y i $f oi A re a e i , ---@---- =! i‘ B Ne ales : ai es: : cy ee ee ae ee ee ee ee ee are u 2 eg cl CORNELL UNIVERSITY LIBRARY FROM Le 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.B.SS. L.&E., F-LS., F.GS8., 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 Chis 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. Avr 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 80 75 70 65 60 55 50 45 40 35 50 25 wo ew Fey Oa NY WwW YO -i -2 —3 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. Allman, F.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. EDINBURGH, 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 ... ... ... ... ..., Page l 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: BR eee at aes ak oe SPage 142 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... ee, Page 197 AppeNDIx B.—Particulars of Depth, Temperature, and Position at the various Dredging-stations of H.M.S. ‘Porcupine’ in the Summer of TSAO wisn cin: saws Shot eee Gb days gS. sage ened. gee aes 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 Wh a 3 u i ° 62 A ° 61 a 60 B ql 59 | 796 *. 801 245 sop 178) sez a L 226 ow o 206 ase 08 679 ae an ; 220 268 # H 22 46 ____ 280 ce = oo o = 1 13 12° ik 10° 9 “ §. “ Lightning ”—1868. 160 —— 235 ° = 4 NIle1 0" Os = 3 6a SHH 234 188'92 6o 65 pee 182, 280 We 280 s == oof at Fh 32. 210 249 ee _ / 1 06 88 ae 83 SILETLAND I5| GB tao 122 ' vo £60 107 95 60 oF OF 78-59 8: va 2859 Bs 8 3s e 60 (20 7m "44 oz Pula & bs € 40 EES eee te 60 oe 48 af IW EN 44 a 4 ORKNEY 18 2 25 PD ° 3 cy Pentland Fath Aber ae 40 Af 6o ES FSET 38 NORTH SEA 30 at a ° zt ° 5 S ° CHAP, I1.] THE CRUISE OF THE ‘ LIGHTNING, 59 we were compelled to lie-to under canvas, drifting to the northward towards the edge of the Féroe Banks, any attempt to dredge being out of the question. On the 18th, during a lull, we sounded and found no bottom at 450 fathoms (Station 1, Pl. I.), with a minimum temperature of 9°5C., the temperature of the surface water being 12°5 C. This was so high a temperature for so considerable a depth that we sus- pected some error in the indications of the thermo- meters, three of Six’s registering instruments of the Hydrographic Office pattern. Subsequent observa- tions however in the same locality showed us that the temperature to the depth of 600 to 700 fathoms in that region is the moderate temperature of the northward current of the gulf stream. The Féroe Banks are greatly frequented in the fishing season by English and foreign fishing-smacks. Of course the principal object is to prepare cured or hard-fish, but many of the English vessels are welled for the supply of fresh cod for the London market. A large square tank occupies the middle of the vessel, and holes in the sides allow the water to pass freely through it. The water in the tank is thus kept perfectly fresh ; the best of the cod are put into it, and they stand the voyage perfectly. It is curious to see the great creatures moving gracefully about in the tank like gold-fish in a glass globe. They are no doubt ‘quite unaccustomed to man,’ and conse- quently they are tame; and with their long smooth mottled faces, their huge mouths, and lidless un- speculative eyes, they are about as unfamiliar objects as one can well see. They seem rather to like to be scratched, as they are greatly infested by caligi 60 THE DEPTHS OF 1HE SEA. [CHAP, 11, and all kinds of suctorial copepods. One of them will take a crab or a large fusus or buccinum quietly out of one’s hand, and with a slight movement transfer it down its capacious throat into its stomach, where it is very soon attacked and disintegrated by the power- ful gastric secretions, In one welled smack I visited on one occasion, one of the fish had met with some slight injury which spoiled its market, and it made several trips in the well between London and Féroe and became quite a pet. The sailors said it knew them. It was mixed up with a number of others in the tank when I was on board, and certainly it was always the first to come to the top for the chance of a crab or a bit of biscuit, and it rubbed its ‘ head and shoulders’ against my hand quite lovingly. On the 15th and 16th we dredged over the Féroe Banks at a depth of from 200 to 50 fathoms, the bottom gravel and nullipore, and the temperature from 8° to 10° C. The banks swarm with the com- mon brittle star Ophiothrix fragilis, with the Norway lobster Nephrops norvegicus, large spider crabs, several species of the genus Galathea, and many of the genus Crangon. So ample a supply of their favourite food readily accounts for the abundance and excellence of the cod and ling on the banks. There is some rough rocky ground on the Fxroe Banks, and notwithstanding all possible care and the use of Hodge’s ‘accumulators’ to ease the strain on the dredge ropes, we lost two of our best dredges and some hundreds of fathoms of rope. On the morning of the 17th we sighted Féroe, as usual only getting now and then a glimpse of the islands of this remote little archipelago by the lilting of the curtain of mist CHAP. IL] THE CRUISE OF THE ‘LIGHTNING. 61 which almost constantly envelopes them. Towards mid-day the weather improved a little, and as we threaded among the islands towards the little harbour of Thorshavn we greatly enjoyed our first view of their fantastic outlines, partly shrouded in their veil of mist; their soft green and brown colouring ren- dered still softer by the subdued sub-arctic light, and the streams and cascades embroidering the gentle slopes of the hills and falling over the cliffs like silver threads and tassels. The Féroe Islands are basaltic; terrace over terrace of soft easily decomposed anamesite probably of Miocene tertiary age. This uniform structure, and the absence of trees or any prominent form of vegetation, gives a singular sameness of effect. The scattered habitations are usually sad-coloured and roofed with growing turf, so that they are actually invisible at a little distance. We were greatly struck sometimes by the difficulty of estimating distance and height ; from the total want of familiar objects for comparison it was sometimes difficult to tell, passing among the islands and looking at them through the moist transparent air, whether the ridge was 500 feet high, or double or four times that height. The intermediate height is usually nearest the truth. Thorshavn, the capital of Féroe, is a strange little place. The land shelves down rather abruptly to a little bay, round the head of which the town is built ; and the habitations are perched among the rocks on such flat spaces as may be found for their reception. The result is irregular and picturesque; and very peculiar, for something like a scramble is necessary 62 THE DEPTHS OF THE SEA. [cHAP, 11, to get along some of the principal ‘streets.’ Above: the town a little clearing forms a miniature lawn and garden gay with bright flowers in front of the Governor’s house, a pretty wooden cottage residence like a villa in a suburb of one of the Scandinavian towns. Feroe, with its wet sunless climate and precarious crops of barley; its turf-thatched cottages and quiet little churches; its glorious cliffs and headlands and picturesque islets, the haunt of the eider-duck and the puffin; and its hardy, friendly islanders, with their quaint, simple, semi-Icelandic semi-Danish customs, has been described again and again. Fééroe only came to us as a pleasant haven of rest in the middle of our northern work. We paid it two visits of a week each in successive years, and one of the most pleasant memories in the minds of all of us connected with these expeditions will always be the cordial sympathy which we received from our friend M. Holten the Danish Governor, and his accomplished wife. M. Holten received us with the most friendly hospitality, and did everything in his power at all times to render us assistance and to further our views. He introduced us to the leading inhabitants of his dominion, and ' during the many pleasant evenings which we spent at his residence we heard all that we could of the economy of this simple little community, perhaps the most primitive and the most isolated in Europe. To Governor Holten I have already had the pleasure of dedicating a singularly beautiful sponge-form which we discovered during our return voyage; and to Madame Holten, to whose graceful pencil I am in- debted for the vignettes of Fsroe scenery which so CHAP, II] THE CRUISE OF THE ‘LIGHTNING, 63 _appropriately close these chapters, I now dedicate this volume, in remembrance of the great kindness which we invariably experienced from her and from her excellent husband. We lay in Thorshavn harbour till the 26th of August, the weather being so bad as to make all idea of pursuing our work outside hopeless. Whenever it was possible we dredged in the fiords with Froese boats and native boatmen, and we made the acquaint- ance of Sysselman Miller, the representative of Faroe in the Danish Parliament, who had made himself thoroughly conversant with the mollusca of Féroe, and had contributed his information to a list published in 1867 by Dr. O. A. L. Mérch. The shallow-water fauna seems to be scanty, as we find frequently to be the case on a bed of decomposing trap. It is of a character intermediate between that of Shetland and the Scandinavian coast. The forms which perhaps interested us most were Fusus despectus, L.—a hand- some shell which may possibly be only a very marked variety of Fusus antiquus, L.; but if so, it is one with very definite limit of distribution, as it occurs only rarely in very deep water in the British seas. In water of moderate depth among the Feroes it is abundant, apparently replacing F. antiquus. Another common Feroe shell is Tellina calcarea, CHEMNITZ,—a very abundant British glacial clay fossil, but not hitherto found recent in the British area. In the glacial clays near Rothesay it is in regular beds associated with Mya truncata, L, var. uddevallensis, ForBEs; Saxi- cava norvegica, SPRENGLER; Pecten islandicus, O. F. MUuuer, and other northern forms, and frequently so fresh that the two valves are still in position and 64 THE DEPTHS OF THE SEA. (CHAP. 11, held together by their connecting ligament. A some- what peculiar variety of Echinus sphera, O.F.MUutEr, was met with in one of the Fjords associated with a large form of Z. flemingii, BALL; and what appears to be a small form of Cucumaria, frondosa, GUNNER, was very common in shallow water on the tangles. While we were lying in Thorshavn harbour the Danish gunboat ‘Fylla’ and the French steam trans- port ‘L’Orient’ came in on their way from Iceland. Both of the vessels from the north had come through bad weather, and were glad to run into shelter. During the stay of the three war-ships the little capital was quite gay, and the Governor had abundant opportunity of exercising his genial hospitality. On the 26th of August, as the barometer rose a little and there seemed to be some slight sign of improvement, we left Thorshavn and steamed southward to dredge if possible in the deep channel between Féroe and Shet- land ; but the same evening wild weather set in again with a strong gale of wind from the north-westward, and the barometer down to 29:08. The hook and screw-jack fastenings of the main rigging went one after another, and we narrowly escaped losing the mast. The gale lasted till the 29th, when there was rather better weather; and after lying-to and drifting to the north-east for nearly three days, we took a sounding in lat. 60° 45’ N., long. 4° 49’ W. (Station 6). This gave a depth of 510 fathoms and a bottom tem- perature of 0°C. On the evening of the 29th and on the 30th the weather was sufficiently moderate to allow us to work our dredging gear, and the first trials were of great interest, as it was our first oppor- tunity of making the attempt in so great a depth of CHAP. I1.] THE CRUISE OF THE ‘ LIGHTNING, 65 water. The operation seemed however to present no. special difficulty, and nearly every haul was success- ful. The bottom was sand and gravel, mostly derived from the disintegration of the old rocks of the Scottish plateau. Animal life was not abundant, but several groups were fairly represented. Sandy rhizopods of a large size were numerous, and there were several con- spicuous crustaceans and echinoderms, among the latter an example of Astropecten tenuispinus, of a briftiant scarlet colour, which came up entangled on the line. On the 31st bad weather set in again, and we could neither sound nor dredge. On the Ist of September we got one temperature sounding in 550 fathoms with —1°2 C., but could do no work. The next day, September 2, was more moderate, and we dredged all day at a depth of only 170 fathoms over a very restricted shoal, which, singularly enough, we could not find when we sought for it the year after in the ‘Porcupine. Here we found animal life abundant and varied—a mixture of celtic and scandinavian forms. The bottom was chiefly small rounded pebbles of the dark anamesite of the Féroes, and sticking to them, singly or in little groups like plums on their stems, were many large specimens of the rare brachiopod Yerebratula cranium, O. F. M@er, along with abundance of the commoner form Terebratulina caput-serpentis, L. ; The following day, September 3, we were again in deep water, about 500 fathoms, with a bottom tem- perature a little below the freezing-point, the thermo- meter at the surface giving 10°5 C. Here we took representatives of many invertebrate groups—rhizo- pods, sponges, echinoderms, crustaceans, and molluscs; F 66 THE DEPTHS OF THE SEA. {cHar. u. among them a magnificent specimen of a new star- fish which has been since described by M. G. O. Sars under the name of Brisinga coronata (Fig. 5). The genus Brisinga was discovered in 1853 by M. P. Chr. Absjérnsen, who then dredged several specimens of another species, B. endecacnemos, Axss., at a depth of 100 to 200 fathoms in the Hardangerfjord on the Norway coast a little to the south of Bergen. These are certainly very wonderful creatures. At first sight they look intermediate between ophiurids and star-fishes, the arms too thick and soft for the former, but much more long and delicate than we usually find them in the latter group. The disk is small, about 20 to 25 mm. in diameter ; in B. endecacnemos nearly smooth, in B. coronata covered with spines. The madreporiform tubercle is on the dorsal surface close to the edge of the disk. A: firm ring of calcareous ossicles forms and supports the edge of the disk, and gives attachment to the arms. The arms are ten or eleven in number: the latter number is probably abnormal. They are sometimes as much as 30 centimetres in length; narrow at the base, where they are inserted into the ring ; enlarging considerably towards the middle, where the ovaries are developed; and tapering again to the end. Rows of long spines border the ambulacral grooves ; the spines are covered with a soft skin, which, when the animal is quite fresh, forms a little transparent, sack-like expan- sion full of fluid at the end of each spine. The soft covering of the spines is full of small pedicellariz, and pedicellariz: are likewise scattered in groups over the surface of the arms and disk. The arms in B. endecacnemos are nearly smooth, CHAP. I1.] THE CRUISE OF THE ‘ LIGHTNING, 67 , Fic. 5.—Brisinga coronata, GO. Sans. Natural size. (No. 7.) F 2 68 THE DEPTHS OF THE SEA. [cHAP, 11, ribbed transversely here and there by slightly raised calcareous bands passing irregularly partly or wholly across them. In B. coronata these ridges are sur- mounted by crests of spines. Both species are of a rich crimson colour, passing into orange-scarlet. The arms are easily detached from the disk. We never got one of either species nearly entire, but even coming up in pieces they were certainly the most striking objects we met with. One was sufficient to give a glorious dash of colour to a whole dredgeful. “Le nom Brisinga est dérivé d’un bijou brillant (Brising) de la déesse Freya,” which brings a pleasant flavour of Scandinavian heathendom about it. “J’ai trouvé cette Astérie brillante & Hardangerfjord a l'aide du dredge & la fin du mois d’aott 1858, a la profon- deur de 100 & 200 brasses, ot elle était placée sur le plan latéral et perpendiculaire d’une montagne, qui semblait descendre de 80 & 90 brasses jusqu’a 200 brasses et méme de plus. Elle se trouve bien rare- ment; en draguant plus de huit jours avec beaucoup d’assiduité dans la méme localité et dans les environs je trouvais seulement quelques bras, et quelques indi- vidus plus ou moins grands, dont le plus petit entre les pointes des bras opposés avait une grandeur de 6 pouces, le plus grand environ 2 pieds de diamétre. Aucun deux n’était sans étre endommagé; l’animal est extrémement fragile et semble, comme les coma- tules et quelques espéces d’Ophiolepis et d’Ophiotrix, a cause de la pression diminuante de l’eau, tiré vers la surface, par un effort vigoureux, se défaire de ces bras, qui toujours se détachent & l’endroit ot ils sont unis avec l’anneau du disque. Le surpois du bras en comparaison du disque trés petit, et la grandeur con- CHAP. I1.] THE CRUISE OF THE ‘ LIGHTNING, 69 sidérable de ’animal, augmente aussi les difficultés & le faire sortir du dredge sans étre déchiré. Quoique je fusse assez heureux pour le saisir avant qu’il sortait de leau, et malgré toute la précaution possible, je réussis seulement a conserver deux disques d’une paire de bras fermes, mais & ceux-ci méme le peau était rompue. Quand l’animal est complet et cohérent, ainsi que je lai vu une ou deux fois sous eau dans le dredge, il est véritablement un exemplaire de luxe, une ‘ gloria maris.’ ’’? The bad weather was unrelenting, and again inter- rupted us for a couple of days: we got a sounding however on the 5th of September, in lat. 60° 30’ N. and long. 7° 16’ W., with no bottom at 450 fathoms and a minimum temperature about the freezing-point. It will be seen by the chart that the last five stations, Nos. 7 to 11, form an oblique line from south-east to north-west between the northern part of Orkney and the Féroe Bank. The bottom is throughout a mixture of gravel and sand, with patches of mud; Nos. 7 and 8 principally the débris of the metamorphic rocks of the north of Scotland; Nos. 9, 10, and 11 chiefly volcanic, the detritus of the Féroe traps. This line of soundings is entirely within what we afterwards learned to call the ‘co!d area,’ the thermometer for depths below 300 fathoms indicating a temperature slightly above or below 0° C. As we were now again approaching the Féroe fishing-banks, we shaped our course southwards, and on the morning of September 6th we sounded and 1 Description d’un Nouveau Genre des Astéries, par P. Chr. Abs- jornsen, in “ Fauna littoralis Norvegie,” by Dr. M. Sars, J. Koren, and D. C. Danielssen, Seconde Livraison. Bergen, 1856, p. 96. 70 THE DEPTHS OF THE SEA. [cHap, 11, dredged in lat. 59° 36’, long. 7° 20’ (Station 12), with a depth of 530 fathoms and a ‘warm area’ temperature of 6°40. The dredging here was most interesting. The bottom was for the first time ‘Atlantic ooze,’ a fine bluish-grey tenacious calcareous mud, with some sand and a considerable admixture of Globigerine. Tmbedded in this mud there came up an extraordinary number of silicious sponges of most remarkable and novel forms. Most of these belonged to an order which had been described by the writer’a couple of years before as * Porifera vitrea,’ a tribe at that time but little known, but which have since become very familiar to us as denizens of the abyssal zone. Working from more extended data, Professor Oscar Schmidt afterwards defined the group more exactly as a family, under the name of Hexactinellide—the term which I shall here adopt. The relations and peculiarities of this singular group will be fully discussed in a future chapter. The most characteristic forms which we met with on this occasion were the beautiful sea-nests of the Setubal shark-fishers, Holtenia carpenteri, Wy. T. (Fig. 6), and the even more strange Hyalonema lusitanicum, BARBOZA DE BocaGeE, closely related to the glass-rcpe sponges of Japan which have so long perplexed naturalists to determine their position in the animal series, and their relation to their constant companion the parasitic Palythoa. Holtenia carpenteri is an oval or sphere 90 to 100 mm. in height, with one large oscular opening at the top about 30 mm. in diameter, whence a simple cylindrical cavity cupped at the bottom passes down vertically into the substance of the sponge to the CHAP. II] THE CRUISE OF THE ‘ LIGHTNING, 71 depth of 55 mm. The outer wall of the sponge SS eer = PACA ee Fic. 6.—Holtenia carpenteri, WxvILLE THomson. Half the natural size. (No. 12.) consists of a complicated network of the cross-like 72 THE DEPTHS OF THE SE. [orap. 11, heads of five-rayed spicules. One ray of each spicule dips directly into the body of the sponge, and the other four, which are at right angles to it, form a cross on the surface, giving it a beautiful stellate appearance. The silicious rays of one star curve towards and meet the rays of the neighbouring stars, and run parallel with them. All the rays of all the spicules are thickly invested with consistent semi-transparent gelatinous matter, which binds their concurrent branches together by an elastic union, and fills up the angles of the meshes with softly curved viscous masses. This arrangement of the spicules, free and yet adhering together by long elastic connections, produces a strong, flexible, and very extensible tissue. The cylindrical oscular cavity within the sponge is lined with nearly the same kind of network. ‘When the sponge is living, the interstices of the silicious network are filled up both outside and in with a delicate fenestrated membrane formed of a glairy substance like white of egg, which is constantly moving, extending or contracting the fenestra, and gliding over the surface of the spicules. This ‘sarcode,’ which is the living flesh of the sponge, contains distributed through it an infinite number of very minute spicules, presenting the most sin- gular and elegant forms very characteristic of each species of sponge. A constant current of water carried along by the action of cilia passes in by apertures in the outer wall, courses through the passages in the loose texture of the intermediate sponge-substance carrying organic matter in solution and particles of nourishment into all its interstices, CHAP. I1.] THE CRUISE OF THE ‘LIGHTNING’ 73 and finally passes out by the large ‘osculum’ at the top. Over the upper third of the sponge a multitude of radiating rigid silicious spicules form a kind of ornamental frill, and from the lower third a perfect maze of delicate glassy filaments, like fine white hair, spread out in all directions, penetrating the semi-fluid mud, and supporting the sponge in its precarious bed by increasing its surface indefinitely while adding but little to its weight. This is only one of the ways by which sponges anchor themselves in the ooze of the deep sea. Hyalonema sends right down through the soft mud a coiled whisp of strong spicules, each as thick as a knitting needle, which open out into a brush as the bed gets firmer, and fix the sponge in its place somewhat on the principle of a screw pile. 9 IRELAND Cork v rateniiag ae ie, ” Lon\don ot é BRISTOL CHANNEL D i : C cle so x av AN Dover es eS Portsmouth S ( 7 ye 7 A 5 Setlly Te Ww as axe i es sae t $ & yxo® GuernseyPeo — ° Rous ‘ Se erseyS fs ™ we | ptt taeeea 4 4 o ° oD or : is BISCAY Hy a 4 4 i H H # 4 i f ‘ & ‘ ; | ce Vigo ° i 2 Oporto = ; Madrid ao ‘pia €.Carvoeiro \ | ‘2 c+ Lésbon |. Re : pL CEspichetl C.S Vinee Cibralta? Strait 31¢ 110 SS 283" Jace BELGIUM Str, SE pntfs o Se, woetb 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 FE. 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. Matmeoren, 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? 1838 considerable success at depths from 380 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 | Orders. | eae Recent. Fossil. neti | Brachiopoda. . . . 1 1 — = Conchifera | 50 32 1 17 Solenoconchia . 7 3 — 4 Gasteropoda . 113 42 23 48 Heteropoda . 1 1 — _— Pteropoda . 5 14 12 — 2g S eens L | 186 91 24 i 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 paptillosa, 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, Toretlia 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 THomsoyn. 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 axisis 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 AAs e oth te te, BBG 10 fathoms . . Sy . 20°9 20, ee -_ . 16 30, . . : we J Aa 40, ee a D6 4 50 =, Bose ah, oe oaarne oe . « 16 100, i a See 2 es Tes 586, fen Agate. oop Ot 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 i in Tempera- Tempera- Position. Station. | Pathoms. ture. ture. 41 730 | 18° 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 '.30" 44 455 | 13-0 21-0 35 42 20” 8 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 10 380” At this last Station (No. 47) a serial sounding was taken, which entirely confirmed the results of the first (No. 40) :— Surface. . . . ...... . 20°°-96, 10 fathoms . . . . . . . (158 20 ~—C«« Ss ila te op al ag oe be B30. 8 2, mod edinde oh -. Boe LEMS 40, : OU oe Boy oe EBS 3 50, ae? obese ey Le, 100 _—_,, a. hed fe oS » 12°6 845, , he Gh 12.56 192 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 : Nucula quadrata, n.sp.; NV. pumila, ABSJORNSEN ; Leda, n. sp.; Verti- cordia granulata, Sec.; Hela tenella, JEFFREYS; Trochus gemmulatus, Pu.; Rissoa subsoluta, ARADAS ; Natica affinis, Guetin; Trophon 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 cnar.iv.] T/7E CRUISES OF THE ‘ PORCUPINE.’ 198 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, Broccar (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 Oo 194 THE DEPTHS OF THE SE4. [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 nehinvidea. 4. 4 2 4 2 3D Holothuridea . . . ... 8 — 36 Gephyrea . . eg. $6 Vermes . : te eee es . ol — 57 Polyzoa. . . . pS ARS a 35 Tunieata e208 ow kg a Mollusca . . . . Brachiopoda ok ee Cae BE, eo | Conchifera. . . . . 2. . BY { Cephalophora. . . « @ 108 — 133 Arachnida , ; 1 SEED hrs: 3 Vee bh Mahl fae . . 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. [cHar. 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 cuar. 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 B. 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. Nature, 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—ith 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. Ceecum trachea 2 Pe nae or strangu- Several. 2 With a notched ” ” ” ” ” . apex. Corbula nucleus Several. Nera cuspidata . whe 1 and valves. » costulata 1 2 and valves. Pandora obtusa 2 Psammobia ferroensis Valves. Tellina distorta a 1 and valves. » balaustina. 3 » Serrata. 1 and valves. » depressa | 1 valve. Syndosmya tenuis! (prismatica!) i ca Valves. Venus ovata ‘ 2p oe 1 Valves. 282 THE DEPTHS OF THE SEA. [cHar. v1, Species obtained. oe oe ae Observations. Suleated to the Astarte incrassata? 8 margin, some of them radiated. Cardium papillosum . 1 dy minimum 1 levigatum . Bia Valve. Cardita squamosa . 5 Lucina spinifera : 5 Diplodonta rotundata ans 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 . ao Valves. «testa. 8 1 » similis Valves. » sulcatus m4 land ? valves. Anomia patelliformis af 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 Tperfect. 35 elegantissima, 4 es indistincta (2) . 2 ” ” 3 Eulimella acicula . cae 1 Trochus tenuis, or dubius . “is 1 » Magus. . .. Several. » montagui 1 CHAP. VI.] DEEP.SEA DREDGING. 283 Species obtained. ae py BS Observations. Trochus montagui Several. ‘3 * ax Several. Turritella terebra. . Few. Small. % tricostalis . 1 Cerithum vulgatum, var. 1 7 retrenlatum Several. ; « a) nh 2 White. Fusus muricatus . 1 . 7 1 The . apesles at _ ibraltar. Pleurotoma nanum 1 i secalinum 1 Murex tetrapterus é sa 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 3 clandestina . Several. Several. Cyprea pulex . 8 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.8. ‘ Porcupine’ in the year 1869, ete. Appendix A.—Surface Temperatures observed on board H.M.S. ‘Porcupine’ during the Summers of 1869 and 1870. AppenDIx 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. Appendix 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.ML.S. ‘ 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 S8ix’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. 239 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.] 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 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, vu 2 292 THE DEPTHS OF THE SEA. (cHar. vu. 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 ea 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 Fahrenheit degrees; the large bulb is enclosed in an outer shell three- fourths filled with alcohol and her- metically sealed. It is right to mention that I am informed by , Sir Edward Sabine that the ther- “wrotecting "the “Miler. MOmeters used by Sir John Ross Casellathermometer. The , ends of theeaseaboveand in his Arctic voyage in 1818 were sm ste 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- SE ki i i aul CHAP. VIL] DEEP-SEA TEMPERATURES. 993 ment. A modification of Phillip’s maximum ther- mometer devised by Sir William Thomson, in which the thermometer is entirely encased in an outer shell of glass partly filled with alcohol, appears to have the smallest error of all. A neat modification of Breguet’s metallic ther- mometer was designed by Joseph Saxton, Esq., of the U.S. Office of Weights and Measures, for the use of the U.S. Coast Survey. A riband of platinum and one of silver are soldered with silver solder to an intermediate plate of gold, and the compound riband is coiled round a central axis of brass, with the silver within. Silver is the most expansible of the metals under the influence of heat, and platinum nearly the least. Gold holds an intermediate place, and its intervention between the platinum and silver moderates the strain, and pre- vents the coil from cracking. The lower end of the coil is fixed to the brazen axis, while the upper 1 In Messrs. Negretti and Zambra’s list of. meteorological instruments published in 1864, a deep-sea thermometer on this plan is mentioned (p. 90): “The thermometers constructed for this purpose do not differ materially from those usually made under the denomination of Six’s thermometers, except in the following most important particulars :— The usual Six’s thermometers have a central reservoir or cylinder containing alcohol; this reservoir, which is the only portion of the instrument likely to be affected by pressure, has been, in Negretti and Zambra’s new instrument, superseded by a strong outer cylinder of glass, containing mercury and rarefied air. By this means the portion of the instrument susceptible of compression has been so strengthened, that no amount of pressure can possibly make the instrument vary.” Some obscurity is introduced into this passage by the use of the word “superseded ;’ but I am assured by Messrs. Negretti and Zambra that in principle this instrument was exactly the same as that devised by Professor Miller and constructed by Mr. Casella. 294 THE DEPTHS OF THE SEd. (cHar. vil. ae end is attached to the base of a short cylinder. Any variation of temperature causes the coil to wind or unwind, and its motion acts to rotate the axial stem. This motion is magnified by multiply- ing wheels, and is registered upon the dial of the instrument by an index which pushes before it a registering hand, moving with sufficient friction merely to retain its place when thrust forward by the index hand of the thermometer. The instru- ment is graduated by trial. The brass and silver portions are thickly gilt by the electrotype process to prevent the action of sea-water upon them. The box which covers the coil and indicatory part of the thermometer is merely to protect it from accidental injury, and is open so as to permit the free passage of the sea-water. This instrument appears to answer tolerably well for moderate depths, its error up to 600 fathoms not greatly exceeding 0°5C.; at 1,500 fathoms, however, the error rises to 5°C., quite as creat as that of the unprotected Six’s thermometers, and the error is not so constant. It is evident that under great pressure little confidence can be placed upon instruments which give their indica- tions through metal machinery. Before H.M.S. ‘ Porcupine’ started on her summer cruise in 1869, a valuable series of experiments were made upon the effect of pressure on various register- ing thermometers at Woolwich, under the superin- tendence of the Hydrographer and of the Deep-Sea Committee of the Royal Society. The object was to subject all the forms of deep-sea thermometers in use to pressures in a hydraulic press, equivalent to the pressures which they would encounter at different cuap. vit] DEEP-SEA TEMPERATURES. 295 depths in the ocean, to determine the amount and sources of error, to ascertain which was the most satisfactory instrument, and if possible to construct a scale by which the observations hitherto taken with ordinary instruments might be roughly cor- rected, so as to be made available. As there was some difficulty in getting the use of a suitable press, Mr. Casella undertook to have a testing apparatus constructed at his own place in Hatton Garden, capable of producing a pressure of three tons on the square inch. The results were very interesting.’ The first expe- riment went to test the value of the various instru- ments. A Miller-Casella thermometer was placed in the cylinder with No. 57, a good thermometer by Casella, of the ordinary Hydrographic Office pattern, and they were subjected together to a pressure of 4,032 lbs., equal to 1,480 fathoms, with the following result :— Minimum, 7 Maximum. Ther + Difference of 7 Maximum. Before. After. Before. After. 2 8 6C. | 8° 6C. | 8° 6G. | 8°85 C) 0 250. 57 8:6 8°6 8:6 12° 75 4:15 That is to say, the temperature remaining the same, the pressure forced up No. 57 to 12°75 C., and left its index there, 1 On Deep Sea Thermometers, by Captain J. E. Davis, R.N. Nature, vol. iii. p. 124. Abridged from a Paper read before the Meteorolo- gical Society, April 19th, 1871. 296 THE DEPTHS OF THE SEA. [CHAP. VII. This experiment at once proved the advantage of the encased bulb. It was repeated with other ther- mometers with the same pressure and for the same period of time, and it was found that while the mean difference of the encased bulbs was only 0°95, that of the ordinary deep-sea thermometers was, as in No. 57, 7°25. It follows, also, from these experiments, that very nearly all the difference or error is due to pres- sure on the full bulb, and that by encasing that bulb we have a nearly perfect instrument. The next series of experiments was made to esta- blish a scale by which observations by the ordinary instruments might be approximately corrected for pressure. The following table gives the errors of six thermometers at different pressures. The ‘standard’ is an encased Miller-Casella, the last a registering minimum thermometer by Casella enclosed in a hermeticaliy sealed glass tube on Sir William Thomson’s plan. Pressure in Standard. No, 54. No. 56. No. 76. No. 73. Thomson. Fathoms, | I : : : : 950 | 07 4. 500 750 1,000 1,250 1,500 1,750 2,000 2,250 2,500 a oH oO Her OCOCOCS DEH OMDOWR MAOTE RWW NH O DLW AHweonwnoa AATE Rw Ne AION OWNONW WMS — AOI Rwwmwmrec NMOwrTS8OMANwWRA TAMOTOIPAPNWWH OS O OB AI Oo a O01 SeocoooosoSg WR wWIDwWOWoOSO a ci... ... 2 eo : - The mean difference for each 250 fathoms in each thermometer is as follows :-— CHAP, VII. ] DEEP-SEA TEMPERATURES. 297 \ Thermonieter. Difference. | | Standard . + 0°120C, b4 . + 0°72 56. + 0°67 76. + 0°65 1d. 3. 4 + 0°76 Thomson . + 0°03 | During these experiments the water in the cylin- der was of course maintained as far as possible at the same—or at a known temperature; a certain amount of calorific effect must, however, be pro- duced by the sudden compression of the water, and the next series of experiments was performed in order to determine the amount of that effect. Three of Phillips’s encased maximum thermometers (Sir William Thomson’s design), being entirely protected from any effect from compression, were employed for this purpose, with the following result :— Pressure, 6,817 lbs. = 2,500 fathoms. Thermometer. Difference. 11,424 . + 0°05 C. 9,649 . + 0°22 9,645 . + 0°11 So that this source of error is absolutely trifling. The true error of the Miller-Casella thermometer, as deduced from these observations, is— For 250 fathoms 0°:079 C. For 2,500 fathoms 0°79 C, 298 THE DEPTHS OF THE SEA. [cHAP. VII. This, therefore, may be regarded as a perfect instru- ment for all ordinary purposes. A number of the instruments which had been previously tested in the press were sent out in the ‘Porcupine’ on her summer cruise in 1869, and on her return the results of Captain Calver’s observa- tions at different depths in the ocean were carefully compared with the effects of equivalent pressures ap- plied to the thermometers in Mr. Casella’s ‘ Bramah’s press.’ The result in the ocean, contrary to that in the hydraulic press, proves that the elasticity is not regular or in a ratio to the pressure, but that after continuing regular up to a pressure of 1,000 fathoms, it decreases in a compound ratio to a pressure of 2,000 fathoms, when its elasticity nearly ceases. The following table gives an abstract of the behaviour of Casella’s ordinary Hydrographic Office thermometers in the ocean and in the press :— ERROR. PER 250 Fatuoms. Pressure. Press. Ocean. Press. Ocean. Fathoms. 250 0°: 726 C. 0° 738 C. 0° 726C. 0°: 738 C. 500 1: 548 1+ 564 0: 774 0-782 750 2° 123 2° 223 0° 708 0° 741 1,000 2° 474 3° 015 0: 674 0° 754 1,250 3° 255 3° 492 0: 651 0 + 698 1,500 4°107 3° 921 0: 684 0° 653 1,750 4° 555 4° 056 0+ 650 0° 579 2,000 5° 354, 4° 284 0: 669 0: 536 2,250 6° 021 — 0: 669 —_ 2,500 6° 817 —_ 0+ 682 —_ For taking bottom temperatures at great depths two or more of the Miller-Casella thermometers are CHAP. VII] DEEP-SEA TEMPERATURES. 299 lashed to the sounding-line at a little distance from one another, a few feet above the attaching ring of a ‘detaching’ sounding instrument. The lead is run down rapidly, and, after the weight has been disengaged by contact with the ground, an interval of five or ten minutes is allowed to elapse before hauling in. The shorter of these periods seems to be quite sufficient to insure the instrument acquiring the true temperature. In taking serial temperature soundings—that is to say, in determining the tem- perature at certain intervals of depth in deep water —the thermometers are attached above an ordinary deep-sea lead, the required quantity of line for each observation of the series run out, and the ther- mometers and lead are hove in each time. This is a very tedious process; one serial sounding in the Bay of Biscay, where the depth was 850 fathoms and the temperature was taken at every fifty fathoms, occupied a whole day. I ought to mention that in taking the bottom temperature with the Six’s thermometer the instru- ment simply indicates the lowest temperature to which it has been subjected; so that if the bottom water were warmer than any other stratum through which the thermometer had passed, the observation would be erroneous. This is only to be tested by serial soundings, but in every locality where the temperature was observed during the ‘Porcupine’ expeditions the temperature gradually sank, some- times very steadily, sometimes irregularly, from the surface to the bottom, the bottom water having been constantly the coldest. It is probable that under certain conditions in the Polar seas, where the sur- 300 THE DEPTHS OF THE SEA. [cHap. vil. face is sometimes subjected to intense cold, warmer water may be found below, until the balance is. restored by convection. This I believe, however, to be entirely exceptional; and it may certainly be taken as the rule for all latitudes that if we dis- regard the film which is affected by diurnal altera- tions, the temperature sinks from the surface to the bottom. The first important series of deep-water tempera- ture observations was made during the Arctic voyage under Sir John Ross in the year 1818. On Sept. the Ist, lat. 73° 37’ N., long. 77° 25’ W., the temperature at the surface being 1°3 C., the registering thermo- meter gave at eighty fathoms 0°C., and at 250 fathoms —1"4 C. On the 6th of September, lat. 72° 23’ N., long. 73° 07’ W., the first serial sounding on record was taken, the thermometer having been let down to 500, 600, 700, 800, and 1,000 fathoms in succession, the thermometer showing each time a lower temperature and indicating at the greatest depth named a temperature of —3°6 C. On the 19th of September, in lat. 66° 50’ N., long. 60° 30’ W., another serial sounding was taken, the tempera- ture being registered at 100 fathoms —0°9 C., at 200 —1°-7 C., at 400 —2°-2 C., and at 660 fathoms —3°6 C. On the 4th of October, lat. 61° 41’ N., long. 62° 16’ W., Sir John Ross sounded, but found no ground in 950 fathoms; at the same time the self-registering thermometer was sent down, and the temperature of the sea at that depth. was found to be 2° C., while at the surface it was 4° C., and the air at 2°77 C. I am informed by General Sir Edward Sabine, who accompanied Sir John Ross’s expedition, CHAP, VII.] DEEP-SEA TEMPERATURES. 301 that these observations were made with registering thermometers guarded somewhat in the same way as those which we employed in the ‘ Porcupine.’ There is almost sufficient internal evidence that the mode of protecting these thermometers must have been satisfactory, for the temperatures at the greatest depths are such as might have been expected from Miller-Casella thermometers. Unguarded instru- ments would certainly have given higher indica- tions. The last of the observations quoted, a considerable way up Davis’ Strait, is of great interest. The tem- perature of the surface of the sea was nearly a degree and a half Centigrade above that of the air, and the temperature of the water was altogether unusually high. It is now well known that at certain seasons of the year a very marked extension of the Gulfstream passes into the mouth of the Strait. The isotherms for September and July are shown on the chart from data kindly procured for me by Mr. Keith Johnston. Sir Edward Sabine, in an extract from his pri- vate Journal of Sir John Ross’s voyage quoted by Dr. Carpenter,’ gives a lower temperature than any hitherto recorded. He says: “Having sounded on September 19th, 1818, in 750 fathoms, the regis- tering thermometer was sent down to 680 fathoms, and on coming up the index of greatest cold was at 25°75 Fahrenheit (—3°5 C.), never having known it lower than 28° (—2°2C.) in former instances, even at a depth of 1,000 fathoms; and at other times ' Dr. Carpenter’s Preliminary Report on Deep-Sea Dredgings. Pro- ceedings of the Royal Society of London, vol. xvii. p. 186. 302 THE DEPTHS OF THE SEA. [CHAP. VII. when close to the bottom, I was very careful in examining the thermometer, but could discover no other reason for it than the actual coldness of the water.” Notwithstanding these observations and. several others telling in the same direction,—such as those of Lieutenant Lee of the U.S. Coast Survey, who in August 1847 found a temperature of 2°7C. below the Gulf-stream, at the depth of 1,000 fathoms, in lat. 35° 26'N., and 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°4C., the surface temperature being 12°5 C., the impression seems to have prevailed among physicists and physical geographers that salt water followed the same law as fresh water, attaining its greatest density at a temperature of 4°C. The necessary result of this condition, were it to exist, is thus stated by Sir John Herschel: ‘In very deep water all over the globe a uniform temperature of 39° Fahrenheit (4°C.) is found to prevail; while above the level where that temperature is first reached, the ocean may be considered as divided into three great regions or zones—-an equatorial and two polar. In the former of these warmer, and in the latter colder water is found on the surface. The lines of demarkation are of course the two isotherms of 39° mean annual temperature.” Dr. Wallich gives an excellent réswmé of this curious fallacy. He says: ‘‘ But whilst the temperature of the atmo- sphere beyond the line of perpetual congelation goes on gradually increasing, that of the water below the isothermal line rémains constant to the bottom. oHaP, VIL] DEEP-SEA TEMPERATURES. 308 Were it not for the operation of the law on which the latter phenomenon depends, the entire ocean would long since have become solidified, and both sea and land rendered unfit for the habitation of living organisms. Unlike other bodies which ex- pand and become lighter with every rise in tempera- ture, water attains its maximum density, not under the lowest degree of cold, but at 39°5 Fahrenheit ; and consequently so soon as the superficial layer of sea is cooled down to this degree, it descends, and allows a fresh portion to ascend and be in turn cooled. This process is continued until the whole upper stratum is reduced in temperature to 39°5, when, instead of contracting further, it begins to expand and get lighter than the water beneath, floats on it, becomes further cooled down, and at 28°5 is converted into ice... . Thus under the operation of an apparently exceptional law, the equilibrium of the oceanic circulation is maintained ; for whilst at the equator the mean temperature of the surface layer of water, which is 82°, gradually decreases, until at a depth of 1,200 fathoms it be- comes stationary at 39°°5, and retains that tempera- ture to the bottom, within the Polar regions and extending to lat. 56° 25’ in either hemisphere, the temperature increases from the surface downwards to the isothermal line, beyond which it remains uniform as in the former case. Hence in lat. 56° 25’ the temperature is uniform the whole way from the surface to the bottom; and as has been found by observation about lat. 70°, the isothermal line occurs at 750 fathoms below the surface.” ! 1 Dr. Wallich : North Atlantic Sea-bed, p. 99. 304 THE DEPTHS OF THE SEA. [cHaP. vir. There can be no doubt that this view, which of late years has received almost universal acceptance, is entirely erroneous. It has been shown by M. Despretz,’ as the result of a series of carefully con- ducted experiments which have since been frequently repeated and verified, that sea-water, as a saline solution, contracts and increases steadily in density down to its freezing-point, which is, when kept perfectly still, about —3°67C. (25°4F.), and when agitated — 2°55 C. The temperature observations of Sir James Clarke Ross during his Antarctic voyage in 1840-41, seemed to give support to the theory of a constant temperature of 4°5 C. for deep water, but these obser- vations have as evidently been made with unguarded instruments, as those of Sir John Ross in 1818 with instruments defended from pressure; and although I believe they must be taken as proving that in high southern latitudes the surface temperature is sometimes lower than the temperature of the water at a considerable depth beneath, still the amount of correction for pressure is uncertain, depending upon the construction of the thermometers used, and in any case it must reduce the difference considerably. A large number of thermometers of the ordinary Hydrographic Office pattern were sent out with us, as I have already mentioned, in the ‘Lightning,’ and these were of course the instruments used by Staff-Commander May for his temperature obser- vations. There was an opportunity of testing these thermometers, however, on the return of the vessel, ? Recherches sur le Maximum de Densité des Dissolutions aqueuses. Loc, cit. CHAP. VIL] DEEP-SEA TEMPERATURES. 305 so that we are tolerably certain by actual experi- ment of the amount of their error. In speaking of the ‘Lightning’ temperatures, I mean, therefore, the actual temperatures taken by the ordinary ther- mometers, corrected approximately to the standard of the Miller-Casella thermometers, afterwards used in the ‘ Porcupine.’ Leaving Stornoway in the ‘ Lightning,’ on the llth of August, 1868, and directing our course towards the Féroe banks, we sounded in 500 fathoms about 60 miles to the north-west of the Butt of the Lews, and took a bottom temperature of 94 Cent. with the ordinary Six’s thermometer— the only form of the instrument in use at the time. This, when corrected for pressure, gives about 7°8 C. We were surprised to find the temperature so high, and we were at the time inclined to think that the observation, which was taken in a breeze of wind, was scarcely to be depended upon. Subsequent observations, however, in the same locality, con- firmed its accuracy. On the Féroe Banks, at a depth under 100 fathoms, the bottom temperature averaged 9°C., while that of the surface was about 12°C. ; temperature indications on this bank were, however, of little value, as the water is no doubt affected to some extent through its entire depth by direct solar radiation. The next observation was in lat. 60° 45’ N. and long. 4° 49’ W., at a depth of 510 fathoms, with a bottom temperature of —0°5C., about 140 miles nearly directly north of Cape Wrath. Then followed a series of sound- Ings, Nos. 7, 8, 10, and 11 of the chart (Plate: J), taken while traversing the northern portion of the x 306 THE DEPTHS OF THE SE.t. [cHAP. VIL channel between Scotland and the Féroe plateau ; and giving, respectively, the temperatures of —1°1, —1°2, —0°7, and -0°5C. No. 9, with a depth of 170 fathoms and a temperature of 5° C., is excep- tional; it is apparently the top of a circumscribed ridge or bank. We dredged at this station and got large numbers of the rare and beautiful Terebratula cranium ; but when we tried for the same spot in the following year in the ‘ Porcupine,’ we could not find it. On the 6th of September we sounded and took temperatures in lat. 59° 36’ N., long. 7° 20° W., in 530 fathoms, when the mean of three thermometers, which only differed from one another by about 3 of a degree, gave a bottom temperature of 6°4 C. A temperature sounding, at the moderate depth of 189 fathoms, was taken on the morning of the 7th September in lat. 59° 5’ N., long. 7° 29’ W., and gave a bottom temperature of 9°6 C. The three soundings, Nos. 13, 14, and 17, at the depths 650, 570, and 620 fathoms, extending into the North Atlantic as far westward as long. 12° 36’ W., gave a bottom temperature of 578, 674, and 6°6 C., respectively. The general result of these observations we could not but regard as very remarkable. The region which we had somewhat imperfectly examined in- cluded, in the first place, the channel about a couple of hundred miles in width, with an extreme depth of rather under 600 fathoms, extending between the northern boundary-line of the British plateau and the shoal which culminates in the Firoe Islands and their extensive banks; and secondly, a small portion of the North Atlantie extending westwards CHAP. VII] DEEP-SEA TEMPERATURES. 307 and northwards of the western entrance of the channel. We found that in these two areas, freely communi- cating with one another and in immediate proximity, two totally different conditions of climate existed at all depths below the immediate surface, where they differed but slightly. In the Féroe channel, at a depth of 500 fathoms, the bottom temperature aver- aged —1°0C., while at a like depth in the Atlantic the minimum index stood at + 6° C., a difference of 7 degrees Centigrade, nearly 13 degrees Fahrenheit. The conclusion at which we speedily arrived as the only feasible explanation of these phenomena was that an arctic stream of frigid water crept from the north-eastward into the Féroe channel lying in the deeper part of the trough, owing to its higher specific gravity ; while a body of water warmed even above the normal temperature of the latitude, and therefore coming from some southern source, was passing northwards across its western entrance and occupying the whole depth of that comparatively shallow portion of the Atlantic from the surface to the bottom. Several important facts of very general applica- tion in Physical Geography had been placed beyond doubt by these observations. It had been shown that in nature, as in the experiments of M. Despretz, sea-water does not share in the peculiarities of fresh water, which, as has been long known, attains its maximum density at 4° C.; but, like most other liquids, increases in density to its freezing-point: and it had also been shown that, owing to the movement of great bodies of water at different temperatures In different directions, we may have in close proxi- x 2 308 THE DEPTHS OF THE SEA. (cap. Vix, mity two ocean areas with totally different bottom climates—a fact which, taken along with the dis- covery of abundant animal hfe at all depths, has most important bearings upon the distribution of marine life, and upon the interpretation of paleonto- logical data. The conditions during the ‘ Lightning’ cruise were so unfavourable to careful observation, that we deter- mined to take the earliest opportunity of going over this region again, and determining the limits of these warm and cold areas, and investigating their con- ditions more in detail. Accordingly, in the follow- ing year, when we had H.M.S. ‘ Porcupine’ at our disposal, Dr. Carpenter and I once more left Storno- way on the 15th of August, 1869. On this occasion we had everything in our favour; the weather was beautiful, the vessel suitable, and we were provided with Miller-Casella thermometers on whose accuracy we could depend. 7 Pe5 10 147 | 155 ee 10 139 | 12°2 ; Midn.! 150 | 14°7 t Copeland Is- * ' August 8th . 2 13:9 | 15°0 ne j| Noon} 14-4 125 gu a \ 4p | ae 2 150 | 13-9 6 4 lel |} 16) 8 15:0 | 15-0 6 16°6 | 15°8 10 155 | 153 § | 133 At Belfast Noon.! 17:2 | 15°8 10 13°3 | 15:0 2 208 | 161 Midn.| 11:1 | 13°9 4 16°6 | 15°8 August 5th . 2 irl | 14] 6 Ig’ | 165 4 10°5 | 14°4 8 14:4 | 15°8 6 12°7 | 146 10 13°6 | 15°8 8 153 | 147 Midn.| 13°9 | 15°5 10 183 | 150 August 9th . 2 1973 5 159 At Belfast Noon.| 16°9 | 15°5 4 ie | Ie 2 17°4 6 13°3 | 15°3 4 17-7 | 16°4 8 i353 6 12°8 | 155 10 14°4 | 155 8 At Belfast Noon.| 15°0 | 15°5 10 111 | 15°0 2 161 | 15°5 Midn.| 10°0 | 15:0 | 4 16°6 | 15°5 August 6th . 2 | 105 | 14-7 | 6 | 144 | 158 4 vO | 144 8 114 | 155 6 125 | 141 10 10°5 | 15:0 8 166 | 144 { Midn.! 10°0 | 14°4 340 THE DEPTHS OF THE SEA. (citar, vit. o ry 3 > oo B se 33 és eH | Be Date and Position. 8 aa a4 Date and Position. 5 a3 Ba | ze E3 | ES ES o o 3 Ban a Ay a ee Deg. oe Cent, oak, Ga. August 10th. 2 111 | 139 |, August 13th. 2 | 135 | 116 4 105 | 14:7 4 | 127 | 122 6 105 | 144 6 13°3 | 116 8 ll-4 | 144 8 12:0 | 127 10 139 10 114 | 116 At Belfast Noon.| 15°5 | 15:0 Midn.} 111 | 12-2 2 | 15-0 August 14th. 2 | 116 | 19-0 4 147 4 114 | 11-4 6 12°7 6 114 | 129 8 11'9 | 15°0 8 13°3 | 12°0 10 116 | 144 10 12°7 Midn.| 11°6 | 13:9 || At Stornoway . | Noon.| 15°5 | 19°2 August 11th. 2 | 105 | 13:9 2 | 161 | 125 4 117 | 13:3 4 15°0 | 12°7 6 122 | 136 6 147 8 13°3 | 13°9 8 | 13:3 | 129 10 14:4 10 13°3 | 12°5 In Belfast Lough | Noon.| 14-4 | 14°4 Midn.| 12°7 | 122 2 15°3 | 122 || August 15th. 2 13°3 | 122 4 150 | 13°0 4 | 133 | 122 6 139 | 12°2 6 13°3 | 12:2 8 12:°2 | 12°2 8 13°9 | 122 10 i i da i 10 13'9 | 122 Midn.| 12°0 | 11°7 || At Stornoway Noon.| 14°4 | 122 August 12th. 2 |} 122° | 129 2 | 158 | 125 4 11 | 117 4 | 161 | 12% 6 114 | 12°0 6 155 | 125 8 13°3 | 12°5 8 13°3 | 12°5 10 172 | 12°7 10 | 127 | 127 Coll Island, x . Midn.} 13:0 | 122 North, 3 miles ame Wee || Tes August 16th. 2 | 127 | 122 | 2 153 | 13°3 4 | 127 | 122 4 144 | 122 6 | 133 | 12:2 6 12°7 | 12:2 8 | 133 | 12°2 8 12:2 | 12°0 2 < 10 | 136 | 122 10 Lh?) 12:2 at. 59°21’ N. ‘ 3 Midn.| 12:0 | 12:2 | Long. 6° 58’ W. Noon.) 133 | 120 August 13th. . 2 | 127 | 116 2 | 130 | 122 4 125 | 116 4 | 133 | 122 6 12°77 | 12-0 | 6 13°3 | 12% 8 12°5 | 12°0 8 LORE VBR « 10 | 147 | 116 10 | 5 | ie Shiant Islands, ) ae . Midn.} 12°2 : N.N.W. 6 miles § Noon.| 133 | 116 August 17th. . Q ‘411 | 116 t CHAP. VIL] DEEP-SEA TEMPERATURES. 341 roy 2 ry oe f | 2 2. | Be a SH Ba ane 4 ge 3 3 | Date and Position. s ga 2a Date and Position. = ea eo | ge | oe | Be | Be a Be a ae Deg. 3 ae ook, iceeawe se cont | ee August 17th. 4 | 192 | 11-9 at. 60° 35’ N. is 4 gu 6 | 13:2 | 11-9 || Long. 6° 41’ W. ! Noon.| 13°3 | 11°4 8 12°2 2 127 | 11'4 10 139 | 12:2 ao i Lat. 59° 36’ N. : ae) Ts 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 | 130 | 11:9 || August 21st . 2 | 100 9-4 8 12°5 | 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 12°2 | 10°5 ar ee : 10 13°6 97 4 ted 7 2th andi in { . ; 6 | 127 | 111 Féroe Islands § Pega.) lee a \ 8 13°9 | 114 2 114 88 : x) 10 13°6 | 10°8 4 17 91 at. 60° 25’ N. Be J 6 11°4 91 Long. gs OW. 5 Noon. 13°6 114 8 10°5 91 : 2 12°77 | lil 10 10°8 94 | 4 12°5 | 108 Midn.| 10°5 9°4 6 io | 211 August 22nd 2 10°5 91 8 Ia | Atl 4 10°8 9°4 10 12° | 111 6 Led 91 Midn.| 12°2 | 11:1 8 116 9-4 August 19th . 2 TOO | VL 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 | 11°4 4 12°2 | 10:0 enna 10 13°3 | 11°4 6 13°3 97 at. 60°13" N. ; ; 8 | 105 | 9-4 Long. 6° Ay WwW. i Noon. 12 7 Ill 10 10-0 9°4 2 13°3 | 111 Midn, | 10:0 9°4 4 139 August 28rd 2 94 94 i 6 12°77 | 1171 4 | 8 | 127 | 111 6 | 108 | 9-4 10 T2274 IA 8 10°5 9°4 Midn.| 12°2 | 10°5 10 12°7 9°7 August 20th. 2 | 122 | 105 }) 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 6 122 9°4 10 12°5 | 103 8 11°6 91 342 THE DEPTHS OF THE SEA. (cHAP. VII. Temperature of Air Date and Position, 3 a Deg. Cent. August 23rd 10 | 111 Midn.) 11°1 August 24th. Q | ill 4 lil 6 ule ae 8 11-4 About 10 miles | ile ou miles ( Be East of Haalso § Noon. | 15° 2 12°0 4 13°3 6 Tal 8 lll 10 10°5 Midn.} 1171 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 8 114 10 114 Midn.| 12°0 August 26th. 2 | 120 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 1 8 {116 10 116 Midn,} 11°4 August 27th, 2 | 11 4 Lt 6 11), eo ov vo EG Date and Position. 5 a4 ge oa fan Bou as Ea a° | Ba Es A Ae Deg. Deg. Deg. Cent. Cent. Cent, 9-4 |; August 27th. . 8 | 111 | 114 91 Lat, 60° 96'N, } 10 | 116 | 116 OT ab. . 3 9:4 Long. 0° 15’ E. § See 125 | 116 94 2 13°3 | 12-2 91 4 | 122 | 119 91 6 lll | 119 91 8 LVL | 22¢ 10 10:0. |) F262 97 Midn.; 9°4 | 111 10°0 August 28th. 2 10°5 | 116 94 4 2 | iP6 94 6 Leo | Teg 9°4 8 10°0 | Ill 9°4 10 100 | 111 9-7 || At Lerwick . . !Noon,! 9-4 | 111 97 2 108. | Ill 94 4 TEL. |e 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 3 114 97 8 94 | 111 91. 10 97 | lll 10°5 |; At Lerwick . ‘Noon.| 9°4 | 111 tl 2 94 | Ill PPL 4 94 | 111 Ei. 6 Q1 | Ill 11°4 8 Te | Ue 116 10 77 | 108 11-4 Midn.| 89 | 10°8 August 30th. 2 83 | 111 114 4 Ta 11-4 6 8:3 | 108 114 8 103 | 111 11°4 10 THI | Veh 111 |) At Lerwick . Noon.| 11°6 | 111 Til 2 a7 | 114 t4 4 122 | 111 LeL Y 6 LS 8 Wee | Ua CHAP. VII.] DEEP-SEA TEMPERATURES. 343 s 28 g es » | Be | 28 w | fe | £€ Date and Position. 3 Eq EA Date and Position, 3 Bq ca mw | 23 | 26 = | Bs | Fs = Ba Bo | ES B Ete a Fas Gent. | Cent Genk | seen August 30th. 10 72 | 111 ae oo : 10 13:0 | 116 Midn.| 66 | 11‘L at. 60° 3° N, ‘ an August 31st . 2 | 721105 || Long. 5°10 W. 5 | Noow.) 12-7 | 11°6 4 77 | 105 2 12°5 | 116 6 10°0 | 111 4 Tee Peg 8 100 | 111 6 12°2 | ll-4 10 11°6 | 10°8 8 12°59 | il4 At Lerwick . Noon.) 12°2 | 11°1 10 | 127 | 116 2 13°6 | 111 Midn.) 12°7 | 12°2 4 WET. 1 September 4th , 2 12°7 *| 12-2 6 105 | 111 4 13°3 | 122 8 ALi | ill 6 139 | 125 10 10°8 | 10°8 8 13°9 | 12°5 Midn.} 10°5 | ill 3 Nj 10 14-4 | 12°2 September Ist . 2 | 111 {11:1 || Lat. 59° 43’ N. aha aes 4 | 101 | 116 i Loug, 6° 35° Ww, | Noon.) 183 | 122 6 116 | 116 2 13°3 | 13°2 8 11°6 | 116 4 13°0 | 12°2 10 lll | 114 6 Loe | 199 Lat. 60° 27° N. 4 , 8 127 | 116 Long. 3° LI’ W. Noon) TET | 116 10 | 122 | 116 2 122 | 116 Midn.} 12°5 | 12:0 4 | 13° | 114 || September 5th . 2 | 122 | 12°0 6 TEs: ot 1. 4 12:5) | TIR6 8 4 | 111 6 Vag | EG: 10 111 | 11°6 8 12°7 | 116 3 : Midn.| 1111 | 11°6 ~ 10 13°3 | 12:0 eptember 2nd. | 2 | 108 | 10°8 |) Lat. 59°38’ N. ) poll ane 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 He eaeaae-n, 10 Ill | 103 6 Ill | 116 at, ¢ 7 F 8 111 | 116 Long, 4° 38 W. Noon.} 114 | 10-0 10 | 108 | 114 2 114 | 103 |]. Midn.! 111 | 114 4 | 116 | 10 || September 6th . 2. (ATRL | Led, 6 Ilé6 | 111 4 lll | 14 8 Ped aed 6 122. ALG 10 11°6 | 11°4 8 130 | 116 daidnecens Midn,} 111 | 116 " 10 12°7 | 12:0 eptember 3rd . 2 116 | 111 at. 59°37’ N, : S 4 | 111 | 111 | Long. 9° 4’ W. Noon.| 12°7 | 12-2 6 111 | 116 2 13°0 8 116 | 116 4 12°7 | 122 344 THE DEPTHS OF THE SEA. [cwap. vi. | Oo o 3 Oo oo Date and Position. | 2 BA | 82 Date and Position, 8 ea | 82 |) H | gs | Bs Bo) es | Bs | & | ag & | 8% Deg. Deg. Deg. Cent. Cent. | Cent. September 6th . 6 122 September 10th 144 | 12-7 8 12°2 15:0 | 12°7 10 122 13°9 | 12°7 Midn.| 11°6 At Stornoway . 16°3 | 13°3 September 7th . Q | 114 16°3 | 13:9 4 10°5 15°0 | 13°6 6 10°5 13°9 | 13:3 8 12°2 12°7 | 133 ‘: ae 10 14:7 122 | 13:0 at. 59° 41’ N, 5 116 | 127 Long. 7° 32’ W. Noon.| 15° September 11th Ill | 127 2 13°9 LV] 3 197 4 13°3 111 | 12°7 6 12°7 PET || 97 8- | 12°5 13°9 | 12°7 10 | 12-7 At Stornoway 153 | 12°7 Midn.| 12°2 13°3 | 12°2 September 8th . Be || TOD, 116 | 12°7 4 12°7 114 | 12°7 6 12°7 10°8 | 12°7 8 13°6 97 | 122 ‘ ae 10 150 & ‘ - 94 | 12:2 at. 59° 7’ N, : eptember 12t! 91 | 12°2 Long. 6° 35° W. Noon.| 14°4 si 89 | 122 2 153 94 | 122 4 155 114 | 12:2 6 13°3 12°5 | 122 8 | 133 At Stornoway 12°7 | 122 10 13°3 12°7 | 125 Midn. | 12°7 12°7 | 125 September 9th . 2 | 133 111 | 12:2 4 13°3 105 | 12:2 6 133 10°0 | 12°2 8 13°0 Ill | 12°0 10 13°3 September 13th 10°0 | 11°6 At Stornoway Noon.} 13°9 91 | 111 2 111 | 116 4 14-4 111 | 11°6 6 153 13:0 | 122 8 | 155 In Loch Sheil- ‘ , 10. | 155 dag, 3. ys ee Midn.| 15°5 141 | 122 September 10th 2 | 139 14:4 | 122 4 144 13°9 | 122 . CHAP. V1.] DEEP-SEA TEMPERATURES. 845 g 28 2 28 nositi s | #2 | 22 g | ae | #2 Date and Position. & 34 os Date and Position. & ga 32 B° | Ba B° | ga a Fey a Be Gam. | Come | geek | Gene September 13th 8 | 13:0 | 12-2 |) Abreast of Mull | Noon.| 12°7 | 13°0 10 12°2 | 12-2 2 144 | 13°3 Midn,| 12:2 | 122 4 144 | 13:3 September 14th 2 116 | 125 6 136 | 12°7 4 12°2 | 12°2 & 13°0 | 13°3 6 12°5 | 122 10 12°5 | 13°0 8 122 | 12°7 Midn.} 12:0 | 13°0 10 116 | 12°7 II. Surrack TEMPERATURES OBSERVED DURING THE SuMMER OF 1870. | | um | § | 24) Be gall (eee ee Date and Position. & Bi ae Date and Position. 4s a, ae Be | 38 | Bs A As a 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 | 147 | 147 Midn.| 16°6 | 16°4 10 | 15°3 | 13°6 || July 8th . 2 | 166 | 161 Off Scilly Islands | Noon.| 18°6 | 18°3 4 | 161 | 161 2 | 19°7 | 17-4 6 | 169 | 161 4 | 194 | 183 8 | 191 | 162 6 | 18°9 ie i 10 | 20°8 | 161 8 | 17-4 | 17° at. 48°31' N. ; . 10 | 166 | 17-2 |! Long. 10° ow} Noon.| 19°6 | 17°2 Midn.} 161 | 17°2 2 | 20:0 | 17°5 July 7th . 2 | 166 | 166 4 | 186 | 17°5 4 | 166 | 166 6 | 191 | 175 6 | 166 | 166 8 | 177 | 17-2 8 | 169 | 169 10 | 169 | 17°2 Lat, 48° 49 N) 10 | 17°7 | 16°4 Midn.| 16°6 | 16°9 at. 48° 49’ N. ‘ .4 || July 9th . 2 | 161 | 16:9 Long, 9° 35’ w, { | Noon.| 18:3 | 164 y 4 | a6 | 460 2 | 194 | 164 6 | 161 | 166 4 | 189 | 17:2 8 | 161 | 166 346 THE DEPTHS OF THE SEA. [cHap. VII. 3 | £4 | #3 § Date and Position. & zs 5 Date and Position. & & BS Deg. Deg. Cent. Cent July 9th. . 10 | 175 | 166 |) July 12th 6 Lat. 48° 26’ N. : 4 8 Long. 9° 43' Ww. Noon. | 17°5 16°6 10 2 16°4 | 16°6 Midn. 4 172 | 166 | July 13th 2 6 164 | 166 4 8 16°4 | 1671 6 10 166 | 16°6 8 oe ‘ Midn.| 16:1 | 16°4 " < 10 uly 10t 2 161 | 166 at. 44° 59’ N. c 4 | 16-4 | 164 || Long. 9° 33° W, {| Noon. 6 16°6 | 16°4 2 8 164 | 16°4 4 a < 10 173 | 166 6 at. 48° 28’ N. _ ; 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 G1 | 161 8 Midn.| 161 16'1 10 July 11th 2 | 161 | 166 | Cape Finisterre, 4 | 164 | 164 EL N.N. Noon 6 | 164 | 161 10 miles . 8 18°3 | 16:1 2 ‘ < 10 18°6 | 166 4 at. 48° 8'N, 4 : 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) WA |) WAT 10 4 VT. | TE Lat. 42° 11’ N. N 6 | 17-4 | 180 || Long. 9° 13’ W, eee 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 '17'7 | 180 Midn. Temperature of Air Cent. 179 16°6 16°6 16°6 ges 175 17°7 18°6 18°9 19°7 21°1 22°5 211 175 175 17'2 17'7 LEQ 16°9 183 18°6 18°6 18°6 191 175 166 16°6 16°6 166 16°6 175 183 189 20°0 22°3 21°2 19°0 17°9 17-7 18°9 Temperature of Sea-Surface. 158 15°8 15°8 155 15'8 16°1 16°1 16°6 16°4 16°9 17°2 16°4 175 179 18'9 189 189 19°3 CHAP. VII. ] DEEP-SEA TEMPERATURES. 347 Date and Position. July 16th At Vigo . July 17th | At Vigo . July 18th | | | Lat. 41° 55’ N, Long. 9° 30’ W. _ July 19th | Lat. 40° 16" N, Long. 9° 33’ W. Hour. io SOMOS ALD a OABOs 5 E. 2 SO mh to By Z or ° B OB DO BAS Go TH bo it me Oo ae | # § ea | @ a ae Date and Position. 8 Es ae a as a Ay Deg. Deg. Deg. Deg. Cent. | Cet. 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 | 17:9 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 18°3 | 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 | 2174 17:5 | 16:5 2 25°5 | Qi°1 17°'7 | 16°6 4 | 26:3 | 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 20°0 | 16°5 8 | 22°7 | 19°4 186 | 162 a 7 10 24:5 | 19°4 18°3 | 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 ae ee 10 | 196 | 19-4 186 | 16°3 Midn.} 19°5 | 1971 189 | 16°3 July 22nd 2 194 | 189 189 | 164 4 | 189 | 18°9 183 | 16°6 6 | 20:0 | 18:2 183 | 16°6 8 | 212 | 18:3 a 16'4 fe 10 | 25°0 | 19°4 Lz" 169 e arilhoes. 177 | 169 || SSE. 5 miles Noon.} 250 | 18:9 19°4 | 169 2 | 239 | 191 20°38 | 175 4 | 23°3 | 20°5 20°71 | 17°7 6 23°9 | 194 x “ 8 20°0 | 19°4 208. | ee 10 | 189 | 18:3 [cHar. VIL. 348 THE DEPTHS OF THE SEB4. 2 | g$ 2 a Bs B = B4 3 5 q B.5 Date and Position. & a Pe Date and Position. g Be & Bs a eg. d Mid cet. | 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 | 200 6 | 205 | 183 4 | 200 8 | 23°3 | 20°5 6 | 20-0 10 | 24-7 | 22:0 8 | 19:4 At Lisbon Noon.| 22°5 | 2171 10 | 20:0 2 | 23-6 | 191 Midn. | 20:0 4 | 21:6 | 20°0 || July 27th 2 | 19-4 | 6 | 23-0 | 216 4 | 19-4 8 | 205 | 203 6 | 19°4 10 | 195 | 197 8 | 200 Midn.! 20:1 | 19°5 ' 10 | 21:3 July 24th 2 | 194 | 186 || Lat. 37°18" N. 4 | 19-4 | 205 || Long. 9°12 w. 5 | Noon) 211 6 | 201 | 21°6 2 | 233 8 | 20°83 | 20°8 4 | 911 10 | 21-2 | 2071 6 | 20:0 At Lisbon Noon.| 24:1 | 19°4 8 |} 20°0 2 | 23-0 | 205 10 | 19-4 4 | 231 | 2071 Midn.| 19:5 6 | 222 | 21-2 || July 28th 2 | 194 8 | 20% | 21-4 4 | 194 10 | 200 | 20:0 6 | 191 Midn.| 19-4 | 19°7 8 | a1 July 25th 2 | 191 | 20-0 10 | 201 4 } 19:0 | 200 || Lat. 36°55" N. ; 6 | 20:3 | 191 || Long 8°44 w. 5 |Noom.| 21°8 8 | 20-4 | 19:4 2 | 216 10 | 20°8 | 19:1 4 | 216 Lat. 38° 10’ N. ; 6 | 205 Long. 9° 29’ W. Noon.] 21°8 | 19°4 8 | is-9 2 | 211 | 19-4 10 | 189 4 | 208 | 19-4 Midn.| 18°6 6 | 216 | 194 || July 29th 2 | 183 8 | 20:0 | 18-0 4 | 183 10 | 186 | 17°7 6 | 211 Midn.| 18:0 | 17°7 8 | 221 July 26th 2 | 183 | 17-4 10 | 23:0 4 | 183 | 17-7 || Lat. 36°45" N, : 6 | 19:1 | 191 | Long 8° 8 w. 5 | Noom-| 233 8 | 194 | 191 2 | 233 10 | 203 | 193 4 | 248 Temperature of Sea-Surface. CHAP. vit.] DEEP-SEA TEMPERATURES. 349 cu o3 o og 5 Ze ES 2g E Ba & 4 @ & iti & Sq Sw Date and Position. 5 34 Sa Date and Position. 3 ee 2 F q BS z 3 a By Se By Deg. Gant: | cae Gone | Genk 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. § Re ec July 30th 2 20'°3 | 21°9 2 22°5 | 23:0 4 20°5 | 22-2 4 22°7 | 23-0 6 20°5 | 22°8 6 21°8 | 22°8 8 Q2'4 | 22°5 8 212 | 92-9 10 B33 | 22:9 10 21°3 | 29'5 Lat. 36° 27’ N. af ae Midn.} 211 | 22°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 | Be 6 21°8 | 99°8 6 925 | 242 8 23°7 | 22-2 8 216 | 2471 . 10 23°3 | 21°8 10 216 | 24°3 at. 35° 39° N. és . Midn.| 21°5 | 24-3 || Long. 7° 4’ W. {| Noon.| 21°6 | 22-0 July 31st. 2 Qi-1 | 22°8 2 22°6 | 999 4 219 | 23°3 4 241. | 222 6 219 | 23°6 6 23°2 | 29°9 8 O95 | 241 8 21°8 | 29°29 10 945 | 239 10 21°8 | 22:0 At Cadiz . Noon.| 25°2 | 24°0 Midn. | 22°5 | 23:0 | 2 Q51 | 241 August 4th . 2 22°2 | 99-9 | 4 | 24:0 | 243 4 | 299 | 99-9 6 940 | 24°4 6 23°2 | 99°9 8 93'°4 | 244 8 23°9 | 22°9 aes Q2°7 | 24-1 ? 10 24°4 | 93°3 idn.| 22°56 | 24°] at. 35° 35’ N. t 3 Angust Ist 2 | 223 | 93-9 || Long. 6° 24 w. {| Noon-| 25°0 | 23:3 4 216 | 22°8 2 272 | 23-4 6 225 | 23°9 4 25°6 | 23°3 8 944 | 947 6 24°4 | 93°3 10 Q4°1 | 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 | 22-2 4 | 236 | 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 eat Midn.} 21°8 | 23°9 10 221 | 21°5 ust 2nd , 2 | 21:9 | 23°3 || In Strait — of : % 4 | 213 | 23:0 || Gibraltar . Moon, | 288° | 22 6 21°6 | 23°3 2 24-1 | 23°4 [cHAP. v1, 350 THE DEPTHS OF THE SEA. 5s | £2 | #2 Date and Position. 5 Be) ee Date and Position Be | 55 A Bs Deg. Deg Cent. Cent, October Ist . 4 | 225 | 228 || October 5th . 6 22°0 | 22°6 8 2V1 | 29°5 10 215 | @22 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 : 10 24°7 | 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 | 211 | 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. Midn. 6 10 Noon. Temperature of Air. CHAP, VIt.] DEEP-SEA TEMPERATURES. 3501 8 £ g 23 a a4 ad Date aud Position. 3 Bigs 23 Date and Position. 3 Bae £3 E> | Be | ga a a be] A a = Deg. Deg. Deg. Deg. Cent Cent. Cent. Cent. St. Alban’s Hd., October 8th . 6 | 150 | 15°8 English Chan- >| Noon.| 18°6 | 16:2 8 | 147 | 157 mel. 2... 10 155 | 15°6 Midn.| 15°3 | 15°5 195 | 16:0 || At Cowes He bo = ae a e or a 35 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. SeRiaL, SOUNDINGS. | Bottom Sounpmncs. Tempe-|Tempe-|Tempe-|Tempe-|Tempe-/Tempe-|Tempe-| Sta- Surface | Bottoin 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. eane Gent. Cent. Gai, ene Cent. Fms. Cent. Cent. 0 | 14:0 | 17:0 | 13°8 | 12°6 | 18-0 | 13-4 | 17-7 50 ae 18 27 54 13+1 0) 34 76 18°9 9°8 6 90) 12:2 10-0 35 96 17-4 Lee 100 91 | 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 97 250 aon 10°1 91 8-9 91) 9-0 | 10-2 4 251 12-0 oy 300 87 ed 26 345 14:1 8-1 350 ace 95° 1 370 12-2 9-4 400 86 91 ao 422 2 8:3 450 ee 86 45 458 15°9 8-9 500 We 85 81 81 83 86 8°8 40 517 | 17-4 87 550 ie 8-0 39 oor | 172 83 600 ag 75 41 584 | 17:4 8-0 630 63 650 68 23d 664 14-1 5:3 700 64 12 670 | 11:2 59 3 723 125 61 36 (20 | Itt 66 750 583) 55) 51] 53] 57) 5:2 800 55 2 808 | 12:3 5-2 16 816 | 11:6 41 862 4:3 44 865 | 16:2 41 1000 ‘ 37 3°6 37 36 35 43 1207 | 165 3-1 28 1215 | 14:2 28 17 (| 1230; 11:8 32 1250 31} 32) 341 29 | 1264 | 13:8 27 1300 32. | 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 Baswn. Sration 42. Station 23. Srarron 87. Lat, 49° 12’. Lat. 56° 13’. Lat. 59° 85’. Depth. So Difference ia a Difference. sae oe Difference. Fathoms, Surface. 17° 0C. 14° 0C. 11" 4C. 6° 4C 4° 90, 2° 9 C. 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 O°l 0°3 400 9°1 8°6 728 1°0 1°'0 0°5 500 8:1 7°6 Was 0°6 0°77 1°2 600 TB 6°'9 6°1 1°‘7 750 5°8 0-9 767 5:9 354 THE DEPTHS OF THE SEA. APPENDIX D. [crar. vir. 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. Warm AREA, CoLp AREA. Series 87. Sta- Surface Bottom Series 64. Ser, 52. | gta. lia Bottom - pl Depth. vempe: psinves ao Depth. Tempe- ig empe- oO. rature, | rature. e = = | NOs. Ty 7 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 | dl 9°8 11 59 8-9 | 73 84 | 15 | 9:3 50 75 91 70 | 66 (119) 7:3 80 92 | 118] 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 3800 81 300 0-2 | --0-7 63 | 317 | 94|—10 65 | 345 | 111} -12 76 | 344 | 10-2 | -13 50 | 355 | 114] 79 || 350 | —0-3 54 | 363 | 11-4 | —03 46 | 874 | 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 1 499 | 112) -11 500 | 72 500 | —1-1 X. | 500 | 105 | -07 XIE | 530 | 11-4) 71 58 | 540 | 10-8 | —07 47 | B42 | 122] 6-5 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 ’ XVII} 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. 355 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 ie apeas | Tempers: Bet | opt; Moteparas || Uempere eae 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 76 112 93 78 290 112 53 73 84 115 9°3 82 312 113 51 71 103 11°6 92 83 362 11°8 3°0 74 203 14 87 66 267 lit 76 15 440 10°9 56 AA 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. Au 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-STREAM. 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 ‘ 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 oe . . 1841 25 10 7 59 ER. 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. Faths. 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 48 ye + 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 22 Lenz. . . 1834 32 57 176 42 E. 782 | 164 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. ouap. 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 2°7 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. VIII. 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. cap, vu1l.] 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 ———s = Ir ‘hing fo yyuow ay2 4of pungouadouag fo woynguuysryp pouruab ayy puw ‘yadop oy) Burmoys < omunyy YMON °Y? fo pny yooshyg— TIA FLV1g ee 5 ee Soh) ot & é : TLUON got ENWILV |HLNQN 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°83 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. cHapP. VIII.] 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 Tbid. 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.”’1 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, BB 370 THE DEPTHS OF THE SEA. [cHap, 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 surface-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.] THE GULF-STREAM. 371 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. [omar. vit, 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-STREAM. 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 874 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. VIII] 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. vii. 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. Vill. | 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. VIL. 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. 8379 “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- ? Nature, vol. iv. p. 7L 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, VII] 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 16° 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, VuII. 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. CHAP, 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 Gulfstream 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 aline 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, 800, 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 sufii- cc2 388 THE DEPTHS OF THE SEA. [cHap. vit. 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. Mr. 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- cHar. vil] THE GULF-STREAM. 391 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 VITI.). 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, cwAP. 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° C. 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 3800 fathoms. This proves that the Gulf-stream water fills the whole of the channel, contrary to what is the case in the Féroe-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. ViII.] 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. (cuap. 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. vir. 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 DEPTHS 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. VIII.) 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. TE 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. AOS 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. 418 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. Ix, 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 Astrorhiza, Lituola, and Botellina are gigantic—large examples 30 mm. long by 8 mm. in diameter. The few hauls of the dredge which we have already had in deep water have been enough to teach us that our knowledge of sponges is in its infancy,—that those which we have collected from shallow water along our shores, and even those few which have been brought up from deep water on fishing lines, and have surprised us by the beauty of their forms and the delicacy of their lustre, are the mere margin and remnant of a wonderfully diversified sponge-fauna which appears to extend in endless variety over the whole of the bottom of the sea. I cannot attempt here more than a mere outline of the general cha- racter of the additions which have been made to our knowledge of this group. The sponges of the ‘ Por- cupine’ Expedition are now in the hands of Mr. Henry Carter, F.R.S., for description; and an ex- cellent sketch of the sponge-fauna of the deep Atlan- tic, bringing information on certain groups up to a late date, has been published by the best authority we have on sponges, Professor Oscar Schmidt of Gratz. cHaP. VIL] THE DEEP-SEA FAUNA. 417 As I have already said, the most remarkable new forms are referable to the group which seems to be, in a sense special to deep water, the. Hexactinellidee. I have already (p. 70) briefly described one of the most abundant and singular forms belonging to this order, Holtenia carpenteri; and all the others, though running through most remarkable variations in form and general appearance, agree with Holtenia in essential structure. In the Hexactinellide all the spicules, so far as we know, are formed on the hex- radiate plan; that is to say, there is a primary axis, which may be long or short, and at one point four secondary rays cross this central shaft at right angles. Very often one-half of the central shaft is absent or is represented by a slight rounded boss, and in that case we have a spicule with a cross-shaped head, a very favourite form in the manufacture, defence, and ornament of the surface layer of these sponges; and often the secondary rays are undeveloped: but if that be so,—as in the long fibres of the whisp of Hyalonema,—in young spicules and in others which are slightly abnormal, four little elevations near the middle of the spicule, which contain four secondary branches of the central canal, maintain the permanence of the type. In many of the Hexac- tinellidee the spicules are all distinct, and combined, as in Holtenia, by a small quantity of nearly trans- parent sarcode; but in others, as in ‘ Venus’s flower- basket,’ and the nearly equally beautiful genera Iphiteon, Aphrocallistes, and Farrea, the spicules run together and make a continuous silicious net- work. When this is the case the sponge may be boiled in nitric acid, and all the organic matter and EE 418 THE DEPTHS OF THE SEd. (cHAP, VII. other impurities thus removed, when the skeleton comes out a lovely lacy structure of the clearest glass. The six-rayed form of the spicules gives the network which is the result of their fusion great flexibility of design, with a characteristic tendency, however, to square meshes. On the 30th of August, 1870, Mr. Gwyn Jeffreys dredged in 651 fathoms in the Atlantic off the mouth of the Strait of Gibraltar an exquisite sponge, resembling Holtenia in its general appearance, but differing from it in the singular and beautiful cha- racter of having a delicate outer veil about a centi- metre from the surface of the sponge, formed by the interlacing of the four secondary rays of large five- rayed spicules, which send their long shafts from that point vertically into the sponge body (Fig. 65). The surface of the sponge is formed of a network of large five-radiate spicules, arranged very much as in Hol- tenia; but the spicules of the sarcode—the small spicules which are imbedded in the living sponge-jelly —are of a totally different form. A single large ‘osculum’ opens, as in Holtenia, at the top of the sponge, but instead of forming a cup uniformly lined with a netted membrane, the oscular cavity divides at the bottom into a number of branching passages as in Pheronema anne, described by Dr. Leidy. I was inclined at first to place this species in the genus Pheronema, but Dr. Leidy’s descrip- tion and figure are by no means satisfactory, and may refer to some other form of the Holtenia group. The spicules of the ‘ beard’ are more rigid and thicker than those of Holtenia, and scattered among them are some very large four-barbed grappling hooks. car, vir] THE DEEP-SEA FAUNA. 419 Fia, 65. --Rossella velata, WyvILie THomsox. Natural size. (Mo, $2, 1870.) EE2 420 THE DEPTHS OF THE SEA. [cHar. vu. Off the Butt of the Lews, in water of 450 to 500 fathoms, we met on two occasions with full-grown specimens of a species of the remarkable genus Hyalonema (Fig. 66), with the coils in the larger examples upwards of 40 centimetres in length. Hyalonema is certainly a very striking object; and although our specimens belong apparently to the same species, H. lusitanicwm, which has already been recorded by Professor Barboza du Bocage from the coast of Portugal, it is one of the most interesting additions made to the British fauna during our cruise. A bundle of from 200 to 300 threads of trans- parent silica, glistening with a silky lustre, like the most brilliant spun-glass,—each thread from 30 to 40 centimetres long, in the middle the thickness of a knitting needle, and gradually tapering towards either end to a fine point; the whole bundle coiled like a strand of rope into a lengthened spiral, the threads of the middle and upper portions remaining compactly coiled by a permanent twist of the individual threads ; the lower part of the coil, which, when the sponge is living, is imbedded in the mud, frayed out so that the glassy threads stand separate from one another, like the bristles of a glittering brush ; the upper portion of the coil close and compact, imbedded perpen- . dicularly in a conical or cylindrical sponge; and usually part of the upper portion of the silicious coil, and part of the sponge-substance, covered with a brownish leathery coating, whose surface is studded with the polyps of an alecyonarian zoophyte : —such is the general effect of a complete specimen of Hyalonema. Fig. 66,—Hyalonema lusitanicum, Bangoza pv Bocace. Half the natural size, (No. 90. 1869, 422 THE DEPTHS OF THE SEA. [cHAP. V1. The genus was first known in Europe by specimens brought from Japan by the celebrated naturalist and traveller, Von Siebold; and Japanese examples of Hyalonema sieboldi, GRAY, may now be found more or less perfect in most of the European museums. When the first specimen of Hyalonema was brought home, the other vitreous sponges which approach it so closely in all essential points of structure were unknown, and the history of opinion as to its rela- tions is curious. The being consisted of three very distinct parts : first, and greatly the most remarkable, the coil of silicious needles; then the sponge, and for long it was supposed that this was the base of the struc- ture,—from which the glossy brush projected, spread- ing out above it in the water; and thirdly, the apparently constant encrusting zoophyte. This complicated association suggested many pos- sibilities. Was Hyalonema a natural production at all? Was it complete? Were all the three parts essentially connected together ? And if not, were all the three independent, or did two of three parts belong to the same thing? and if so, which two ? Hyalonema was first described and named in 1885 by Dr. John Edward Gray, who has since, in one or two notices in the ‘Annals of Natural History’ and elsewhere, vigorously defended the essential part of his original position. Dr. Gray associated the silicious whisp with the zoophyte, and regarded the sponge as a separate organism. He looked upon the silicious coil as the representa- tive of the horny axis of the sea-fans (Gorgonia), and the leather-like coat he regarded as its fleshy CHAP. VII.] THE DEEP-SEA FAUNA. 423 rind, He supposed that between this zoophyte and the sponge at its base, there subsisted a relation of guest and host, the zoophyte being constantly asso- ciated with the sponge; and in accordance with this view he proposed for the reception of the zoophyte a new group of alcyonarians under the name of ‘Spongicolee,’ as distinguished from the ‘Sabulicole’ (Pennatule) and the ‘ Rupicolee’ (Gorgonie), Dr. Gray’s view seemed in many respects a natural one, and it was adopted in the main by Dr. Brandt of St. Petersburg, who in 1859 published a long memoir, describing a number of specimens brought from Japan to Russia. Dr. Brandt referred what he believed to be a zoophyte consisting of the coil and the crust, to a special group of sclerobasic zoanth- carians with a silicious axis. One consideration militated strongly against this hypothesis of Dr. Gray and Professor Brandt. No known zoophyte had a purely silicious axis; and such an axis made up of loose separate spicules seemed strangely inconsistent with the harmony of the class. On the other hand, silicious spicules of all forms and sizes were conceivable in sponges ; and in 1857 Professor Milne-Edwards, on the authority of Valenciennes, who was thoroughly versed in the structure of the Gorgonie, combined the sponge with the silicious rope, and degraded the zoophyte to the rank of an encrusting parasite. Anything very strange coming from Japan is to be regarded with some distrust. The Japanese are wonderfully ingenious, and one favourite aim of their misdirected industry is the fabrication of im- possible monsters by the curious combination of the 424 THE DEPTHS OF THE SEA. [cHap. vu. parts of different animals. It was therefore quite possible that the whole thing might be an imposi- tion: that some beautiful spicules separated from an unknown organism had been twisted into a whisp by the Japanese, and then manipulated so as to have their fibres naturally bound together by the sponges and zoophytes which are doubtless rapidly developed in the Mongolian rock-pools. Ehrenberg, when he examined Hyalonema, took this view. He at once recognized the silicious strands as the spicules of a sponge quite independent of the zoophyte with which they were encrusted; but he suggested that these might have been artificially combined into the spiral coil and placed under artificial circumstances favourable to the growth of a sponge of a different species round their base. The condition in which many specimens reach Europe is certainly calculated to throw some doubt on their genuineness. It seems that the bundles of spicules made up in various ways, are largely sold as ornaments in China and Japan. The coils of spicules are often stuck upright with their upper ends in circular holes in stones. Mr. Huxley exhibited a few years ago at the Linnean Society a beautiful specimen of this kind now in the British Museum:—-a stone has been bored, probably by a colony of boring molluscs, and a whole colony of Hyalonemas, old and young, are apparently growing out of the burrows, the larger individuals more than a foot in length, and the young ones down to an inch or so, like tiny camel’s- hair pencils. All these are encrusted by the usual zoophyte, which also extends here and there over the stone (glued on probably), but there is no trace CHAP, VIl.] THE DEEP-SEA FAUNA. 425 of the sponge. Such an association is undoubtedly artificial. Dr. Bowerbank, another great sponge authority, takes yet another view. He maintains “that the silicious axis, its envelopment, and the basal sponge are all parts of the same animal.” The polyps he regards as ‘ oscula,’ forming with the coil a ‘columnar cloacal system.’ Professor Max Schultze, of Bonn, examined with great care several perfect and imperfect specimens of Hyalonema in the Museum of Leyden, and in 1860 published an elaborate description of its structure. According to Schultze, the conical sponge is the body-mass of Hyalonema, a sponge allied in every respect to Huplectella; and the siliceous coil is an appendage of the sponge formed of modified spicules. The zoophyte is of course a distinct animal altogether, and its only connection with the sponge is one of ‘commensalism,’ It ‘chums’ with the sponge for some purpose of its own,—certainly getting support from the coil, probably sharing the oxygen and organic matters carried in by the ciliary system of the sponge passages. This style of association is very common. We have another example of the same thing in Palythoa axinelle, SCHMIDT, a con- stant ‘commensal’ with Avinella cinnamomea and A. verrucosa, two Adriatic sponges. In 1864 Professor Barboza du Bocage, director of the Museum of Natural History in Lisbon, com- municated to the Zoological Society of London the unexpected news that a species of Hyalonema had been discovered off the coast of Portugal; and in 1865 he published, in the Proceedings of the same Society, 426 THE DEPTHS OF THE SEA. (cmap, vir. an additional note on the habitat of Hyalonema lusi- tanicum. It appears that the fishermen of Setubal frequently bring up on their lines, from a consider- able depth, coils of silicious threads closely resem- bling those of the Japanese species, which they even surpass in size, sometimes attaining a length of about 50 centimetres. The fishermen seem to be very familiar with them. They call them ‘sea-whips,’ but with the characteristic superstition of their class they regard all these extraneous matters as ‘ unlucky,’ and usually tear them in pieces and throw them into the water. Judging from some specimens in the British Museum, and from Senhor du Bocage’s figure, the ‘glass-rope’ of the Portuguesé form is not so thick as that of H. sieboldi. There is also some slight difference in the sculpture of the long needles, but the structure of the sponge and the very characteristic forms of the small spicules are identical in the two. I doubt if there be more than varietal distinctions between the two forms; and if that be so, it adds another to the list of species conimon to our seas and the seas of Japan. Perhaps the most singular circumstance connected with this discussion was that all this time we had been looking at the sponge upside down, and that it had never occurred to anyone to reverse it. We had probably taken this notion from the specimens stuck in stones, brought from Japan, and the sponge cer- tainly looked very like the base of the edifice. Wheu- ever the sponges were dredged on the coasts of Europe and compared with allied things, it became evident that the whisp was an organ of support passing out of the lower part of the sponge, and that the flat, ~* ouap. VIL] THE DEEP-SEA FAUNA. 427 or slightly-cupped disk, with a papilla in the centre receiving the upper end of the coil, with large oscular openings, and a fringe of delicate radiating spicules round the edge, was the top of the sponge, spreading out probably level with the surface of the ooze. In essential structure Hyalonema very closely re- sembles Holtenia, and the more characteristic forms of the Hexactinellidee. The surface of the sponge is supported by a square network, formed by the sym- metrical arrangement of the four secondary rays of five-rayed spicules, and the sarcode which binds these branches together is full of minute feathered five- rayed spicules, which project from the branches like a delicate fringe. The oscula are chiefly on the upper disk, and lead into a number of irregular passages which traverse the body of the sponge in all direc- tions. When we trace its development, the coil loses its mystery. On one of the Holtenie from the Butt of the Lews, there was a little accumulation of greenish granular matter among the fibres. On placing this under the microscope it turned out to be a number of very young sponges, scarcely out of their germ state. They were all at first sight very much alike, minute pear-shaped bodies, with a long delicate pencil of silky spicules taking the place of the pear-stalk. On closer examination, however, these little germs proved to belong to different species, each showing unmistakeably the characteristic forms of its special spicules. Most of them were the young of Tisiphonia, but among them were several Holtenie, and one or two were at once referred to Hyalonema. In two or three hauls in the same locality we got them in every subsequent stage—beautiful little 428 THE DEPTHS OF THE SEA. (cHaP. VII. pear-shaped things, a centimetre long, with a single osculum at the top, and the whisp like a small brush. At this stage the Palythoa is usually absent, but when the body of the sponge has attained 15 mm. or so in length very generally a little pink tubercle may be detected at the point of junction between the sponge body and the coil, the germ of the first polyp. Hyalonema lusitanicum, BARBozA DU Bocages, the species met with in the British seas and along the coast of western Europe, appears to be local, but very abundant at the stations where it occurs. I am still in doubt whether we are to regard it as identical with the Japanese species, H. sieboldi, Gray. During Mr. Gwyn Jeffreys’ cruise in 1870, two specimens of a wonderful sponge belonging also to the Hexactinellidee were dredged in 374 fathoms in rocky ground off Cape St. Vincent. The larger of these forms a complete vase of a very elegant form, nearly ninety centimetres in diameter at the top and about sixty in height (Fig. 67). The sponge came up folded together, and had much the appearance of a piece of coarse, greyish-coloured blanket. Its minute structure is, however, very beautiful. It consists, like Holtenia, of two netted layers, an outer and an inner, formed by the symmetrical interlacing of the four cross branches of five-rayed spicules; and, as in Holtenia and Rossella, the sarcode is full of extremely minute five and six-rayed spicules, which, however, have a thoroughly distinct character of their own, with here and there a very beautiful rosette-like spicule, another singular modification of CHAP, VII. THE DEEP-SEA FAUNA. 429 the hexradiate type characteristic of this group. Between the two netted surfaces the sponge sub- stance is formed of loose curving meshes of loosely aggregated bundles of long simple fibres, sparsely mixed with spicules of other forms. This sponge seems to live fixed to a stone. There are no anchoring spicules, and the bottom of the vase, Fic. 67.—Askonema setubalense, Kent. One-eighth the natural size. (No. 25, 1870.) which in our two specimens is a good deal con- tracted and has a square shape something like an old Irish ‘mether,’ has apparently been torn from some attachment. This fine species was named Askonema setubalense, and very briefly described from a specimen in the Lisbon Museum by Mr. Saville Kent, in a paper in which he noticed some 430 THE DEPTHS OF THE SEA. {cHar. vit of the sponges dredged from Mr. Marshall Hall’s yacht." Sponges belonging to other groups from the deep water were nearly equally interesting. I have already alluded, p. 188, to the handsome branching sponges belonging to the Esperadiz, which abound off the coasts of Scotland and Portugal. Near the mouth of the Strait of Gibraltar a number of species were taken in considerable quantity, belonging to a group which were at first confused with the Hexac- tinellide, on account of their frequently forming a similar and equally beautiful continuous network of silica, so as to assume the same resemblance tv deli- cate lace when boiled in nitric acid. The Corallio- spongie differ, however, from the Hexactinellide in one very fundamental character. While in the latter the spicule is hexradiate, in the former it consists of a shaft with three diverging rays at one end. These frequently spread in one plane, and they often re-divide, and frequently the spaces between them are filled up with a secondary expanse of silica, variously frilled and netted on the edge, so as to give the spicule the appearance of an ornamental flat-headed tack. These three-rayed stars or disks, in combination, sup- port the outer membrane of sponges of this order ; and spicules of the same type, fused together accord- ing to various plans, form the sponge skeleton. This group of sponges are as yet imperfectly known. They seem to pass into such forms as Geodia and Tethya; and the typical example with which we are most familiar is the genus Dacty- localyx, represented by the cup-shaped pumice-like 1 Monthly Microscopic Journal, November 1, 1870. CHAP. VII.] THE DEEP-SEA FAUNA. 431 masses which are thrown ashore from time to time on the West Indian Islands. Professor P. Martin Duncan has already published an account of the stony corals (the Madreporaria) of the cruise of the ‘ Porcupine’ in 1869, and he has now in hand those procured off the coast of Portugal in 1870, some of which are of even greater interest from their close resemblance to certain cretaceous forms. Twelve species of stony corals were dredged in 1869. Caryophyllia borealis, Fuemine (Fig. 4, p. 27), is very abundant at moderate depths, particularly along the west coast of Ireland, where many varieties are found. The greatest depth at which this species was dredged is 705 fathoms. Jt is found fossil in the miocene and pliocene beds of Sicily. Ceratocyathus ornatus, SEGUENZA.—Of this pretty coral only a single specimen was taken in 705 fathoms, off the Butt of the Lews. It had not pre- viously been known as a recent species, and was described by Seguenza from the Sicilian miocene tertiaries. Flabellum laciniatum, Epwarps and Hamme, was frequent in water from 100 to 400 fathoms, from Fééroe to Cape Clear. From the extreme thinness of the outer crust, this coral is excessively brittle; and although many hundreds came up in the dredge, scarcely half-a-dozen examples were entire. Another fine species of the same genus, Flabellum distinctum (Fig. 68), was dredged on several occasions off the Portuguese coast in 1570. The special interest attaching to this species, is that it appears to be identical with a form living in the seas of Japan. 432 THE DEPTHS OF THE SEA. [ewar. vit. Lophohelia prolifera, Pautas (Fig. 80, p. 169). —Many varieties; abundant at depths from 150 to 500 fathoms all along the west coasts of Scot- land and Ireland, at temperatures varying from 0° to 10° C. In some places,—as, for example, at Station 54, between Scotland and Féroe, and Station 15, between the west coast of Ireland and the Porcupine Bank,—there seem to be regular banks of it, the dredge coming up loaded with fragments, living and dead. Five allied species of the genus Amphihelia oc- curred more sparingly. Fic. 68:—Flabellum distinctum Twice the natural size. (No. 28, 1870.) Allopora oculina, EHRENBERG, a very beautiful form, of which a few specimens were procured in the ‘cold area,’ at depths a little over 300 fathoms. Thecopsammia socialis, PoURTALES (Fig. 69), a form closely allied to Balanophyllia, and resembling some crag species. It had been previously dredged by Count Pourtales in the Gulf of Florida. Theco- psammia is tolerably common in deep water in the ‘cold area,’ growing in patches, five or six examples sometimes coming up on one stone. cHAP, IX.] THE DEEP-SEA FAUNA. 433 I have already adverted to the danger we run in estimating the relative proportions in which any special groups may enter into the sum of the abyssal fauna, by the proportion in which they are recovered by any single method of capture. From their con- siderable size, the length and rigidity of their strag- gling rays, and their habit of clinging to fixed ob- jects, the Echinodermata are not very readily taken Fig. 69.—Thecopsummia socialis, PouRTALES. Once and a half the natural size. (No. 57 1869.) by the dredge, but they fall an easy prey to the ‘hempen tangles.’ It is possible that this circum- stance may to a certain extent exaggerate their apparent abundance at great depths, but we have direct evidence in the actual numbers which are brought up, that in some places they must be won- FF 434 THE DEPTHS OF THE SEA. [cuap. Ix, derfully numerous; and we frequently dredge sponges and corals actually covered with them in the atti- tudes in which they lived, nestling among their fibres and in the angles of their branches. I have counted seventy-three examples of Amphiura abyssicola, small and large, sticking to one Holtenia. Both on account of their beauty and extreme rarity, and of the important part they have borne in the fauna of some of the past periods of the earth’s history, the first order of the Echinoderms, the Crinoidea, has always had a special interest to naturalists; and, on the watch as we were for missing links which might connect the present with the past, we eagerly welcomed any indication of their presence. Crinoids were very abundant in the seas of the Silurian period; deep beds of carboniferous limestone are often formed by the accumulation of little else than their skeletons, the stem joints and cups cemented together by limy sediment; and dozens of the perfect crowns of the elegant lily- encrinite are often scattered over the surface of slabs of the muschelkalk. But during the lapse of ages the whole order seems to have been worsted in the ‘struggle for life.” They become scarce in the newer mezozoic beds, still scarcer in the tertiaries, and up to within the last few years only two living stalked crinoids were known in the seas of the present period, and these appeared to be confined to deep water in the seas of the Antilles, whence fishermen from time to time bring up muti- lated specimens on their lines. Their existence has been known for more than a century; but although many eyes have been watching for them, until very CHAP. 1x.] THE DEEP-SEA FAUNA. 435 lately not more than twenty specimens had reached Europe, and of these only two showed all the joints and plates of the skeleton, and the soft parts were lost in all. These two species belong to the genus Pentacrinus, which is well represented in the beds of the lias and oolite, and sparingly in the white chalk; and are named respectively Pentacrinus asteria, L., and P. milleri, OERSTED. Fig. 70 represents the first of these. This species has been known in Europe since the year 1755, when a specimen was brought to Paris from the island of Martinique, and described by Guettard in the Memoirs of the Royal Academy of Sciences. For the next hundred years an example turned up now and then from the Antilles. Ellis described one, now in the Hunterian Museum in Glasgow University, in the Philosophical Transactions for 1761. One or two found their way into the museums of Copenhagen, Bristol, and Paris; two into the British Museum; and one fortunately fell into the hands of the late Professor Johannes Miiller of Berlin, who published an elaborate account of it in the Transactions of the Royal Berlin Academy for 1843. Within the last few years, Mr. Damon of Weymouth, a well-known collector of natural his- tory objects, has procured several very good speci- mens, which are now lodged in the museums of Moscow, Melbourne, Liverpool, and London. Pentacrinus asteria may be taken as the type of its order; I will therefore describe it briefly. The animal consists of two well-marked portions, a stem and a head. The stem, which is often from 40 to 60 centimetres in length, consists of a series of FF2 Linnaeus, One-fourth the natural size. Fra. 70.—Pentacrinus asterta, CHAP. IX.] THE DEEP-SEA FAUNA. 437 flattened calcareous joints; it may be snapped over at the point of junction between any two of these joints, and by slipping the point of a pen-knife into the next suture a single joint may be removed entire. The joint has a hole in the centre, through which one might pass a fine needle. This hole forms part of a canal filled during life with a gelatinous nutri- ent matter which runs through the whole length of the stem, branches in a complicated way through the plates of the cup, and finally passes through the axis of each of the joints of the arms, and of the ultimate pinnules which fringe them. On the upper and lower surfaces of the stem-joint there - is a very graceful and characteristic figure of five radiating oval leaf-like spaces, each space surrounded by a border of minute alternate ridges and grooves. The ridges of the upper surface of a joint fit into the grooves of the lower surface of the joint above it; so that, though from being made up of man joints the stem admits of a certain amount of motion, that motion is very limited. As the border of each star-like figure exactly fits the border of the star above and below, the five leaflets within the border are likewise placed directly one above the other. Within these leaflets the limy matter which makes up the great bulk of the joint is more loosely arranged than it is outside, and five oval bands of strong fibres pass in the inter- spaces right through the joints, from joint to joint, from one end of the stem to the other. These fibrous bands give the column great strength. It is by no means easily broken even when dead and dry, They also, by their elasticity, admit a certain 438 THE DEPTHS OF THE SEd. [omar. 1x. amount of passive motion. There are no muscles between the joints of the stem, so that the animal does not appear to be able to move its stalk at will. It is probably only gently waved by the tides and currents, and by the movements of its own arms. In Pentacrinus asteria about every seventeenth joint of the lower mature part of the stem, is a little deeper or thicker than the others, and bears a whorl of five long tendrils or cirri. The stem is, even near the base, slightly pentagonal in section, and it becomes more markedly so towards the head. The cirri start from shallow grooves between the projecting angles of the pentagon, so that they are ranged in five straight rows up and down the stem. The cirri are made up of about thirty-six to thirty- seven short joints; they start straight out from the stem rigid and stiff, but at the end they usually curve downwards, and the last joint is sharp and clawlike. These tendrils have no true muscles: they have, however, some power of contracting round resisting objects which they touch, and there are often star-fishes and other sea animals entangled among them. The specimen figured has thus be- come the temporary abode of a very elegant species of Asteroporpa. Near the head the cirri become shorter and smaller, and their whorls closer. The reason of this is that the stem grows immediately below the head, and the cirrus-bearing joints are formed in this position, the intermediate joints being produced afterwards below and above each cirrated joint,— which they gradually separate from the one on either side of it, till the number of seventeen or eighteen CHAP. IX.] THE DEEP-SEA FAUNA. 439 intermediate joints is complete. At the top of the stem five little calcareous lumps like buttons stand out from the projecting ridges, and upon these and upon the upper part of the stem the cup which holds the viscera of the animal is placed. These buttons are of but little moment in this form, but they represent joints which are often developed into large, highly-ornamented plates in the various tribes of its fossil ancestors. They are called the ‘basal’ plates ofthe cup. Next, in an upper tier, alternating with the last, we have a row of five oblong plates opposite the grooves of the stem, and all cemented into a ring. These plates are separate when the animal is young; they are called the ‘first radial’ plates. They are the first of long chains of joints which are continued to the ends of the arms. Imme- diately above these plates, and resting upon them, there is a second row of plates nearly of the same size and shape, only they remain separate from one another, never uniting into a ring. These are the ‘second radials,’ and immediately upon these rest a third series of five, very like the plates of the other two rows, only their upper surfaces rise into a cross ridge in the centre, and they have the two sides bevelled off like the eaves of a gable, to admit of two joints being seated upon each of them instead of one. This last ring of joints are the ‘radial axillaries,’ and above these we have the first bifurcation of the arms. These three rings of radial joints form the true cup. In the modern species they are very small, but in many fossils they acquire a large size, and enclose, frequently with the aid of various rows of intermediate or 440 THE DEPTHS OF THE SEA. [cHAP. Ix. inter-radial plates and a row of basals, a large body-cavity. The two upper joints of each ray are separated from: those of the ray next it by a prolongation downwards of the plated skin which covers the upper surface or ‘disk’ of the body. Seated upon the bevelled sides of each radial-axil- lary joint, there is a series of five joints, the last of the five bevelled again like the radial axillaries for the insertion of two joints. These five joints form the first series of ‘ brachials,’ and from the base of this series the arms become free. The first of the brachial joints, that is to say, the joint immediately above the radial axillary, is, as it were, split in two by a peculiar kind of joint, called, by Miller, a ‘syzygy.’ All the ordinary joints of the arms are provided with muscles producing various motions, and binding the joints firmly together. The syzygies are not so provided, and the arms are consequently easily snapped across where these occur. This is a beautiful provision for the safety of an animal which has so wide and complicated a crown of appendages. If one of the arms get entangled, or fall into the jaws or claws of an enemy, by a jerk the star-fish can at once get rid of the embarrassed arm; and as all this group have a wonderful power of reproducing lost parts, the arm is soon restored. When the animal is dying, it generally breaks off its arms at these syzygies; so that almost all the specimens which have been brought to Europe have arrived with the arms separate from the body. About six arm-joints or so above the first on either branch there is a second brachial accessory and CHAP. Ix.] THE DEEP-SEA FAUNA. 44] another bifurcation, and seven or eight joints farther on another, and so on, but more irregularly the farther from the centre, till each of the five primary rays has divided into from twenty to thirty ultimate branches, producing a rich crown of more than a hundred arms. The upper surface of each arm-joint is deeply grooved, the lower arched; and from one side of each, alternately on either side of the arm, there springs a series of flattened ossicles. These form the ultimate branchlets, or ‘ pinnules,’ which fringe the arms as the barbs fringe the shaft of a feather. Unfortunately, most of the examples of Pentacrinus asteria hitherto procured have had the soft parts destroyed and the disk more or less injured. One specimen, however, in my possession is quite perfect. The body is covered above by a membrane closely tesselated with irregularly-formed flat plates; this membrane, after covering the disk, dips into the spaces between the series of radial joints, and with the joints of the cup completes the body-wall. The mouth is a rounded opening of considerable size in the centre of the disk, and opens into a stomach passing into a short curved intestine which ends in a long excretory tube,—the so-called ‘proboscis’ of the fossil crinoids,—which rises from the surface of the disk near the mouth. From the mouth five deep grooves, bordered on either side by small square plates, run out to the edge of the disk, and are con- tinuous with the grooves on the upper surface of the arms and pinnules, while in the angles between them five thickened masses of the mailing of the disk surround the mouth like valves. These were at first supposed to answer the purpose of teeth. The 442 THE DEPTHS OF THE SEA. (CHAP. IX, crinoids, however, are not predatory animals. Their nutrition is effected in a very gentle manner. The grooves of the pinnules and arms are richly ciliated. The crinoid expands its arms like the petals of a full- blown flower, and a current of sea-water bearing organic matter in solution and suspension is carried by the cilia along the brachial and radial grooves to the mouth. In the stomach and intestine the water is exhausted of assimilable matter, and the length and direction of the excretory proboscis pre- vent the exhausted water from returning at once into the ciliated passages. The other West Indian Pentacrinus—P. Milleri— seems to be more common off the Danish Islands than P. asteria. The animal is more delicate in form. The stem attains nearly the same height, but is more slender. The rings of cirri occur about every twelfth joint, and at each whorl two stem- joints are modified. The upper joint bears the facet for the insertion of the cirrus, and the second is grooved to receive its thick basal portion, which bends downwards for a little way closely adpressed to the stem, before becoming free. The syzygy is between the two modified joints, and in all the com- plete specimens which I have seen the stem is broken through at one of these stem syzygies, and the ter- minal stem-joint is worn and absorbed, showing that the animal must have been for long free from any attachment to the ground. On the 21st of July, 1870, Mr. Gwyn Jeffreys, dredging from the ‘ Porcupine’ at a depth of 1,095 fathoms, lat. 39° 42’ N., long. 9° 43’ W., with a bottom temperature of 4°°3 C. and a bottom of soft Pir 71 —Pentacrinus wyville-thomsoni, JEFFREYS. Natural size. (No. 17, 1870.) - 444 THE DEPTHS OF THE SEA. [cwap. 1x, mud, took about twenty specimens of a handsome Pentacrinus involved in the ‘hempen tangles ;’ and this splendid addition to the fauna of the European seas my friend has done me the honour to associate with my name. Pentacrinus wyville-thomsoni, JEVFREYS (Fig. 71), is intermediate in some of its characters between P. asteria and P. miilleri; it approaches the latter species, however, the more nearly. In a mature specimen the stem is about 120 mm. in length, and consists of five or six internodes. The whorls of cirri towards the lower part of the stem are 40 mm. apart, and the in- ternodes contain from thirty to thirty-five joints. The cirri are rather short and stand straight out from the nodal joint, or curve sharply downwards, as in P. asteria. The nodal joint is single, and the syzygy separates it from the joint immediately beneath it, which does not differ materially from the ordinary internodal stem-joint. All the stems of mature examples of this species end uniformly in a nodal joint, surrounded with its whorl of cirri, which curve downwards into a kind of grappling root. The lower surface of the terminal joint is in all smoothed and rounded, evidently by absorption, showing that the animal had for long been free. This character I bave remarked as occurring in some specimens of P. milleri. I have no doubt that it is constant in the present species, and that the animal lives loosely rooted in the soft mud, and can change its place at pleasure by swimming with its pinnated arms; that it is in fact intermediate in this respect between the free genus Antedon and the permanently fixed crinoids. cua. 1x.] THE DEEP-SEA FAUNA. 445 A young specimen of P. wyville-thomsoni gives the mode in which this freedom is acquired. The total length of this specimen is 95 mm., of which the head occupies 85 mm. The stem is broken off in the middle of the eighth internode from the head. The lowest complete internode consists of 14 joints, the next of 18, the next of 20, and the next of 26 joints. There are 8 joints in the cirri of the lowest whorl, 10 in those of the second, 12 in those of the third, and 14 in those of the fourth. This is the reverse of the condition in adult specimens, in all of which the numbers of joints in the internodes, and of joints in the cirri, decrease regularly from below upwards. The broken internode in the young example, and the three internodes above it, are atrophied and un- developed, and suddenly at the third node from the head the stem increases in thickness, and looks as if it were fully nourished. There can be no doubt that in early life the crinoid is attached, and that it becomes disengaged by the withering of the lower part of the stem. The structure of the cup is the same as in P. asteria and P. miillert. The basals appear in the form of shield-like projections crowning the salient angles of the stem. Alternating with these we have well-developed first radials, forming a closed ring and articulating to free second radials by muscular joints. The second radials are united by a syzygy to the radial axillaries, which as usual give off each two first brachials from their bevelled sides. i ae Rhetic | A London Upper Lower and Per- Carbo- , Atlantic.) Crag. | * clay, Chalk. | Jurassic. | Jurassic. | Upper mian. | niferous. | - Trias. |---| = no | 53 | 38 | 19 7 i Fi || ; | \ 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 Paulie 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 circumstance 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 BNE ge viene . . 133 Sesquioxide of iron (‘soluble in acids’) . , . 2°17 Silica (in a soluble condition). . . . . . 5:04 Fine insoluble oa sand (rock doris) nas 26°77 Water . . . . « 290 Organic matter . . . : age GLO Chloride of sodium and other ‘sotuble 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 careful 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 SEA. [cAP. 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 } 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 FarHoms (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 Fkom 1,476 Farnoms (Srarion 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. [cuar. 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 CHALE. 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 cS - ne »0 ; 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 portions 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 pene, 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. eens atlantica—A. ornata, Amphiura abyssicola, 123. Antedon celticus, 76; A. escrichtii—A. sarstz, 124, Aphrocallistes bocaget, 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 haeckelit, 412. Bathycrinus gracilis, 450, 453, Bathyptilum carpenteri, 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. Calveria 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, 378 ; 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. Choanttes, 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 tubifer, 485. 524 Coralline Zone, 16. Crinoidea, 434. oo James, ou ocean currents, 376, 1. D. Dacrydium vitrewm, 465. Darwin, Charles, M.A., F.R.S., ‘ Origin of Species,’ 8. ae 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, 309-325, Depth of the Sea, 1; first successful dredgings at great depths, 3; animal forms found 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 thomsoni, 174. Dredging Apparatus: Miiller’s dredge, 239 ; 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- are angulatus, 117, 459; Echino- thuride, wide distribution of, 171; Lichinus elegans, 76, 459; £. escu- lentus, 458 ; E. flemingii, 116, 458; L. melo, 459; H. microstoma, 171, 459; EE. 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, 130. 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 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. evlepiae rhombotdes, 87. oodsir, Henry, deep dredging in Davis’ Strait, yi ue - oe Gray, Dr. John Edward, F.R.S., on Hyalonema, 422. Gulf-stream, 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, 4298; H. lusitanicum, 420, 421; 4. 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 ing 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 tae the depth of 1,100 fathoms, Mohn, Professor H., on surface and deep- sea temperatures on the west coast of Norway, 396. as 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’ or 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. ae purpurea, 123; 0. glacialis, 526 Ophiothrix littkent, 100. Orbitolites tenuissimus, 91, 194. Orbulina undversa, 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. ee 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 ; Holte- 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-ffreyst, 103, 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 microtuberculatus, 457 ; P. miliaris, 459 Psolus syuamatus, 125. Preraster 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 soundings 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, cla raschi, 118; S. purpureus, Spirorbis, 273. 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. T. Tanks for the transportation of living fish, 59. Tellina calcaren, 462; T. compressa, 464. Ber porate of the crust of the earth, Terebratula septata, 130. Pleeophett: semisuberites, 147; T. bla, 148. Thecopsanumia 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 MaruHE- matics; Pxysics, Astronomy, GEOLOGY, Creurstey, Zootocy, Botany; Pxystotocy Anatomy and Mepicat Works generally ; and of Works tn Menrar and Morar Puitosoruy 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. 9s. 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 ; Lixperiments 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 authors 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 is 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 illustrations, 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 problens 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.—Works 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. TODHUNTER. 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. ros. 6d. New Edition revised. 1 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 work is in some measure designed as a sequel to Professor Boole's Treatise on Differential Equations. MATHEMATICS. ae 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 ua 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 especially 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,—PROBLEMs AND RIDERS. By Campion and WALTON. 8vo. cloth. 85. 6d. 1860.—PROBLEMS AND RIDERS. By Warson and RoutH. 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. Cuevye, 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 geometrical 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 jirst 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, Oxiord. Small 4to. cloth. tos. 6d. MATHEMATICS. 7 The object of the author ts 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. Frrrers, 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, it 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 fluid—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. vo. 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 thts complete edition of Newton's Principia that tt 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 presumed 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. 7s. 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.—AaN ELEMENTARY TREATISE ON THE DYNA- MICS OF THE SYSTEM OF RIGID BODIES. With numerous Examples. By EDwarD JoHN RoutTH, 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. Snowspar1t, 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 tn 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. STrzLE. 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. 6d. 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 is 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. Ios. 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 Lxamples 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, wiul the rich stove 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. 45. 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 subtle 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 Examiners :—‘‘A determination of the circumstances under which discontinuity of any kind presents itself in the solution of a problem of maximum or minimum 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 discontinuous 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 improvement 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. 6d. 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” is fully considered. “* He has made a notable contribution to the literature of scientific research and exposition.”—Daily News. “ft is a book that 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 immense eastec 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 between them. He then endeavours to trace out the main consequences of the fundamental 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 IM. 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 is 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. "93 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 Wiiuram 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 intelligible 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 is 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. 9s. 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 Governments and scientific bodies would 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, Meteore- 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 men, 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- stons.” 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. NorMAN 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 is 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 Mr. 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).—LAay 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 Irish 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 is 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. V. Motion of a Solid Body. VI. Necessary and Possible Equilibrium. WTI. 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. Roscor, 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 = 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 aim 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. 59. “ Those who have derived pleasure and profit from the study of flowers and ferns—suljects, it is 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. GEorGE 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 primeval cosmos, ‘in the beginning,” by its Creator, its Upholder, and its Lord. Nearly fifty woodcuts wlustrate 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, £.R.S., @ 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, Is. 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 Journal, 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 DANIEL OLIVER, F.R.S., F.L.S., 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 summary of all essential 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 endeavotired 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 JonEs, Chemical Master in the Grammar School, Manchester. 18mo. with Illustrations, 25. 67. 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 Nebulae. New Edition. 18mo. 45. 6d. A description, in an elementary manner, 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 cere 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 Ginology. 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 complete 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. 8s. 6d. (For other Works by-the same Author, see CaTa- LOGUE OF HisTORY AND TRAVELS.) Mr. 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.” II. ‘‘ On the Tendencies of Varieties to depart indefinitely from the Original Type.’ IIT, “‘Ali- micry, and other Protective Resemblances among Animals.” TI). ‘* 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. ; i) Warington.—THE WEEK OF CREATION; OR, THE COSMOGONY OF GENESIS CONSIDERED IN ITS RELATION TO MODERN SCIENCE. By GrorcE 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.—wWorks by the late Gzorcr 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 sii 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 Je eduael 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 occurred 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.” XI. *‘ 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. I5s. 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 authors 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 é 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.) 2s. 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. Lhe 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 RicHarp 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. fle 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.)—Aa 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.” VIIT. ‘Value of Sewage; Injury to Rivers.” IX. “Town Sewage; Attempts at Utilization.” X. “Filtration and Trrigation.” 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 work 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.” These 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 DraGNnosis 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. Ln 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 trritation or by septic matters. This method of inquiry 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. ix 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 Fames 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 JoHN 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, inipres- 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 for a 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 ain 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. Futton’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. Humpury, 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 information forms, in 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. 6d. 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 node 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 MacrHerson, 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, 1t 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. Ill. 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. PPp- xv. 205. 35. Oe. . 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.