 w. Wallace, Alfred Russel, selection, 8. Waller, Edward, dredging off the South coast of Ireland, Hebrides, and Shet- land Islands, 121 ; on the fauna of the Hebrides, 267. Wallich, G. C., M.D., F.L.8., the North Atlantic Sea-bed, 24, 271, 302. Wright, Professor Perceval, deep dredg- ing off the coast of Portugal, 276. on natural Z. Zone of deep-sea corals, 16. Zoroaster fulgens, 153, THE END. LONDON : K, CLAY, SONS, AND TAYLOR, PRINTERS, BREAD STREET HILL. BEDFORD STREET, COVENT GARDEN, LONDON, Fanuary 1873. Macuiztan & Co’s Caratocue of Worxs im Maruemarics and Puystcat SCIENCE ; ncluding Pure and AppreD Marue- matics; Pxysics, Astronomy, GEOLOGY, Creurstey, Zootocy, Botany; Pxyvstotocy Anatomy and Mepicat Works generally ; and of Works tn Menrar and Morar Puitosopuy and Alked Subjects. MATHEMATICS. Airy.— Works by Sir G. B. Atry, K.C.B., Astronomer Royal :— ELEMENTARY TREATISE ON PARTIAL DIFFERENTIAL EQUATIONS. Designed for the Use of Students in the Univer- sities. With Diagrams. Crown 8vo. cloth. 55. 6d. It is hoped that the methods of solution here explained, and the in- stances exhibited, will be found sufficient for application to nearly all the important problems of Physical Science, which require for their complete investigation the aid of Partial Differential Equa- tions. ON THE ALGEBRAICAL AND NUMERICAL THEORY OF ERRORS OF OBSERVATIONS AND THE COMBINA- TION OF OBSERVATIONS. Crown 8vo. cloth. 6s. 6d. In order to spare astronomers and observers in natural philosophy the confusion and toss of time which are produced by referring to the ordinary treatises embracing both branches of probabilitees (the first Ex A 1750.1-73 2 * SCIENTIFIC CATALOGUE. Airy (G -B -)—continued. ' relating to chances which can be altered only by the changes of entire units or integral multiples of units in the fundamental conditions of the problem; the other concerning those chances which have respect to insensible gradations in the value of the element measured), this volume has been drawn up. It relates only to errors of observa- tion, and to the rules, derivable from the consideration of these errors, for the combination of the results of observations. UNDULATORY THEORY OF OPTICS. Designed for the Use of Students in the University. New Edition. Crown 8vo. cloth. 6s. 6d. The undulatory theory of optics is presented to the reader as having the same claims to his attention as the theory of gravitation,—namely, that it is certainly true, and that, by mathematical operations of general elegance, it leads to results of great interest, This theory explains with accuracy a vast variety of phenomena of the most complicated kind. The plan of this tract has been to include those phenomena only which admit of calculation, and the investigations are applied only to phenomena which actually have been observed. ON SOUND AND ATMOSPHERIC VIBRATIONS. With the Mathematical Elements of Music. Designed for the Use of Students of the University. Second Edition, revised and enlarged. Crown 8vo. 95. This volume consists of sections, which again are divided into num- bered articles, on the following topics :—General recognition of the air as the medium which conveys sound ; Properties of the air on which the formation and transmission of sound depend ; Theory of undulations as applied to sound, etc. ; Investigation of the motion of a wave of air through the atmosphere; Transmission of waves of soniferous vibrations through different gases, solids, and fluids ; Lxperiments on the velocity of sound, etc.; On musical sounds, and the manner of producing them; On the edements of musical harmony and melody, and of simple musical composition; On in- strumental music; On the human organs of speech and hearing. A TREATISE ON MAGNETISM. Designed for the Use of Students in the University. Crown 8vo. 9s. 6d. As the laws of Magnetic Force have been experimentally examined, MATHEMATICS. 3 with philosophical accuracy, only in its connection with tron and steel, and in the influence excited by the earth as a whole, the accurate portions of this work are confined to the investigations con- nected with these metals and the earth. The latter part of the work, however, treats in a more general way of the laws of the connection between Magnetism on the one hand and Galvanism and Thermo-Electricity on the other. The work ts divided into Twelve Sections, and each section into numbered urticles, each of which states concisely and clearly the subject of the following paragraphs. Ball (R. S., A.M.)—EXPERIMENTAL MECHANICS. A Course of Lectures delivered at the Royal College of Science for Ireland. By RoBERT STAWELL Batt, A.M., Professor of Applied Mathematics and Mechanics in the Royal College of Science for Ireland (Science and Art Department). Royal 8vo. 16s. The author's aim in these twenty Lectures has been to create in the mind of the student physical ideas corresponding to theoretical laws, and thus to produce a work which may be regarded either as a sup- plement or an introduction to manuals of theoretic mechanics, To vealize this design, the copious use of experimental illustrations was necessary. The apparatus used in the Lectures and figured in the volume has been principally built up from Professor Willis's most admirable system. In the selection of the subjects, the question of practical utility has in many cases been regarded as the one of para- mount importance, and it ts believed that the mode of treatment which ts adopted is more or less original. This ts especially the case in the Lectures relating to friction, to the mechanical powers, to the strength of timber and structures, to the laws of motion, and to the pendulum. The wlustrations, drawn from the apparatus, are nearly ail original and are beautifully exe- cuted. “In our reading we have not met with any book of the sort in English.” —Mechanics’ Magazine. Bayma.—THE ELEMENTS OF MOLECULAR MECHA- NICS. By JoserpH Baya, S.J., Professor of Philosophy Stonyhurst College. Demy 8vo. cloth. 105. 6d. Of the twelve Books into which this treatise is divided, the furst and second give the demonstration of the principles which bear directly on the constitution and the properties of matter. The next A2 4 SCIENTIFIC CATALOGUE. three books contain a series of theorems and of problencs on the laws of motion of elementary substances. In the sixth and seventh, the mechanical constitution of molecules ts investigated and determined: and by it the general properties of bodies are explained. The eighth book.treats of luminiferous ether. The ninth explains some special properties of bodies. The tenth and eleventh contain a radical and lengthy investigation of chemical principles and relations, which may lead to practical results of high importance. The twelfth and last book treats of molecular masses, distances, and powers. Boole.—wWorks by G. Booz, D.C.L, F.R.S., Professor of Mathematics in the Queen’s University, Ireland :— A TREATISE ON DIFFERENTIAL EQUATIONS. Third Edition. Edited byI. TopHUNTER. Crown 8vo. cloth. 145. Professor Boole has endeavoured in this treatise to convey as complete an account of the present state of knowledge on the subject of Dif- ferential Equations, as was consistent with the idea of a work in- tended, primarily, for elementary instruction. The earlier sections of each chapter contain that kind of matter which has usually been thought suitable for the beginner, while the latter ones are devoted either to an account of recent discovery, or the discussion of such deeper questions of principle as are likely to present themselves to the reflective student in connection with the methods and processes of his previous course. ‘‘A treatise incomparably superior to any other elementary book on the subject with which we are acquainted.’ — Philosophical Magazine. A TREATISE ON DIFFERENTIAL EQUATIONS. Supple- mentary Volume. Edited by I. TOoDHUNTER. Crown 8vo. cloth. 8s. 6d. This volume contains all that Professor Boole wrote for the purpose of enlarging his treatise on Differential Equations. THE CALCULUS OF FINITE DIFFERENCES. Crown 8vo. cloth. 10s. 6d. New Edition revised. Iu this exposition of the Calculus of Finite Differences, particular attention has been paid to the connection of its methods with those of the Differential Calculus —a connection which in some instances involves far more than a merely formal analogy. The workis in some measure designed as a sequel to Professor Boole's Treatise on Differential Equations. MATHEMATICS. be Brook-Smith (J).—ARITHMETIC IN THEORY AND PRACTICE. By J. Broox-Smiru, M.A., LL.B., St. John’s College, Cambridge; Barrister-at-Law ; one of the Masters of Cheltenham College. Crown 8vo. 45. 6d. Writers on Arithmetic at the present day feel the necessity of explaining the principles on which the rules of the subject are based, but few as yet feel the necessity of making these explanations strict and complete ; or, failing that, of distinctly pointing out their defective character. Lf the science of Arithmetic is to be made an effective instrument in developing and strengthening the mental powers, it ought to be worked out rationally and conclusively ; and in this work the author has endeavoured to reason out in u clear and accurate manner the leading propositions of the science, and to illustrate and apply those propositions in practice. In the practical part of the subject he has advanced somewhat beyond the majority of preceding writers; particularly in Division, in Greatest Common Measure, in Cube Root, in the chapters on Decimal Money and the Metric System, and more espectally in the application of Decimals to Per- centages and cognate suljects. Copious examples, original and selected, are given. Cambridge Senate-House Problems and Riders, WITH SOLUTIONS :— 1848-1851.—PROBLEMS. Fy FERRERS and JACKSON. 8vo. cloth. 15s. 6d. 1848-1851.—RIDERS. By Jassrson. 8vo. cloth. 7s. 6d. 1854.—PROBLEMS AND RIDERS. By Watron and MacKENZIE. 8vo. cloth. 105. 64. : 1857,—PROBLEM>s AND RIDERS. By Campion and WALTON. 8vo. cloth. 85. 6d. 1860.—PROBLEMS AND RIDERS. By Warson and RoutTH. Crown 8vo. cloth. 7s. 6d. 1864.—PROBLEMS AND RIDERS. By Watton and WIL- KINSON. 8vo. cloth. as. 6d. These volumes will be found of great value to Teachers and Students, as indicating the style ana range of mathematical study in the University of Cambridge. Cambridge and Dublin Mathematical Journal. The Complete Work, in Nine Vols. 8vo. cloth. 10/. Ios. 6 SCIENTIFIC CATALOGUE. Only a few copies remain on hand. Among contributors to this work will be found Sir W. Thomson, Stokes, Adams, Boole, Sir W. R. Hamilton, De Morgan, Cayley, Sylvester, Fellet, and other distinguished mathematicians. Cheyne.— Works by C. H. H. Cuevys, M.A., F.R.A.S.:— AN ELEMENTARY TREATISE ON THE PLANETARY THEORY. With a Collection of Problems. Second Edition. Crown 8vo. cloth. 6s. 6d. Ln this volume, an attempt has been madé to produce a treatise on the Planetary theory, which, being elementary in character, should be so far complete as to contain all that is usually required by students in the University of Cambridge. This Edition has been carefully revised. The stability of the Planetary System has been more fully treated, and an elegant g trical explanation of the formule for the secular variation of the node and inclination has been in- troduced. THE EARTH’S MOTION OF ROTATION. Crown 8vo, 35. 6d, The first part of this work consists of an application of the method of the variation of elements to the general problem of rotation. In the second part the general rotation formule are applied to the particular case of the earth. Childe.—THE SINGULAR PROPERTIES OF THE ELLIP- SOID AND ASSOCIATED SURFACES OF THE Nru DEGREE. By the Rev. G. F. Cuitpr, M.A., Author of “Ray Surfaces,” ‘ Related Caustics,” &c. 8vo. Ios. 6d. The object of this volume is to develop peculiarities in the Ellipsoid ; and, further, to establish analogous properties in the unlimited con- generic series of which this remarkable surface is a constituent. Dodgson.—AN ELEMENTARY TREATISE ON DETER. MINANTS, with their Application to Simultaneous Linear Equations and Algebraical Geometry. By CHarLes L. Dopcson, M.A., Student and Mathematical Lecturer of Christ Church, Oxford. Small 4to. cloth. tos. 6d. MATHEMATICS. 7 The object of the author is to present the subject as a continuous chain of argument, separated from all accessories of explanation of ulustration. All such explanation and illustration as seemed necessary for a beginner are introduced either in the form of Joot-notes, or, where that would have occupied too much room, of Appendices. Earnshaw (S., M.A.)—PARTIAL DIFFERENTIAL EQUATIONS. An Essay towards an entirely New Method of Integrating them. By S. EarnsHaw, M.A., of ‘St. John’s College, Cambridge. Crown 8vo. 5s. The peculiarity of the system expounded in this work is, that tn every equation, whatever be the number of original independent variables, the work of integration is at once reduced to the use of one indepen- dent variable only. The authors object is merely to render his method thoroughly intelligible. The various steps of the investiga- tion are all obedient to one general principle: and though in some degree novel, are not really difficult, but on the contrary, easy when the eye has become accustomed to the novelties of the notation. Many of the results of the integrations are far more general than they were in the shape in which they appeared in former Treatises, and many Equations will be found in this Essay integrated with ease in finite terms, which were never so integrated before. Ferrers.—AN ELEMENTARY TREATISE ON TRILINEAR CO-ORDINATES, the Method of Reciprocal Polars, and the Theory of Projectors. By the Rev. N. M. Fzrrers, M.A., Fellow and Tutor of Gonville and Caius College, Cambridge. ‘Second Edition. Crown 8vo. 6s. 6d. The object of the author in writing on this subject has mainly been to place it on a basis altogether independent of the ordinary Cartesian system, instead of regarding it as only a special form of Abridged Notation. A short chapter on Determinants has been introduced. Frost.—Works by PeRcivAL Frost, M.A., late Fellow of St. John’s College, Mathematical Lecturer of King’s College, Cam- bridge :— THE FIRST THREE SECTIONS OF NEWTON’S PRIN- CIPIA. With Notes and Illustrations, Also a Collection of _ Problems, principally intended as Examples of Newton’s Methods. Second Edition. 8vo. cloth. tos. 6d. 8 SCIENTIFIC CATALOGUE. Frost—continued. The author's principal intention is to explain difficulties which may be encountered by the student on first reading the Principia, and to Wlustrate the advantages of a careful study of the methods employed by Newton, by showing the extent to which they may,be applied in the solution of problems ; he has also endeavoured to give assistance to the student who is engaged in the stuly of the higher branches of mathematics, by representing in a geometrical form several of the processes employed in the Differential and Integral Calculus, and in the analytical investigations of Dynamics. AN ELEMENTARY TREATISE ON CURVE TRACING. 8vo. 125. The author has written this book under the conviction that the skill and power of the young mathematical student, in order to be thoroughly available afterwards, ought to be developed in all possible directions. The subject which he has chosen presents so many faces, pointing in directions towards which the mind of the intended mathematician has to radiate, that it would be difficult to find another which, with a very limited extent of reading, combines, to the same extent, so many valuable hints of methods of calculations to be employed hereafter, with so much pleasure in its present use. In order to understand the work it ts not necessary to have much knowledge of what is called Higher Algebra, nor of Algebraical Geometry of a higher kind than that which simply relates to the Conic Sections. From the study of a work like this, it ts believed that the student will derive many advantages. Especially he will become skilled in making correct approximations to the values of quantities, which cannot be found exactly, to any degree of accuracy which may be required. Frost and Wolstenholme.—a TREATISE ON SOLID GEOMETRY. By Percival Frost, M.A., and the Rev. J. WOLSTENHOLME, M.A., Fellow and Assistant Tutor of Christ’s College. 8vo. cloth. 18s. ; Intending to make the subject accessible, at least in the earlier portions to all classes of students, the authors have endeavoured to explain completely all the processes which are most useful in dealing with ordinary theorems ana problems, thus directing the student to the selection of methods which are best adapted to the exigencies of each problem. In the more difficult portions of the subject, they have conswuered themselves to be addressing a higher class of students ; MATHEMATICS. 9 and they have there tried to lay a good foundation on which to build, if any reader should wish to pursue the science beyond the limits to which the work extends. Godfray.— Works by HucH Goprray, M.A., Mathematical Lecturer at Pembroke College, Cambridge :— A TREATISE ON ASTRONOMY, for the Use of Colleges and Schools. 8vo. cloth. 12s. 6d. This book embraces all those branches of Astronomy which have, from time to time, been recommended by the Cambridge Board of Mathe- matical Studies: but by far the larger and easier portion, adapted to the first three days of the Examination for Honours, may be read by the more advanced pupils in many of our schools. The author's aim has been to convey clear and distinct ideas of the celestial phe- nomena. ‘“‘It is a working book,” says the Guardian, “‘ taking Astronomy in its proper place in the Mathematical Sciences... . It is a book which is not likely to be got up unintelligently.” AN. ELEMENTARY TREATISE ON THE LUNAR THEORY, with a Brief Sketch of the Problem up to the time of Newton. Second Edition, revised. Crown 8vo. cloth. 55. 6d. These pages will, wt is hoped, form an introduction to more recondite works, Difficulties have been discussed at considerable length. The selection of the method followed with regard to analytical solutions, which ts the same as that of Airy, Herschel, etc., was made on account of its simplicity ; it ts, moreover, the method which has obtained in the University of Cambridge. ‘‘ As an elementary treatise and introduction to the sulject, we think it may justly claim to supersede all former ones.” —London, Edinburgh, and Dublin Phil. Magazine. Green (George).—_MATHEMATICAL PAPERS OF THE LATE GEORGE GREEN, Fellow of Gonville and Caius College, Cambridge. Edited by N. M. Ferrers, M.A., Fellow and Tutor of Gonville and Caius College. 8vo. 155. The publication of this book may be opportune at present, as several of the subjects with which they are directly or indirectly concerned have recently been introduced into the course of mathematical i study at Cambridge. They have also an interest as being the work of an almost entirely self-taught mathematical genius. The Papers 10 SCIENTIFIC CATALOGUE. comprise the following :—An Essay on the application of Mathe- matical Analysis to the Theories of Electricity and Magnetism— On the Laws of the Equilibrium of Fluids analogous to the Electric #luid—On the Determination of the Attractions of Ellipsoids of variable Densities—On the Motion of Waves in a variable Canal of small depth and width—On the Reflection and Refraction of Sound—On the Reftection and Refraction of Light at the Common Surface of two Non-Crystallized Media—On the Propagation of Light in Crystallized Media—Researches on the Vibrations of Pen- dulums in Fluid Media. ‘“‘ It has been for some time recognized that Green’s writings are amongst the most valuable mathematical productions we possess.” —Athenzeum. Hemming.—AN ELEMENTARY TREATISE ON THE DIFFERENTIAL AND INTEGRAL CALCULUS. For the Use of Colleges and Schools. By G. W. Hemminc, M.A, Fellow of St. John’s College, Cambridge. Second Edition, with Corrections and Additions. 8vo. cloth. 9s. “ There is no book in common use Srom which so clear and exact a knowledge of the principles of the Calculus can be so readily ob- tained.” —Literary Gazette. Jackson.—GEOMETRICAL CONIC SECTIONS. An Ele- mentary Treatise in which the Conic Sections are defined as the Plane Sections of a Cone, and treated by the Method of Projections. By J. STuART JACKSON, M.A, late Fellow of Gonville and Caius College. Crown 8vo. 45. 6d. This work has been written with a view to give the student the benefit of the Method of Projections as applied to the Ellipse and Hyper- bola. When this method is admitted into the treatment of Conic Sections there are many reasons why they should be defined, not with reference to the focus and directrix, but according to the original definition from which they have their name, as Plane Sections of a Cone. This method ts calculated to produce a material simplification in the treatment of these curves and to make the proof of their properties more easily understood in the first instance and nore easily remembered. It is also a powerful instrument in the solution of a large class of problems relating to these curves. MATHEMATICS. II Morgan.—A COLLECTION OF PROBLEMS AND EXAM- PLES IN MATHEMATICS. With Answers. By H. A. Morecan, M.A., Sadlerian and Mathematical Lecturer of Jesus College, Cambridge. Crown 8vo. cloth. 6s. 6d. This book contains a number of problems, chiefly elementary, in the Mathematical subjects usually read at Cambridge. They have been selected from the Papers set during late years at Fesus College. Very Jew of them are to be met with in other collections, and by far the larger number are due to some of the most distinguished Mathe- maticians in the University. Newton’s Principia. 4to. cloth. 31s. 6d. It is a sufficient guarantee of the reliability of this complete edition of Newton's Principia that it has been printed for and under the care of Professor Sir William Thomson and Professor Blackburn, of Glasgow University. The following notice is prefixed :—‘* Finding that all the editions of the Principia are now out of print, we have been induced to reprint Newton's last edition (of 1726] without note or comment, only introducing the ‘Corrigenda’ of the old copy and correcting typographical errors.” The book is of a handsome size, with large type, fine thick paper, and cleanly-cut figures, and is the only recent edition containing the whole of Newton's great work, Parkinson.—Works by §$. Parkinson, D.D., F.R.S., Fellow and Tutor of St. John’s College, Cambridge :— AN ELEMENTARY TREATISE ON MECHANICS. For the Use of the Junior Classes at the University and the Higher Classes in Schools. With a Collection of Examples. Fourth Edition, revised. Crown 8vo. cloth. 9s. 6d. In preparing a fourth edition of this work the author has kept the same object in view as he had in the former editions—namely, to in- clude in it such portions of Theoretical Mechanics as can be con- veniently investigated without the use of the Differential Calculus, and so render it suitable as a manual for the junior classes in the University and the higher classes in Schools. With one or two short exceptions, the student is not pr d to require a knowledge of any 12 SCIENTIFIC CATALOGUE. Parkinson—continued. branches of Mathematics beyond the elements of Algebra, Geometry, and Trigonometry. Several additional propositions have been in- corporated in the work for the purpose of rendering it more complete, and the collection of Examples and Problems has been largely in- creased. A TREATISE ON OPTICS. Third Edition, revised and en- larged. Crown 8vo. cloth. 10s. 6d. A collection of Examples and Problems has been appended to this work, which ave sufficiently numerous and varied in character to afford useful exercise for the student. For the greater part of them, re- course has been had to the Examination Papers set in the University and the several Colleges during the last twenty years. Phear.—ELEMENTARY HYDROSTATICS. With Numerous Examples. By J. B. PHrar, M.A., Fellow and late Assistant Tutor of Clare College, Cambridge. Fourth Edition. Crown 8vo. cloth. 55. 6d. This edition has been carefully revised throughout, and many new Illustrations and Examples added, which it is hoped will increase its usefulness to students at the Universities and in Schools. Jn ac- cordance with suggestions from many engaged in tuition, answers to all the Examples have been given at the end of the book. Pratt.—A TREATISE ON ATTRACTIONS, LAPLACE’S FUNCTIONS, AND THE FIGURE OF THE EARTH. By Joun H. Pratt, M.A., Archdeacon of Calcutta, Author of ‘«The Mathematical Principles of Mechanical Philosophy.”’ Feurth Edition. Crown 8vo. cloth. 6s. 6d. The author's chief design in this treatise ts to give an cmswer to the question, ‘‘Has the Earth acquired its present form from being originally in a fluid state?” This edition ts a complete revision of the former ones. Puckle.—AN ELEMENTARY TREATISE ON CONIC SEC- TIONS AND ALGEBRAIC GEOMETRY. With numerous Examples and Hints for their Solution ; especially designed for the Use of Beginners. By G. H. Puckie, M.A., Head Master of Windermere College. New Edition, revised and enlarged. Crown 8vo, cloth. 75. 6d. MATHEMATICS. 13 This work is recommended by the Syndicate of the Cambridge Local Examinations, and ts the text-book in Harvard University, U.S. The Athenzeum says the author ‘displays an intimate acquaint. ance with the difficulties likely to be felt, together with a singular aptitude in removing them.” Routh.—AN ELEMENTARY TREATISE ON THE DYNA- MICS OF THE SYSTEM OF RIGID BODIES. With numerous Examples. By EDwarpD JoHN RoutH, M.A., late Fellow and Assistant Tutor of St. Peter’s College, Cambridge ; Examiner in the University of London. Second Edition, enlarged. Crown 8vo. cloth. 145. In this edition the author has made several additions to each chapter: he has tried, even at the risk of some little repetition, to make each chapter, as far as possible, complete in itself, so that all that relates to any one part of the subject may be found in the same place. This arrangement will enable every student to select his own order in which to read the subject. The Examples which will be found at the end of each chapter have been chiefly selected from the Examina- tion Papers which have been set in the University and the Colleges in the last few years. Smith’s (Barnard) Works.—sSee EpucationaL Cata- LOGUE, Snowball.—THE ELEMENTS OF PLANE AND SPHERT- CAL TRIGONOMETRY ; with the Construction and Use of Tables of Logarithms. By J. C. Snowspai1, M.A. Tenth Edition. Crown 8vo. cloth. 7s. 6d. In preparing the present edition for the press, the text has been sub- jected to a careful revision ; the proofs of some of the more import- ant propositions have been rendered more strict and general ; and a considerable addition of more than two hundred examples, taken principally from the questions set of late years in the public exami- nations of the University and of individual Colleges, has been made to the collection of Examples and Problems for practice. 14 SCIENTIFIC CATALOGUE. Tait and Steele.—DYNAMICS OF A PARTICLE. With numerous Examples. By Professor Tair and Mr. STEELE. New Edition. Crown 8vo. cloth. 10s. 6d. In this treatise will be found all the ordinary propositions, connected with the Dynamics of Particles, which can be conveniently deduced without the use of D’ Alembert’s Principle. Throughout the book will be found a number of illustrative examples introduced in the text, and for the most part completely worked out ; others with occa- stonal solutions or hints to assist the student are appended to each chapter. For by far the greater portion of these, the Cambridge Senate-House and College Examination Papers have been applied to, Taylor.—GEOMETRICAL CONICS; including Anharmonic Ratio and Projection, with numerous Examples. By C. Tayor, B.A., Scholar of St. John’s College, Cambridge. Crown 8vo. cloth. 7s. 6d. This work contains elementary proofs of the principal properties of Conic Sections, together with chapters on Projection and Anharmonic Ratio, Todhunter.—Works by I. TopHunTeR, M.A., F.R.S., of St. John’s College, Cambridge :— “‘Perspicuous language, vigorous investigations, scrutiny of difficulties, and methodical treatment, characterize Mr. Todhunter’s works,” — Civil Engineer. THE ELEMENTS OF EUCLID; MENSURATION FOR BEGINNERS; ALGEBRA FOR BEGINNERS; TRIGO- NOMETRY FOR BEGINNERS; MECHANICS FOR BEGINNERS.—See EDUCATIONAL CATALOGUE. ALGEBRA. For the Use of Colleges and Schools. Fifth Edition. Crown 8vo. cloth. 7s. 6d. This work contains all the propositions which are usually included in elementary treatises on Algebra, and a large number of Examples for Exercise. The author has sought to render the work easily in- telligible to students, without impairing the accuracy of the demon- strations, or contracting the limits of the subject. The Examples, about Sixteen hundred and fifty i number, have been selected with MATHEMATICS. 15 Todhunter (I.)—continued. a view to illustrate every part of the subject. The work will be found peculiarly adapted to the wants of students who are without the aid of a teacher. The Answers to the Examples, with hints for the solution of some in which assistance may be needed, are given at the end of the book. In the present edition two New Chapters and Three hundred miscellaneous Examples have been added. “It has merits which unquestionably place it first in the class to which it belongs.”’—Educator. KEY TO ALGEBRA FOR THE USE OF COLLEGES AND SCHOOLS. Crown 8vo. 10s. 6d. AN ELEMENTARY TREATISE ON THE THEORY OF EQUATIONS. Second Edition, revised. Crown 8vo. cloth. 7s. Od. This treatise contains all the propositions which are usually included in elementary treatises on the theory of Equations, together with Examples for exercise. These have been selected from the College and University Examination Papers, and the results have been given when tt appeared necessary. In order to exhibit a compre- hensive view of the subject, the treatise includes investigations which are not found in all the preceding elementary treatises, and also some investigations which are not to be found in any of them. For the second edition the work has been revised and some additions have been made, the most important being an account of the Researches of Professor Sylvester respecting Newton's Rule. ‘A thoroughly trustworthy, complete, and yet not too elaborate treatise.” —Philosophical Magazine. PLANE TRIGONOMETRY. For Schools and ae Fourth Edition. Crown 8vo. cloth. 55. The design of this work has been to render the subject intelligible to beginners, and at the same time to afford the student the oppor- tunity of obtaining all the information which he will require on this branch of Mathematics. Each chapter is followed by a set of Examples: those which are entitled Miscellaneous Examples, together with a few in some of the other sets, may bé advantageously reserved by the student for exercise after he has made some progress in the subject. In the Second Edition the hints for the solution of the Examples have been considerably increased, 16 SCIENTIFIC CATALOGUE. Todhunter (I.)—continued. A TREATISE ON SPHERICAL TRIGONOMETRY. Third Edition, enlarged. Crown 8vo. cloth. 45. 6d. The present work ts constructed on the same plan as the treatise on Plane Trigonometry, to which it ts intended as a sequel. In the account of Napier’s Rules of circular parts, an explanation has been given of a method of proof devised by Napier, which seems to have been overlooked by most modern writers on the subject. Con- siderable labour has been bestowed on the text in order to render it comprehensive and accurate, and the Examples (selected chiefly from College Examination Papers) have all been carefully verified. “* For educational purposes this work seems to be superior lo any others on the subject.” —Critic. PLANE CO-ORDINATE GEOMETRY, as applied to the Straight Line and the Conic Sections. With numerous Examples. Fourth Edition, revised and enlarged. Crown 8vo. cloth. 75. 6d. The author has here endeavoured to exhibit the subject in u simple manner for the benefit of beginners, and at the same time to include in one volume all that students usually require. In addition, therefore, to the propositions which have always appeared in such treatises, he has introduced the methods of abridged notation, which are of more recent origin: these methods, which are of a less elementary character than the vest of the work, are placed in separate chapters, and may be omitted by the student at first. A TREATISE ON THE DIFFERENTIAL CALCULUS. With numerous Examples. Fifth Edition, Crown 8vo. cloth. los. 6a. The author has endeavoured in the present work to exhibit a compre. hensive view of the Differential Calculus on the method of limits. In the more elementary portions he has entered into considerable detail in the explanations, with the hope that a reader who ts without the assistance of a tutor may be enabled to acquire a competent ac- quaintance with the subject. The method adopted is that of Dif- Jerential Coefficients. To the different chapters ave appended Examples sufficiently numerous to render another book unnecessary ; these Examples being mostly selected from College Examination Papers. This and the following work have been translated into MATHEMATICS. 17 continued. Todhunter (I.) italian by Professor Battaglini, who in his Preface speaks thus :— ‘In publishing this translation of the Differential and Integral Calculus of Mr. Todhunter, we have had no other object than to add to the books which are in the hands of the students of our Uni- versities, a work remarkable for the clearness of the exposition, the rigour of the demonstrations, the just proportion in the parts, wil the rich store of examples which offer a large fied for useful exercise.” , A TREATISE ON THE INTEGRAL CALCULUS AND ITS APPLICATIONS. With numerous Examples. Third Edition, revised and enlarged. Crown 8vo. cloth. tos. 6d. This is designed as a work at once elementary and complete, adapted Sor the use of beginners, and sufficient for the wants of advanced students. In the selection of the propositions, and in the mode of establishing them, it has been sought to exhibit the principles clearly, and to illustrate all their most important results. The process of summation has been repeatedly brought forward, with the view of securing the attention of the student to the notions which form the true foundation of the Calculus itself, as well as of its most valuable applications. Every attempt has been made to explain those difficulties which usually perplex beginners, especially with reference to the limits of integrations. A new method has been adopted in vegard to the transformation of multiple integrals. The last chapter deals with the Calculus of Variations. A large collection of Exer- ctses, selected from College Examination Papers, has been appended to the several chapters. EXAMPLES OF ANALYTICAL GEOMETRY OF THREE DIMENSIONS. Third Edition, revised. Crown 8vo. cloth. 4». A TREATISE ON ANALYTICAL STATICS. With numerous Examples. Third Edition, revised and enlarged. Crown 8vo. cloth. 10s. 6d. In this work on Statics (treating of the laws of the equilibrium of bodies) will be found all the propositions which usually appear in treatises on Theoretical Statics. To the different chapters Examples are appended, which have been principally selected from University Examination Papers. In the Third Edition many additions have been made, in order to illustrate the application of the principles of the subject to the solution of problems. B 18 SCIENTIFIC CATALOGUE. Todhunter (1.)—continucd. A HISTORY OF THE MATHEMATICAL THEORY OF PROBABILITY, from the Time of Pascal to that of Laplace. 8vo. 185. The subject of this work has high claims to consideration on account of the subile problems which it involves, the valuable contributions to analysis which it has produced, its important practical applica- tions, and the eminence of those who have cultivated it; nearly every great mathematician within the range of a century and a half comes under consideration in the course of the history. The author has endeavoured to be quite accurate in his statements, and to reproduce the essential elements of the original works which he has analysed. Besides being a history, the work may claim the title of a comprehensive treatise on the Theory of Probability, for it assumes in the reader only so much knowledge as can be gained from an elementary book on Algebra, and introduces hin to almost every process and every special problem which the literature of the subject can furnish. RESEARCHES IN THE CALCULUS OF VARIATIONS, Principally on the Theory of Discontinuous Solutions: An Essay to which the Adams’ Prize was awarded in the University of Cambridge in 1871. 8vo. 6s. The subject of this Essay was prescribed in the following terms by the £. s:— “A determination of the circumstances under which discontinuity of any kind presents itself in the solution of a problem of max or 1 in the Calculus of Variations, and applications to particular instances. It is expected that the discus- sion of the instances should be exemplified as far as possible geo- metrically, and that attention be especially directed to cases of real or supposed failure of the Calculus.” While the Essay ts thus mainly devoted to the consideration of discontti Ss solutions, various other questions in the Calculus of Variations are examined and elucidated ; and the author hopes he has definitely contributed to the extension and tmpr t of our knowledge of this refined depart- ment of analysis. Wilson (W. P.)—A TREATISE ON DYNAMICS. By W. P. Witson, M.A., Fellow of St. John’s College, Cambridge, and Professor of Mathematics in Queen’s College, Belfast. 8vo. gs. 6x. MATHEMATICS. 19 Wolstenholme.—A BOOK OF MATHEMATICAL PROBLEMS, on Subjects included in the Cambridge Course. By JosepH WoLsTENHOLME, Fellow of Christ’s College, some time Fellow of St. John’s College, and lately Lecturer in Mathe- matics at Christ’s College. Crown 8vo. cloth. 8». 6d. CONTENTS :—Geometry (Euclid )—Algebra—Flane Trigonometry— Geometrical Conic Sections—Analytical Conic Sections—Theory o } Equations—Differential Calculus—Integral Calculus—Solid Geo- metry—Statics—Elementary Dynamics—Newton—Dynamics of a Point—Dynamics of a Rigid Body—Hydrostatics— Geometrical Optics—Spherical Trigonometry and Plane Astronomy. In some cases the author has prefixed to certain classes of problems frag- mentary notes on the mathematical subjects to which they relate, * Sudicious, symmetrical, and well arranged.” —Guardian. B2 20 SCIENTIFIC CATALOGUE. PHYSICAL SCIENCE. Airy (G. B.)—POPULAR ASTRONOMY. With Illustrations By Sir G. B. Airy, K.C.B., Astronomer Royal. Seventh and cheaper Edition. 18mo. cloth. 45. 6d. This work consists of Six Lectures, which are intended ‘to explain to intelligent persons the principles on which the instruments of an Observatory are constructcd (omitting all details, so far as they are merely subsidiary), and the principles on which the observations made with these instruments are treated for deduction of the distances and weights of the bodies of the Solar System, and of a few stars, omitting all minutia of formule, and all troublesome details of calculation.” The speciality of this volume is the direct reference of every step to the Observatory, and the full description of the methods and instruments of observation. Bastian.—Works by H. Cuartron BasTIAN, M.D., F.R.S., Professor of Pathological Anatomy in University College, London, etc, :— THE MODES OF ORIGIN OF LOWEST ORGANISMS: Including a Discussion of the Experiments of M. Pasteur, and a Reply to some Statements by Professors Huxley and Tyndall. Crown 8vo. 45. 6:2. The present volume contains a fragment of the evidence which will be embodied in a much larger work—now almost completed—relating to the nature and origin of living matter, and in favour of what is termed the Physical Doctrine of Life. “‘ It is a work worthy of the highest respect, and places its author in the very first class of scientific physicians. . . . Lt would be difficult to name an instance in which shill, knowledge, perseverance, and great reasoning power have been more happily applied to the investigation of a complex biological problem.” —British Medical Journal. PHYSICAL SCIENCE. 21 Bastian (H. C.)—continued. THE BEGINNINGS OF LIFE: Being some Account of the Nature, Modes of Origin, and Transformations of Lower Organ- isms. In Two Volumes. With upwards of 100 Illustrations. Crown 8vo. 28s, The subject of this work is one of the highest interest not only to scientific men, but to intelligent men of all kinds. Dr. Bastian’s labours in this atrection are already well known and highly valued, even by those who differ from his conclusions. These volumes con- tain the results of several years’ investigation on the Origin of Life, and it was only atfer the author had proceeded some length with Aus observations and experiments that he was compelled to change the opinions he started with for those announced in the present work —the most important of which is that in favour of “ spontaneous generation” —the theory that life has never ceased to be actually originated. The First Part of te ork is intended to show the general reader, more especially, that the logical consequences of the now commonly accepted doctrines concerning the ** Conservation of Energy” and the ** Correlation of the Vital and Physical Forces” are wholly favourable to the possibility of the independent origin of “Living” matter. It also contains 'a view of the ** Cellular Theory of Organisation.” In the Second Part of the work, under the head ‘* Archebiosis,” the question as to the present occurrence or non-occurrence of “ spontancous generation” ts fully considered. “* He has made a notable contribution to the literature of scientific research and exposition.”—Daily News. ‘“‘ft is a book thai cannot be ignored, and must inevitably ad to renewed discussions and repeated observations, and through chese to the establishment of truth.” —A, R. WALLACE iz Nature. Birks (T. R.)}—ON MATTER AND ETHER ; or, The Secret Laws of Physical Change. By TH7MAs Rawson Birks, M.A., Professor of Moral Philosophy in the University of Cambridge. Crown 8vo. 55. 6d. The author believes that the hypothesis of the existence of, besides matter, a luminous ether, of se lastes force, supplies the true and suf- ficient hey to the remaining secrets of inorganic matter, of the phe- nomena of light, electricity, ec. In this treatise the author endea- vours first to form a clear and atfinite concep'ion with regard to the 22 SCIENTIFIC CATALOGUE. veal nature both of matter and ether, and the laws of mutual action which must be supposed to exist bete them. He then endeavours to trace out the main conseg es of the fund tal hypothesis, and their correspondence with the known phenomena of physical change. Blanford (W. T.)—GEOLOGY AND ZOOLOGY OF ABYSSINIA. By W. T. BLanrorp. 8vo. 21s. This work contains an account of the Geological and Zoological Obser- vations made by the author in Abyssinia, when accompanying the British Army on its march to Magdala and back in 1868, and during a short journey in Northern Abyssinia, after the departure of the troops. Part I. Personal Narrative; Part If. Geology ; Part IMI. Zoology. With Coloured Illustrations and Geological Map. ‘The result of his labours,” the Academy says, ‘is an important contribution to the natural history of the country.” Cooke (Josiah P., Jun.)—FIRST PRINCIPLES OF CHEMICAL PHILOSOPHY. By Jostan P. Cooke, Jun., Ervine Professor of Chemistry and Mineralogy in Harvard College. Crown 8vo. 125. The object of the author in this book ts to present the philosophy of Chemistry in such a form that it can be made with profit the subject of College recitations, and furnish the teacher with the means of testing the student’s faithfulness and ability. With this view the subject has been developed in a logical order, and the principles of the science are taught independently of the experimental evidence on swhsch they rest. Cooke (M. C.)—HANDBOOK OF BRITISH FUNGI, with full descriptions of all the Species, and Illustrations of the Genera, By M.C, CookE, M.A. Two vols. crown 8vo. 245. During the thirty-fiwe years that have edapsed since the appearance of the last complete Mycologic Flora no attempt has been made to revise it, to incorporate species since discovered, and to bring it up to the standard of modern science. No apology, therefore, ts necessary for the present effort, since all will admit that the want of such a PHYSICAL SCIENCE. "a3 manual has long been felt, and this work makes its appearance under the advantage that it seeks to occupy a place which has long been vacant. No effort has been spared to make the work worthy of confidence, and, by the publication of an occasional supplement, wt is hoped to maintain it for many years as the “‘ Handbook jor every student of British Fungi. Appended is a complete alpha- betical Index of all the divisions and subdivisions of the Fungi noticed in the text. The book contains 400 figures. “ Will main- tain its place as the standard English book, on the subject of which ut treats, for many years to come.” —Standard. . Dawson (J. W.)—ACADIAN GEOLOGY. The Geologic Structure, Organic Remains, and Mineral Resources of Nova Scotia, New Brunswick, and Prince Edward Island. By Joun Wituram Dawson, M.A., LL.D., F.R.S., F.G.S., Principal and Vice-Chancellor of M‘Gill College and University, Montreal, &c. Second Edition, revised and enlarged. With 4 Geological Map and numerous Illustrations. 8vo. 18s. The object of the first edition of this work was to place within the reach of the people of the districts to which it relates, a popular account of the more recent discoveries in the geology and mineral vesources of their country, and at the same time to give to geologists in other countries a connected view of the structure of a very in- teresting portion of the American Continent, in its relation to general and theoretical Geology. In the present edition, it is hoped this design ws stall more completely fulfilled, with reference to the present more advanced condition of knowledge. The author has endea- woured to convey a knowledge of the stricture and fossils of the region in such a manner as to be inielligible to ordinary readers, and has devoted much attention to all questions relating to the nature and present or prospective value of deposits of useful minerals. Besides a large coloured Geological Map of the district, the work zs illustrated by upwards of 260 cuts of sections, fossils, animals, ate. ‘*The book will doubtless find a place in the library, not only of the scientific geologist, but also of all who are desirous of the tn- dustrial progress and commercial prosperity of the Acadian pro- vinces.”—Mining Journal. ‘‘A style at once popular and scientific. ... 4 valuable addition to our store of geological knowledge.” — Guardian. 24 SCIENTIFIC CATALOGUE. Flower (W. H.)—AN INTRODUCTION TO THE OSTE- OLOGY OF THE MAMMALIA. Being the substance of the Course of Lectures delivered at the Royal College of Surgeons of England in 1870. By W. H. FLower, F.R.S., F.R.C.S., Hunterian Professor of Comparative Anatomy and Physiology. With numerous Illustrations. Globe 8vo. 7s. 6d. Although the present work contains the substance of a Course of Lectures, the form has been changed, so as the better to adapt it as a hand- book for students. Theoretical views have been almost entirely ex- cluded : and while it 1s impossible in a scientific treatise to avoid the employment of technical terms, it has been the author's endeavour to use no more than absolutely necessary, and lo exercise due care in selecting only those that seem most appropriate, or which have re- ceived the sanction of general adoption. With a very few excep- tions the tilustrations have been drawn expressly for this work from specimens tn the Museum of the Royal College of Surgeons. Galton.—Works by Francis Garon, F.R.S. :— METEOROGRAPHICA, or Methods of Mapping the Weather. Illustrated by upwards of 600 Printed Lithographic Diagrams. 4to. 95. As Mr. Galton entertains strong views on the necessity of Meteorolo- gical Charts and Maps, he determined, as a practical proof of what could be done, to chart the entire area of Europe, so far as meteorological stations extend, during one month, viz. the month of December, 1861. Mr. Galton got his data from authorities in every part of Britain and the Continent, and on the basis of these has here drawn up nearly a hundred different Maps and Charts, showing the state of the weather all over Europe during the above period. *‘ If the various Gover ts and scientific bodies ld perform for the whole world for two or three years what, at a great cost and labour, Mr. Galton has done for a part of Europe for one month, Meteoro- logy would soon cease to be made a joke of.” —Spectator. HEREDITARY GENIUS: An Inquiry into its Laws and Con- sequences. Demy 8vo. 12s. ‘I propose,” the author says, ‘‘to show in this book that « man's natural abilities are derived by inheritance, under exactly the same PHYSICAL SCIENCE. 25 limitations as ave the form and physical features of the whole organic world. I shall show that social agencies of an ordinary character, whose influences are little suspected, are at this moment working towards the degradation of human nature, and that others are working towards its improvement. The general plan of my argu- ment ts to show that high reputation is a pretty accurate test of high ability ; next, to discuss the relationships of a large body of fairly eminent nen, and to obtain from these a general survey of the laws of heredity in respect of genius. Then will follow a short chapter, by way of comparison, on the hereditary transmission of physical gifts, as deduced from the relationships of certain classes of oarsmen and wrestlers. Lastly, 1 shall collate my results and draw conclu- sions.” The Times calls it ‘‘a most able and most interesting book ;” and Mr. Darwin, zz his “‘ Descent of Man” (vol. i. p. 111), says, “‘ We know, through the admirable labours of Mr. Galion, that Genius tends to be inherited.” Geikie (A.)—SCENERY OF SCOTLAND, Viewed in Connec- tion with its Physical Geography. With Illustrations and a new Geological Map. By ARCHIBALD GEIKIE, Professor of Geology in the University of Edinburgh. Crown 8vo. Ios. 6d. “* We can confidently recommend Mr. Geikie's work to those who wish to look below the surface and read the physical history of the Scenery of Scotland by the light of modern science.” —Saturday Review. “* Amusing, picturesque, and instructive.” —Times. Guillemin.—THE FORCES OF NATURE: A Popular Intro- duction to the Study, of Physical Phenomena. By AM&DSE GUILLEMIN. ‘Translated from the French by Mrs. NorRMAN Lockyer ; and Edited, with Additions and Notes, by J. NORMAN Lockyer, F.R.S. Illustrated by 11 Coloured Plates and 455 Woodcuts. Imperial 8vo. cloth, extra gilt. 315. 6d. MM. Guillemin is already well known in this country as a most success- ful populariser of the results of accurate scientific research, his works, while eloquent, intelligible, and interesting to the general reader, being thoroughly trustworthy and up to date. The present work consists of Seven Books, each divided into a number of . Chapters, the Books treating respectively of Gravity, Sound, Light, Heat, Magnetism, Electricity, and Atmospheric Meteors. 26 SCIENTIFIC CATALOGUE. The programme of the work has not been confined to u simple explanation of the facts: but an attempt has been made to grasp their relative bearings, or, in other words, their laws, and that too without taking for granted that the reader is acquainted with mathematics. The author's aim has been to smooth the way Jor those who desire to extend their studies, and likewise to present to general readers a sufficiently exact and just idea of this branch of science. The numerous coloured illustrations and woodcuts are not brought into the text merely for show, but each one is reaily illas- trative of the subject. The name of the translator and editor is a sufficient guarantee both that the work ts of genuine scientific value and that the translation ts accurate and executed with intelligence. “* This book ts a luxurious introduction to the study of the Physical Sciences. M. Guillemin has found an excellent translator in Mrs. Norman Lockyer, while the editorship of My. Norman Lockyer, with his notes and additions, are guarantees not only of scientific accuracy, but of the completeness and lateness of the information.” —Daily News. « Hooker (Dr.)—THE STUDENT’S FLORA OF THE BRITISH ISLANDS. By J. D. Hooxer, CB. F.RS., M.D., D.C.L., Director of the Royal Gardens, Kew. Globe 8vo. 10s. 6d. The object of this work ts to supply students and field-botanists with a Suller account of the Plants of the British Islands than the manuals hitherto in use aim at giving. The Ordinal, Generic, and Specific characters have been re-written, and are to a great extent original, and drawn from living or dried specimens, or both. ** Cannot fail to perfectly fulfil the purpose for which it is intended.”—Land and Water. ‘‘ Containing the fullest and most accurate manual of the kind that has yet appeared.” —Pall Mall Gazette. Huxley (Professor).—LAy SERMONS, ADDRESSES, AND REVIEWS. By T. H. Huxiey, LL.D., F.RS. New and Cheaper Edition. Crown 8vo. 7s. 6d. Fourteen Discourses on the following subjects:—(1) On. the Advisable- ness of Improving Natural Knowledge :—(2) Emancipation— Black and White :—(3) A Liberal Education, and where to find it:—(4). ScientificEducation:—(5) On the Educational Value of PHYSICAL SCIENCE. 27 Huxley (Professor).—continued. the Natural History Sciences:—(6) On the Study of Zoology:— (7) On the Physical Basis of Life:—(8) The Scientific Aspects of Positivism :—(9) On «a Piece of Chalk:—(10) Geological Contem- poraneity and Persistent Types of Life:—(11) Geological Reform :— (12) The Origin of Species:—(13) Creticisms on the ‘* Origin of Species: —{14) On Descartes ‘* Discourse touching the Method of using One's Reason rightly and of seeking Scientific Truth.” The momentous influence exercised by Mr. Huxtey’s writings on physical, mental, and soctal science ts universally acknowledged : his works must be studied by all who would comprehend the various drifts of modern thought. ESSAYS SELECTED FROM LAY SERMONS, ADDRESSES, AND REVIEWS. Crown 8vo. Is. This volume includes Numbers 1, 3, 4, 7, 8, and 14, of the above. LESSONS IN ELEMENTARY PHYSIOLOGY. With numerous Illustrations. Sixth Edition. 18mo, cloth. 4s. 6d. This book describes and explains, in a series of graduated lessons, the principles of Human Physiology, or the Structure and Functions of the Human Body. The first lesson supplies a general view of the subject. This is followed by sections on the Vascular or Venous System, and the Circulation ; the Blood and the Lymph ; Respira- tion : Sources of Loss and of Gain to the Blood ; the Function of Alimentation ; Motion and Locomotion ; Sensations and Sensory Organs ; the Organ of Sight ; the Coalescence of Sensations with one another and with other States of Consciousness ; the Nervous System and Innervation ; Histology, or the Minute Structure of the Tissues. A Table of Anatomical and Physiological Constants is appended. The lessons are fully illustrated by numerous en- gravings. The new edition has been thoroughly revised, and a con- siderable number of new illustrations added: several of these have been taken from the Rabbit, the Sheep, the Dog, and the Frog, in order to aid those who attempt to make their knowledge real, by acquiring some practical acquaintance with the facts of Anatomy and Physi- ology. ‘* Pure gold throughout.” —Guardian. ‘‘ Unquestionably the clearest and most complete elementary treatise on this subject that we possess in any language.” —Westminster Review. 28 SCIENTIFIC CATALOGUE. Jellet (John H., B.D.)—A TREATISE ON THE THEORY OF FRICTION. By Joun H. Jexuet, B.D., Senior Fellow of Trinity College, Dublin; President of the Royal Trish Academy. 8vo. 85. 6d. The Theory of Friction, considered asa part of Rational Mechanics has not, the author thinks, received the attention which tt deserves: On this account many students have been probably led to regard the discussion of this force as scarcely belonging to Rational Mechanics at all; whereas the theory of friction is as truly a part of that subject as the theory of gravitation. The force with which this theory ws concerned is subject to laws as definite, and as fully susceptible of mathematical expression, as the force of gravity. This book is taken up with a special investigation of the laws of Sriction ; and some of the principles contained in it are believed to be here enunciated for the first time, The work consists of eight Chapters as follows :—I. Definitions and Principles. II. Equili- brium with Frictions, III. Extreme Positions of Equilibrium. LV. Movement of a Particle or System of Particles. WV. Motion ofa Solid Body. VI. Necessary and Possible Equilibrium. WII. Determination of the Actual Value of the Acting Force of Friction. VILL. Miscellaneous Problems—t. Problem of the Top. 2. Friction Wheels and Locomotives. 3. Questions for Exercise. ‘* The book supplies a want which has hitherto existed in the science of pure mechanics.” —Engineer, Kirchhoff (G.)—RESEARCHES ON THE SOLAR SPEC- “Lockyer (J. N.) TRUM, and the Spectra of the Chemical Elements. By. G. KircHHOFF, Professor of Physics in the University of Heidelberg. Second Part. Translated, with the Author’s Sanction, from the Transactions of the Berlin Academy for 1862, by Henry R. Roscog, B.A., Ph.D., F.R.S., Professor of Chemistry in Owens College, Manchester. Part II. 4to. 55. “Tt is to Kirchhoff we are indebted for by far the best and most accurate observations of these phenomena.” —Edin. Review. ‘* This memoir seems almost indispensable to every Spectrum observer.” —Phile= sophical Magazine. ELEMENTARY LESSONS IN AS- TRONOMY. With numerous Illustrations. By J. NoRMAN LocKYER, F.R.S, Ninth Thousand. r8mo- 5s. 6d. PHYSICAL SCIENCE, 29 The author has here aimed to give a connected view of the whole subject, and to supply facts, and ideas founded on the facts, to serve as a basis for subsequent study and discussion. The chapters treat of the Stars and Nebula ; the Sun; the Solar System ; Apparent Move- ments of the Heavenly Bodies ; the Measurement of Time; Light x the Telescope and Spectroscope; Apparent Places of the Heavenly Bodies ; the Real Distances and Dimensions ; Universal Gravitation. The most recent Astronomical Discoveries ave incorporated. Mr. Lockyer's work supplements that of the Astronomer Royal. ‘+ The book is full, clear, sound, and worthy of attention, not only as « popular exposition, but as a scientific ‘ Index.’ — Athenzeum.. “* The most fascinating of elementary books on the Sciences.” — Nonconformist. Macmillan (Rev. Hugh). For other Works by the same Author, see THEOLOGICAL CATALOGUE. HOLIDAYS ON HIGH LANDS; or, Rambles and Incidents in: search of Alpine Plants. Crown 8vo. cloth. Cs. The ain of this book is to impart a general idea of the origin, cha- racter, and distribution of those rare and beautiful Alpine plants which occur on the British hills, and which are found almost every- where on the lofty mountain chains of Europe, Asia, Africa, and America. In the first three chapters the peculiar vegetation of the Highland mountains is fully described ; while in the remaining chapters this vegetation is traced to its northern cradle in the moun- tains of Norway, and to its southern European termination in. the Alps of Switzerland. The information the author has to give is conveyed in a setting of personal adventure. ‘‘ One of the most’ charming. books of its kind ever written.” —Literary Churchman. “Mr. Ms glowing pictures of Scandinavian scenery.” —Saturday Review. FOOT-NOTES FROM THE PAGE OF NATURE. With: numerous Illustrations. Fcap. 8vo. 595. “ Those who have derived pleasure and profit from the study of flowers and ferns—suljects, it ts pleasing to find, now everywhere popular —by descending lower into the arcana of the vegetable kingdom, will find a still more interesting and delightful field of research in the objects brought under review in the following pages.” — Preface. “<< The naturalist and the botanist will delight in thie volume, and” 30 SCIENTIFIC CATALOGUE. those who understand little of the scientific parts of the work will linger over the mysterious page of nature here unfolded to their view.” —John Bull. Mansfield (C. B.)—A THEORY OF SALTS. A Treatise on the Constitution of Bipolar (two-membered) Chemical Com- pounds. By the late CHARLES BLACHFORD MANSFIELD. Crown 8vo. 145. “<< Mansfield,” says the editor, ‘‘ wrote this book to defend the prin- ciple that the fact of voltaic decomposition afforded the true indt- cation, if properly interpreted, of the nature of the saline structure, and of the atomicity of the elements that built it up. No chemist will peruse this book without feeling that he is in the presence of an original thinker, whose pages are continually suggestive, even though their general argument may not be entirely concurrent in direction with that of modern chemical thought.” Mivart (St. George).—ON THE GENESIS OF SPECIES. By St. GEorcE Mivart, F.R.S. Crown 8vo. Second Edition, to which notes have been added in reference and reply to Darwin’s ‘Descent of Man.” With numerous Illustrations. pp. xv. 296. 95. - The aim of the author is to support the doctrine that the various species have been evolved by ordinary natural laws (for the most part unknown) controlled by the subordinate action of ‘natural selection,” and at the same time to remind some that there ts and can be absolutely nothing in physical science which forbids them to regard those natural laws as acting with the Divine concurrence, and in obedience to a creative fiat originally imposed on the pri: i cosmos, ‘‘in the beginning,” by its Creator, its Upholder, and its Lord. Nearly fifty woodcuts ilustrate the letter-press, and a com- plete index makes all references extremely easy. Canon Kingsley, in his address to the ‘* Devonshive Association,” says, “Let me re- commend earnestly to you, as a specimen of what can be said on the other side, the ‘ Genesis of Species,’ by Mr. St. George Mivart, E.RS., @ book which Iam happy to say has been received elsewhere as tt has deserved, and, I trust, will be received so among you.” “In no work in the English language has this great controversy been treated at once with the same broad and vigorous grasp of facts, and the same liberal and candid temper.” —Saturday Review, | PHYSICAL SCIENCE. 31 Nature.—A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. Published every Thursday. Price 4¢. Monthly Parts, 1s. 4d, and 1s. 8¢.; Half-yearly Volumes, 10s. 6d. Cases for binding Vols. 1s. 6¢. “* Backed by many of the best names among English philosophers, and by a few equally valuable supporters in America and on the Conti- nent of Europe.” —Saturday Review. ‘‘ This able and well-edited Sournal, which posts up the science of the day prompily, and promises to be of signal service to students and savants.”—British Quarterly Review. Oliver.—Works by DaNnIEL OLIveER, F.R.S., F.LS., Professor of Botany in University College, London, and Keeper of the Herba- rium and Library of the Royal Gardens, Kew :— LESSONS IN ELEMENTARY BOTANY. With nearly Two Hundred Illustrations. Twelfth Thousand. 18mo cloth. 45. 6d. This book is designed to teach the elements of Botany on Professor Henslow’s plan of selected Types and by the use of Schedules. The earlier chapters, embracing the elements of Structural and Physio- logical Botany, introduce us to the methodical study of the Ordinal Types. The concluding chapters ave entitled, ‘‘ Howto Dry Plants” and “ How to Describe Plants.” A valuable-Glossary ts. appended to the volume. In the preparation of this work free use has been made of the manuscript materials of ‘the late Professor Henslow. FIRST BOOK OF INDIAN BOTANY. With numerous Illustrations. Extra fcap. 8vo. 6s. 6d. This manual is, in substance, the author's ‘* Lessons in Elementary Botany,” adapted for use in India. In preparing it he has had in view the want, often felt, of some handy résumé of Indian Botany, which might be serviceable not only to residents of India, but also to any one about to proceed thither, desirous of getting some pre- liminary idea of the botany of the country. It contains a well- digested s ry of all tial knowledge’ pertaining to Indian Botany, wrought out in accerdance with the best principles. of scientific arrangement.” —Allen’s Indian Mail. 32 SCIENTIFIC CATALOGUE. Penrose (F. C.)—ON A METHOD OF PREDICTING BY GRAPHICAL CONSTRUCTION, OCCULTATIONS OF STARS BY THE MOON, AND SOLAR ECLIPSES FOR ANY GIVEN PLACE. Together with more rigorous methods for the Accurate Calculation of Longitude. By F. C. PENROsE, F.R.A.S. With Charts, Tables, etc. 4to. 125. The author believes that if, by a graphic method, the prediction of occultations can be rendered more inviting, as well as more expedi- tious, than by the method of calculation, it may prove_acceptable to the nautical profession as well as to scientific travellers or amateurs, The author has endeavored to make the whole process as intelli- gible as possible, so that the beginner, instead of merely having to follow directions imperfectly understood, may readily comprehend the meaning of cach step, and be able to illustrate the practice by the theory. Besides all necessary charts and tables, the work contains a large number of skeleton forms for working out cases in practice. Roscoe.—Works by Henry E. Roscoz, F.R.S., Professor of Chemistry in Owens College, Manchester :— LESSONS IN ELEMENTARY CHEMISTRY, INORGANIC AND ORGANIC. With numerous Illustrations and Chromo- litho of the Solar Spectrum, and of the Alkalies and Alkaline Earths. New Edition. Thirty-first Thousand. 18mo. cloth. 4s. 6d. It has been the endeavour of the author to arrange the most important facts and principles of Modern Chemistry in a plain but concise and scientific form, suited to the present requirements of elementary instruction. For the purpose of facilitating the attainment of exactitude in the knowledge of the subject, a series of exercises and questions upon the lessons have been added. The metric system of weights and measures, and the centigrade therniometric scale, are used throughout this work. The new edition, besides new wood- cuts, contains many additions and improvements, and includes the most important of the latest discoveries. ‘‘We unhesitatingly pro- nounce it the best of all our elementary treatises on Chemistry.” — Medical Times, SPECTRUM ANALYSIS. Six Lectures, with Appendices, En- gravings, Maps, and Chromolithographs. Royal 8vo. 21s. PHYSICAL SCIENCE. 33 A Third Edition of these popular Lectures, containing all the most recent discoveries and several additional illustrations. “In six lectures he has given the history of the discovery and set Sorth the facts relating to the analysis of light in such a way that any reader of ordinary intelligence and information will be able to understand what ‘Spectrum Analysis’ is, and what are its claims to rank among the most signal triumphs of science.””—Nonconformist. “*The lectures themselves furnish a most admirable elementary treatise on the subject, whilst by the insertion in appendices to each lecture of extracts from the most important published memoirs, the author has rendered it equally valuable as a text- book for advanced students,” —Westminster Review. Roscoe and Jones.—THE OWENS COLLEGE JUNIOR COURSE OF PRACTICAL CHEMISTRY. By Professor RoscoE and FRANcIs JonESs, Chemical Master in the Grammar School, Manchester. 18mo. with Illustrations, 25. 6d. Stewart (B.) By BaLrour STEwart, F.R.S., Professor of Natural Philosophy in Owens College, Manchester. With numerous Illustrations and Chromolithos of the Spectra of the Sun, Stars, and Nebula. New Edition, 18mo. 45. 6d. A description, in an el tary , Of the most important of those laws which regulate the phenomena of nature. The active agents, heat,’ light, electricity, etc., are regarded as varieties of energy, and the work is so arranged that their relation to one another, looked at in this light, and the paramount importance of the laws of energy, are clearly brought out. The volume contains all the necessary illustrations. The Educational Times calls this “the acer ideal of a scientific text-book, clear, accurate, and thorough.” Thudichum and Dupré.—a TREATISE ON THE ORIGIN, NATURE, AND VARIETIES OF WINE. Being a Complete Manual of Viticulture and Génology. By. J. L. W. THupIcHUM, M.D., and AucusT Dupré, Ph.D., Lecturer on Chemistry at Westminster Hospital. Medium 8vo. cloth gilt. 255, In this elaborate work the subject of the manufacture of wine is treated scientifically in minute detail, from every point of view. A chapter is devoted to the Origin and Physiology of Vines, two to the Cc 34 Wallace (A. R.) SCIENTIFIC CATALOGUE, Principles of Viticulture; while other chapters treat of Vintage and Vinification, the Chemistry of Alcohol, the Acids, Ether, Sugars. and other matters occurring in wine. This introductory matter occupies the first nine chapters, the remaining seventeen chapters being occupied with w detailed account of the Viticulture and the Wines of the various countries of Europe, of the Atlantic Islands, ‘of Asia, of Africa, of America, and of Australia, Besides a number of Analytical and Statistical Tables, the work ts enriched with eighty-five illustrative woodcuts. ‘‘A treatise almost unique for its usefulness either to the wine-grower, the vendor, or the con- sumer of wine. The analyses of wine are the most complele we have yet seen, exhibiting at a glance the constituent principles of nearly all the wines known in this country.” —Wine Trade Review. CONTRIBUTIONS TO THE THEORY OF NATURAL SELECTION. A Series of Essays. By ALFRED RusseL WALLAeE, Author of ‘* The Malay-Archipelago,” etc. Second Edition, with Corrections and Additions. Crown ‘8vo. $s. 6d. (For other Works by-the same Author, see CaTa- LOGUE OF HisTORY AND TRAVELS.) Wr. Wallace has good clains to be considered as an tndependent originator of the theory of. natural selection. Dr. Hooker, in his address to the British Association, spoke thus of the author: “Of Mr. Wallace and his many contributions to philosophical biology it is not easy to speak without enthusiasm; for, putting ‘aside their great merits, he, throughout his writings, with a modesty as vare as I. believe it to be unconscious, forgets his own unquestioned claim to the honour of having originated indepen- dently of Mr. Darwin, the theories which he so ably defends.” The Saturday Review says: ‘‘He has combined an abundance of Sresh and original facts with a liveliness and sagacity of reasoning which are not often displayed so effectively on so small a scale.” The Essays in this volume are :—I. ‘‘On the Law which has regu- tated the introduction of New Species.” IT. ‘‘ On the Tendencies of Varieties to depart indefinitely from the Original Type.’ IIT, “‘Ali- mcry, and other Protective Resemblances among Animals.” I). ‘* The Malayan Papilionide, as ulustrative of the Theory of Natural Selection.” V. ‘On Instinct in Man and Ammals.” VI. “ The Philosophy of Birds Nests.’ VIE “A Theory of Birds’ Nests.” VILL, ‘* Creation by Law.” IX. ‘* The Develop- ment of Human Races under the Law of Natural Selection.” AL The Limits of Natural Selection as applied te Man.” PHYSICAL SCIENCE. : “35 Warington.—THE WEEK OF CREATION; OR, THE COSMOGONY OF GENESIS CONSIDERED IN ITS RELATION TO MODERN SCIENCE. By Grorcr War- inGTON, Author of ‘‘ The Historic Character of the Pentateuch Vindicated.” Crown 8vo. 45. 6d. The greater part of this work it taken up with the teaching of the Cosmagony. Its purpose is also investigated, and a chapter is devote? to the consideration of the passage in which the difficulties occur. ‘A very able vindication of the Mosaic Cosmogony, by a writer who unites the advantages of a critical knowledge of the Hebrew text and of distinguished scientific attainments.”— Spectator. Wilson.—Works by the late Groner Witson, M.D., F.R.S.E., Regius Professor of Technology in the University of Edinburgh :— RELIGIO CHEMICI. Witha Vignette beautifully engraved after a design by Sir Nor, PaTon. Crown 8vo. 85. 62. “George Wilson,” says the Preface to this volume, “‘had it in his heart jor many years to write a book corresponding to the Religio Medici of Sir Thomas Browne, with the title Religio Chemici. Several of the Essays in this volume were intended to form chapters of it. These fragments being in most cases like finished gems waiting to be set, some of them are now given in a collected form to his friends and the public. In living remembrance of his purpose, the name chosen by himself has been adopted, although the original design can be but very faintly represented.” The Contents of the volume avre:—‘ Chemistry and Natural Theology.” ‘‘ The Chemistry of the Stars; an Argument touching the Stars and their Inhabitants.” “< Chemical Final Causes; as illustrated by the presence of siti phorus, Nitrogen, and Iron in the Higher Sentient Organisms.’ “ Robert Boyle.” “Wollaston.” “‘Lifeand Discoveries of Dalton.” “« Thoughts on the Resurrection; an A ddress to Medical Students.” “<4 more Janey eduanl” the Spectator says, ‘has seldom fallen into our hands,” The Freeman says: ‘These papers are all valuable and deeply interesting. The production of a profound thinker, a suggestive and eloquent writer, and a man whose piety and genius went hand in hand.” C2 36 SCIENTIFIC CATALOGUE. Wilson—continued. THE PROGRESS OF THE TELEGRAPH. Fceap. 8vo. 1s. “While a complete view of the progress of the greatest of human inventions is obtained, all its suggestions are brought out with a rare thoughtfulness, a genial humour, and an exceeding beauty of utterance.” —Nonconformist. Winslow.—FORCE AND NATURE: ATTRACTION AND REPULSION. The Radical Principles of Energy graphically discussed in their Relations to Physical and Morphological De- velopment. By C. F. Winstow, M.D. 8vo. 14s. The author having for long investigated Nature in many directions, has ever felt unsatisfied with the physical foundations upon which some branches of science have been so long compelled to rest. Fhe question, he believes, must have oscurred to many astronomers and physicists whether some subtle principle antagonistic to attraction does not also exist as an all-pervading element in nature, and so operate as in some way to disturb the action of what is generally considered by the scientific world a unique force. The aim of the present work is to set forth this subject in its broadest aspects, and in such a manner as to invite thereto the attention of the learned. : The subjects of the eleven chapters are:—TI. ‘‘Space.” IT. ‘* Matter.” LIL, ‘* Inertia, Force, and Mind.” IV. ‘‘Molecules.” V. “ Molecular Force.” VI. ** Union and Inseparability of Matter and Force.” VIL. and VIII. ** Nature and Action of Force— Attraction—Repulsion.” IX. “‘Cosmical Repulsion. X. “\Me- chanical Force.” XT. ‘‘ Central Forces and Celestial Physics.” “Deserves thoughtful and conscientious study.”’—Saturday Review. Wurtz.—.\ HISTORY OF CHEMICAL THEORY, from the Age of Lavoisier down to the present time. By Ap. Wurtz. Translated by HENRY Wartrs, F.R.S. Crown 8vo. 6s. “« The discourse, as a résumé of chemical theory and research, unites singular luminousness and grasp. A few judicious notes are added by the translator.”—Pall Mall Gazette. ‘‘ Zhe treatment of the subject is admirable, and the translator has evidently done his duty most efficiently.” —Westminster Review. PHYSIOLOGY, ANATOMY, ETC. 37 WORKS IN PHYSIOLOGY, ANATOMY, AND MEDICAL WORKS GENERALLY. Allbutt (T. C.)—oN THE USE OF THE OPHTHALMO- SCOPE in Diseases of the Nervous System and of the Kidneys ; also in certain other General Disorders. By THoMAS CLIFFORD ALLBUTT, M.A., M.D. Cantab., Physician to the Leeds Genewl Infirmary, Lecturer on Practical Medicine, etc. etc. 8vo. 15s. The Ophthalmoscope has been found of the highest value in the inves : tigation of nervous diseases. But it is not easy for physicians who have left the schools, and are engaged in practice, to take up a new instrument which requires much skill in using ; it ts therefore Aoped that by such the present volume, containing the results of the author's extensive use of the instrument in diseases of the nervous system, will be found of high value ; and that to all students tt may prove a useful hand-book. After four introductory chapters on the history and value of the Ophthalmoscope, and the manner of investi- gating the states of the optic nerve and retina, the author treats of the various diseases with which optic changes are associated, and describes the way in which such associations take place. Besides the cases referred to throughout the volume, the Appendix con- tains details of 123 cases illustrative of the subjects discussed in the text, and a series of tabulated cases to show the Ophthalmoscopic : appearances of the eye in Insanity, Mania, Dementia, Melancholia and Monomania, Idiotcy, and General Paralysis. The volume is illustrated with two valuable coloured plates of morbid appearances of the eye under the Ophthalmoscope. ‘By its aid men will no longer be compelled to work for years in the dark ; they will have a definite standpoint whence to proceed on their course of investigation.” —Medical Times. THE EFFEC!YS OF OVERWORK AND STRAIN ON THE HEART AND GREAT BLOOD-VESSELS. (Reprinted from St. George’s Hospital Reports.) 25. 64. 38. SCIENTIFIC. CATALOGUE. Anderson.—ON THE TREATMENT OF DISEASES OF THE SKIN; with an Analysis of Eleven Thousand Consecutive Cases. By Dr. McCaLL ANDERSON, Professor of Practice of Medicine in Anderson’s University, Physician to the Dispensary for Skin Diseases, etc., Glasgow. Crown 8vo. cloth. 5s. The first part of this work, which it is believed will be found of the greatest value to ail medical men, as well as to all who are interested in its subject, consists of a carefully tabulated and critical analysis of 11,000 cases of skin disease, 1,000 of these having occurred in the author's private practice, and the rest in his hospital practice. These cases ave all classified under certain distinet heads, according to the nature and cause of the disease, while a number of the moré interesting cases are alluded to in detail. The second part of the work treats of the Therapeutics of Diseases of the Skin, and will be Sound to contain many valuable hints, the results of a long and cx- tensive experience, as to the most successful method of treating their multitudinous forms, , Anstie (F. E.)—NEURALGIA, AND DISEASES WHICH RESEMBLE IT, By Francis E. ANstir, M,D., M.R.C.P., Senior Assistant Physician to Westminster Hospital. Svo. 10s. 6d. ' Dr. Anstie is well known as one of the greatest living authorities on Neuralgia. The present treatise ts the result of many years careful independent scientific investigation into the nature and proper treat- ment of this most painful disease. The author has had abundant means of studying the subject bothin his own person and in the hundreds of patients that have resorted to him for treatment. He has gone into the whole subject indicated in the title ab initio, ana the publishers believe it will be found that he has presented it in an entirely original light, and done much to rob this excruciating and hitherto refractory disease of many of tts terrors. The Introduction treats briefly of Pain in General, and contains some striking and even original ideas as to its nature and in reference to sensation generally, t Barwell.—THE CAUSES AND TREATMENT OF LATERAL CURVATURE OF THE SPINE. Enlarged from Lectures published in the Zancet, By RicHarpD BaRWELL, F.R.C.S., Surgeon to and Lecturer on Anatomy at the Charing Cross Hospital. Second Edition. Crown 8vo. 45. 6a, \ PHYSIOLOGY, ANATOMY, ETC. 39. Having failed to find in books a satisfactory theory of those conditions which produce lateral curvature, Mr. Barwell resolved to investi- gate the subject for himself ab initio. The present work is the result of long and patient study of Spines, normal and. abnormal. fe believes the views which he has been led to form account for those essential characteristics which have hitherto been left unexplained ; and the treatment which he advocates is certainly less irksome, and will be found more efficacious than that which has hitherto been pursued. Indeed, the mode in which the first edition has been received by the profession.is a gratifying sign that Mr. Barwell’s principles have made their value and their weight felt. Many pages and-a number of woodcuts have been added to the Second Ldition. Corfield (Professor W. H.)—A DIGEST OF FACTS. RELATING TO THE TREATMENT AND UTILIZATION OF SEWAGE. By W. H. Corrietp, M.A., B.A., Professor of Hygiene and Public Health at University College, London. 8vo. 10s. 6d. Second Edition, corrected and enlarged. The author in the Second Edition has.revised and corrected the entjre work, and made many important additions, The headings of the eleven chapters are as follow:—I. ‘‘Early Systems: Midden-Heaps and Cesspools.” II. ‘Filth and Disease — Cause and Effect.’” IIT. “Improved Midden-Pits and Cesspools ; Midden- Closets, Pail- Closets, etc.” IV. ** The Dry-Closet Systems. V. ‘‘Water-Closets.’” VI. ‘* Sewerage.” VII. “Sanitary Aspects of the Water-Carrying System.” VIII. ‘Value of Sewage; Injury to Rivers.” IX. “Town Sewage; Attempts at Utilization.” X. “Filtration and Irrigation.” XT. ‘Influence of Sewage Farming on the Public Health.” An abridged account of the more recently published researches on the subject will be found in the Appendices, while the Summary contains a concise statement of the views which the author himself has been led to adopt: references have been inserted throughout to show from what sources the numerous quotations have: been derived; and an Index has been added. *‘ Mr. Corfield’s wark- is entitled to rank as a standard authority, no less than a con- ventent handbook, in all matters relating to sewage.” —Athenzum.. Elam (C.)—A PHYSICIAN’S PROBLEMS. By Cuaries ELAM, M.D., M.R.C.P. Crown 8yo, 9s. 40 _ SCIENTIFIC CATALOGUE. ConTENTS :—“‘ Natural Heritage.” ‘‘ On Degeneration in Man.” “On Moral and Criminal Epidemics.” ‘‘Body v. Mind.” *‘ I1- lusions and Hallucinations.” ‘On Somnambulism. ‘* Reverie and Abstraction.” Thesé Essays are intended as a contribution to the Natural History of those outlying regions of Thought and Action whose domain is the debateable ground of Brain, Nerve, and Mind. They are designed also to indicate the origin and mode of perpetuation of those varieties of organization, intelligence, and general tendencies towards vice or virtue, which seem to be so capriciously developed among mankind. They also point to causes for the infinitely varied forms of disorder of nerve and brain— organic and functional—far deeper and more recondite than those generally believed in. ‘* The book ts one which all statesmen, magistrates, clergymen, medical men, and parents should study and inwardly digest,” —Examiner. Fox.—Works by Witson Fox, M.D. Lond., F.R.C.P., Holme Professor of Clinical Medicine, University College, London, Physician Extraordinary to her Majesty the Queen, etc. :— DISEASES OF THE STOMACH: being a new and revised Edition of ‘‘THr DraGNosis AND TREATMENT OF THE VARIETIES OF Dyspepsia.” 8yo. 85. 6d. ON THE ARTIFICIAL PRODUCTION OF TUBERCLE IN ‘THE LOWER ANIMALS, With Coloured Plates. gto. 55. 6d. In this Lecture Dr. Fox describes in minute detail a large number of experiments made by him on guinea-pigs and rabbits for the pur- pose of inquiring into the origin of Tubercle by the agency of direct irritation or by septic matters. This method of inguiry he believes to be one of the most important advances which have been recently made in the pathology of the disease. The work is illustrated by three plates, each containing a number of carefully coloured illus- trations from nature. ON THE TREATMENT OF HYPERPYRENIA, as Illustrated in Acute Articular Rheumatism by means of the External Applica- tion of Cold. 8vo. 25. 6a, The object of this work is to show that the class of cases included under the title, and which have hitherto been invariably fatal, may, by a judicious use of the cold bath and without venesection, be brought PHYSIOLOGY, ANATOMY, ETC. 4l to a favourable termination. Minute details are given of the successful treatment by this method of two patients by the author, Sollowed by a Commentary on the cases, in which the merits of the mode of treatment are discussed and compared with those of methods followed by other eminent practitioners. Appended are tables of the observations made on the temperature during the treatment; a table showing the effect of the immersion of the patients in the baths em- ployed, in order to exhibit the rate at which the temperature was lowered in each case; a table of the chief details of twenty-two cases of this class recently published, and which are referred to in various parts of the Commentary. Two Charts are also introduced, . giving a connected view of the progress of the two successful cases, and a series of sphygmographic tracings of the pulses of the two patients. ‘*A clinical study of rare value. Should be read by everyone,”’—Medical Press and Circular. % Galton (D.)—AN ADDRESS ON THE GENERAL PRIN- CIPLES WHICH SHOULD BE OBSERVED IN THE CONSTRUCTION OF HOSPITALS. Delivered to the British Medical Association at Leeds, July 1869. By DoucLas GALTon, C.B., F.R.S. Crown 8vo. 3s. 6d. Ir this Address the author endeavours to enunciate what are those principles which seen to him to form the starting-point from which all architects should proceed in the construction of hospitals. Be- sides Mr. Galton’s paper the book contains the opinions expressed in the subsequent discussion by several eminent medical men, such as Dr. Kennedy, Sir James Y. Simpson, Dr. Hughes Bennet, and others. The work is illustrated by a number of plans, sections, and other cuts. ‘An admirable exposition of those conditions of struc- ture whith most conduce to cleanliness, economy, and convenience.” —Times. Harley (J.)—THE OLD VEGETABLE NEUROTICS, Hem- lock, Opium, Belladonna, and Henbane; their Physiological Action and Therapeutical Use, alone and in combination. Being the Gulstonian Lectures of 1868 extended, and including a Complete Examination of the Active Constituents of Opium. By JoHNn HARLEY, M.D, Lond., F.R.C.P., F.L.S., etc. 8vo. 125. The author's object throughout’ the investigations and experiments on which this volume is founded has been to ascertain, clearly and 42 SCIENTIFIC CATALOGUE. definitely, the action of the drugs employed on the healthy body in medicinal doses, from the smallest to the largest ; to deduce simple practical conclusions from the facts observed ; and then to, apply the drug to the relief of the particular conditions to which its action appeared suited. Many experiments have been made by the author both on men and the lower animals ; and the author's endeavour has been to present to the mind, as far as words may do, impres- sions of the actual condition of the individual subjected to the drug. ‘‘Those who are interested generally in the progress of medical science will find much to repay a careful perusal.” — Atheneum. Hood (Wharton).—ON BONE-SETTING (so called), "and its Relation to the Treatment of Joints Crippled by Injury, Rheu- matism, Inflammation, etc. etc. By WHARTON P. Hoop, M.D., M.R.C.S. Crown 8vo. 45. €d. The author fora period attended the London practice of the late Mr. Hutton, the famous and successful bone-setter, by whom he was initiated into the mystery of the art and practice. Thus the author is amply qualified to write on the subject from the practical point of view, while his professional education enables him to consider it in its scientific and surgical bearings. In the present work he gives a brief account of the salient features of a bone-setter’s method of pro- cedure in the treatment of damaged joints, of the results of that treat- ment, and of the class of casesin which he has seen tt prove successful. The author's aim is to give the rationale of the bone-setter’s practice, to reduce it to something like a scientific method, to show when force should be resorted to and when it should not, and to initiate surgeons into the secret of Mr. Hutton’s successful manipulation, Throughout the work u great number of authentic instances of successful treatment are given, with the details of the method of cure; and the Chapters on Manipulations and Affections of the Spine are illustrated by a number of appropriate and well-executed cuts. ‘* Dr. Hood's book is full of instruction, and, should be read by all surgeons.” —Medical Times. Humphry.—wWorks by G.M. Humrury, M.D., F.R.S., Professor of Anatomy in the University of Cambridge, and Honorary Fellow of Downing College :— . THE HUMAN SKELETON (including the Joints). With 260 Illustrations, drawn from nature. Medium 8vo. 28s. PHYSIOLOGY, ANATOMY, ETC. 43 Humphry (G. M »)—continued. Ln lecturing on the Skeleton it has been the author's practice, instead of giving a detailed account of the several parts, to request his students to get up the descriptive anatomy of certain bones, with the aid of some work on osteology. He afterwards.tested their acquire- ments by examination, endeavouring to supply deficiencies and correct errors, adding also such information—physical, physiologi- cal, pathological, and practical—as he had gathered from his own observation and researches, and which was likely to be useful and excite an interest in the subject, This additional informati forms, tn great part, the material of this volume, which is intended to be supplementary to existing works on anatomy. Considerable space has been devoted to the description of the joints, because it is _ less fully given in other works, and because an accurate knowledge of the structure and peculiar form of the joints is essential to a correct knowledge of their movements. The numerous illustrations were all drawn upon stone from nature; and in most instances, from specimens prepared for the purpose by the author himself. ‘* Bearing at once the stamp of the accomplished scholar, and evidences of the skilful anatomist. We express our admiration of the drawings.” —~~Medical Times and.Gazette. OBSERVATIONS IN MYOLOGY. 8vo. 6s. Professor Humphry’s previous works have gained for him avery high position as an original anatomist, and the present it is believed will fully sustain, that reputation, as well as prove valuable to al who take an interest in the higher problems of anatomy. The work includes the Myology of Cryptobranch, Lepidosiren, Dog-fish, Ceratodus, and Pséudopus Pallasii, with the Nerves of Cryptobranch and Lepidosiren and the Disposition of Muscles in Vertebrate Animals. The volume abounds in carefully executed illustrations. Huxley’s Physiology.—see p. 27, preceding. Journal of Anatomy and Physiology. Conducted by Professors HuMPHRY and NrwTon, and Mr. CLARK of Cambridge, Professor TURNER of Edinburgh, and Dr. Wricut of Dublin. Published twice a year. Old Series, Parts I. and IL., price 7s. 6. each. Vol. I. containing Parts I. and IL., Royal 8vo., 16s. New Series, Parts I. to IX. 6s, each, or yearly ‘Vols, 125. 6d. each. : Ad SCIENTIFIC CATALOGUE. Lankester.—COMPARATIVE LONGEVITY IN MAN AND THE LOWER ANIMALS. By E. Ray LANKESTER, B.A. Crown 8vo, 4s. 6d. ; This Essay gained the prize offered by the University of Oxford for the best Paper on the subject of which it treats. This interesting subject is here treated in a thorough manner, both scientifically and statistically. Maclaren.—TRAINING, IN THEORY AND PRACTICE. By ARCHIBALD MACLAREN, the Gymnasium, Oxford. 8vo. Handsomely bound in cloth, 7s. 6d. The ordinary agents of health are Exercise, Diet, Sleep, Air, Bath- ing, and Clothing. In this work the author examines each of these agents tn detail, and from two different points of view. First, as to the manner in which it is, or should be, administered under ordinary circumstances: and secondly, in what manner and to what extent this mode of administration ts, or should be, altered for purposes of training ; the object of ‘‘training,” according to the author, being “to put the body, with extreme and exceptional care, under the influence of all the agents which promote its health and strength, in order to enable it to meet extreme and exceptional de- mands upon its energies.” Appended are various diagrams and tables relating to boat-racing, and tables connected with diet and training. “ The philosophy of human health has seldom received 50 apt an exposition.”—Globe. ‘‘ After all the nonsense that has been written about training, it is a comfort to get hold of a thoroughly sensible book at last.””—John Bull. Macpherson.—Works by Joun MacpHerson, M.D. :— THE BATHS AND WELLS OF EUROPE; Their Action and Uses. With Hints on Change of Air and Diet Cures. Witha Map. Extra fcap. 8vo. 6s. 6d. This work ts tniended to supply information which will afford aid in the selection of such Spas as are suited for particular cases. Tt exhibits a sketch of the present condition of our knowledge on the subject of the operation of mineral waters, gathered from the wuthor’s personal observation, and from every other available source of information, ft is divided into four books, and each PHYSIOLOGY, ANATOMY, ETC. 45. ¥ Macpherson (J.)—continued. book into several chapters :—Book I. Elements of Treatment, iw which, among other matters, the external and internal uses of water are treated of. IT. Bathing, treating of the various kinds of baths. IT]. Wells, treating of the various kinds of mineral waters. LV. Diet Cures, in which various vegetable, milk, and other ““ cures” are discussed. Appended is an Index of Diseases noticed, and one of places named. Prefixed is a sketch map of the principal baths and places of health-resort in Europe. ‘‘Dr. Macpherson has given the kind of information which every medical practitioner ought to possess.” —The Lancet. ‘* Whoever wants to know the real character of any health-resort must read Dr. Macpherson’s book.” —Medical Times. OUR BATHS AND WELLS: The Mineral Waters of the British Islands, with a List of Sea-bathing Places. Extra feap.. 8vo. Pp- xv. 205, 35. 6d. . Dr. Macpherson has divided his work into five parts. He begins by a few introductory observations on bath life, its circumstances, uses, and pleasures; he then explains in detail the composition of the various mineral waters, and points out the special curative pro- perties of each class.