July 2, 1874] 



NA TURE 



171 



gave of the Cltallen^cr observations in the Atheiiceum of 

 May 16. 



As I have never claimed any originality in regard to 

 the doctrine of oceanic circulation, which I have advo- 

 cated solely as an important scientific truth, it has 

 afforded me nothing but tlie most unalloyed satisfaction 

 to find that the doctrine which appeared to me, as to Sir 

 John Herschcl (when I brought the case fully before 

 him), the " common sense of the matter," was put forward 

 nearly thirty years ago by one of the most eminent phy- 

 sicists of his day, as a necessary deduction from the facts 

 of observation. That Lenz's Doctrine of Oceanic Circu- 

 lation (for so it should now be termed) did not then obtain 

 the general acceptance which I now confidently anticipate 

 for it, seems principally due to the little attention formerly 

 paid to Ocean Physics ; it being only in recent years that 

 the relation of deep-sea temperatures to the distribution 

 of animal life on the ocean bottom, and the consequent 

 importance of this knowledge in ideological research, has 

 made the inquiry one of general interest. This is the point 

 of view in which the study of the subject has been 

 pursued by Mr. Prestwich, whose exhaustive memoir will 

 constitute a most valuable preface to the full discussion of 

 the Chalhiigcr observations, when these shall have been 

 brought to a conclusion two or three years hence. 



" The mass of water in the tropics," says Lenz, "warmed 

 down to a certain depth by the sun's heat, cannot main- 

 tain its equilibrium with the colder water of the middle 

 and higher latitudes ; a flow of the warmer water from 

 the equator to the poles must necessarily take place on 

 the surface, and this surface-flow must be supplied at the 

 equator by a flow of colder water from high latitudes, 

 which would at first flow in an almost horizontal 

 direction, but which under the equator must rise from 

 below to the surface. In this manner, in the northern 

 hemisphere, a great vertical circulation takes place in the 

 ocean, which has its direction above from the equator to 

 the pole, and below from the pole to the equator. .Since 

 these flows, moving in opposite directions, are distin- 

 guished by their different temperatures, we observe in the 

 submarine isotherm an indication of the lower portion of 

 this flow. A corresponding flow, but moving in the op- 

 posite direction, takes place in the southern hemisphere ; 

 so that in a ::oiic surrounding the equator, lohere the two 

 /lows meet, the water flows almost in the direction from 

 belo'ii) up to the surface" 



Lenz further adduced the ld>.- salinity of the surface- 

 water of the equatorial belt, con, pared with the high 

 salinity of tropical water, as an additional indication of 

 the continual ascent of polar water from the bottom. And 

 after remarking that water moving in the north and south 

 direction must have its course influenced by the rotation 

 of the earlh, he continues, "It is a point which has been 

 determined by Humboldt, John Davy, and others, that 

 the water of the ocean is colder at the surface over shal- 

 lows, than at some distance beneath over very great 

 depths. This phenomenon, the explanation of which 

 hitherto has not been found to be satisfactory, is a simple 

 consequence of the movement of deep cold water from 

 the pole to the equator. For if this runs against any ob- 

 struction, such as a shallow would present, it will rise 

 along it, as upon an inclined plane, and approach nearer 

 the surface, which in this manner will be cooled down." 

 Thus Lenz explicitly propounded the principle on which I 

 have explained the " cold band " between the Gulf Stream 

 and the United States sea-board, the similar cold band 

 on the cast coast of Japan, and the cold stratum on the 

 east side of the Dogger Bank. And I venture to believe, 

 therefore, that here, too, the "common sense of the 

 matter " has led me to a right conclusion. 



1 learn also, from Mr. Prestwich's memoir, that Arago, 

 in 183S, in his instructions for a scientific expedition to 

 Africa, not only distinctly recognised the existence of an 

 underflow of glacial water from the poles towards the 



equator as the cause of the reduction of oceanic tempera- 

 ture with depth, and explicitly repudiated the doctrine of the 

 uniform deep-sea temperature of 39.!' ; but also remarked 

 upon the comparatively high temperature of the deeper 

 stratum of the Mediterranean (first ascertained by 

 D'Urville) as indicating that the polar flow does not find 

 its way into that basin through the Strait of Gibraltar ; 

 thus anticipating the argument which I have based 

 on my own investigations into the comparative thermal 

 conditions of the Atlantic and the Mediterranean, as to 

 the existence of a polar underflow in the former. 



WiLLiAii B. Carpenter 



NOTES 



We greatly regret to announce that Prof. Angstrom died on 

 the 2 1 St ult. 



Mr. Joseph Prestwich, F.R.S., F.G.S., has been ap< 

 pointed to the office of Professor of Geology in the University 

 of 0.\ford, as successor to the late Prof. Phillips. 



The Chair of Human Physiology in University College, 

 London, in future to be called the Jodrell Professorship, after 

 the name of its endower, has been filled by the appointment of 

 Dr. J. Burdon Sanderson, F.R.S., who is now Professor of 

 Physiology, including Practical Physiology and Histology. We 

 have reason to believe that Mr. E. A. Schiifer will be appointed 

 Assistant Professor under Dr. Sanderson. 



M. A. de Candolle has been elected a Foreign Associate 

 of the French Academy in the place of the late Prof. Agassiz. 



The death, at the eady age of 28, is announced of Mr. Charles 

 Tyrwhitt Drake, one of the ofificers in charge of the survey of 

 Palestine. He succumbed to a second attack of malarious 

 fever. 



Entomologists generally, and Coleopterists in particular, 

 have experienced a great loss in the death of Mr. George Robert 

 Crotch, M.A., of St. John's College, Cambridge. Mr. Crotch 

 graduated in 1S63, obtaining honours in the Natural Science 

 Tripos. Until 1872 he was one of the Under Librarians 

 at the University Library, when, besides his excellent work 

 in that Institution, lie devoted his spare time to his favour- 

 ite subject. Mr. Crotch sailed for America in 1872, cit route 

 for Australia, for the purpose of studying the entomology of 

 parts which he considered incompletely known, and on several 

 occasions he has transmitted collections to England. He had 

 added considerably to our knowledge of the entomology of 

 California, Vancouver's Island, Oregon, and other districts ; 

 and on two occasions the Senate of Cambridge, recognising the 

 importance of his work, voted him a sum of money from the 

 University chest to aid him in sending collections to the Uni- 

 versity Museum. 



Two scientific expeditions are to set out from Archangel next 

 summer— one into Russian Lapland, for the purpose of exploring 

 the traces of ancient glaciers ; the other, to the shores of the 

 White Sea, has for its object zoological investigations. Dr. 

 Varjinsky, Ln Revue Scieiitifique states, who explored the district 

 two years ago, discovered in the White Sea and the glacial ocean 

 fishes and crustaceans till then quite unknown. 



Mr. James Lick, of San Francisco, Califomia, having in 

 the course of his life accumulated a large fortune, has recently 

 concluded a deed by which he conveys all his property to seven 

 persons upon trust to be applied lo various worthy objects. 

 Among these, 700,000 dols. are to be app'ied to the construc- 

 tion of a more powerful telescope than any yet mide, to be 

 erected at an observatory in California, and 300,000 dols. to 

 found, in Califomia, a school of the mechamVal arts. 



