Oct. 27, 1881] 



NATURE 



613 



proviace, to notorious for its turbulent braves, whose hostility to 

 foreigners is proverbial. Mr. Dorwai-d has however established 

 the fact that a European, with tno native assistants, can now 

 traverse the province in safety. Near the city of Shenchi, some 

 450 miles from Wuchang, he had an opportunity of observing 

 the processes used for extracting gold-dust from the sand, which 

 consist in roughly sifting and afterwards using quicksilver. 



The Argentine Government has just despatched two officials 

 to survey five thousand square leagues of country in the neigh- 

 bourhood of the Neuquem, one of the chief tributaries of the Kio 

 Negro. This extensive tract of country is close to the Andes, 

 and is said to be extremely fertile. When the survey is com- 

 pleted the Government will dispose of the land with a view to its 

 early colonisation. 



The Commercial Geogra])hical Society of Bordeaux in its 

 last Bulletin publishes a useful topographical note on the itinerary 

 followed by the Upper NigerSurveying Expedition fiom Kita 

 to Baniaku. 



The Department of the Interior in Canada has issued a new 

 map of Manitoba and the North- West Territories, showing the 

 country surveyed, &c., and in a later edition the line of the 

 Canadian Pacific Railway will be shown. 



We he.ir that the Depot de la Guerre at Paris has just issued 

 the first sheet of Col. Perrier's map of Tunis, drawn from his 

 recent topographical survey of the country, which has been 

 awaited with much impatience by French geographers. 



PiRE DuPARQUET, the well-known missionary traveller, who 

 returned to South- West Africa early in October, has recently 

 commenced the publication, in Les Alissions Calholiques, of an 

 account of a joiu'ney made by him throngh Ovampo Land as far 

 -.5 the Kiver Cunene. He travelled in company with Mr. 

 "rchison, one of the principal traders of Omaruru, who also 

 ad with him a son of the late Mr. C. J. Anderson. Pere 

 Juparquet's memoir is illustrated by a sketch-map of the region, 

 on which is shown a singular connection between the River 

 Cunene and Lake Etosha. 



In the new number (Heft 3, Band 4) of the Deutsche geo- 

 graphische Blatter, all the existing information on Wrangel Land 

 and Herald Island has been collected, and will be of interest at 

 present in connection with the missing yeaitnette. Dr. Albrecht 

 Penck of Munich contributes an interesting article on glaciation 

 with special reference to Eschscholtz Bay in Kotzebue Sound 

 on the rorth-west coast of America ; and Herr G. Kreitner 

 gives a detailed account of the Koko Nor and the surrounding 

 region. There are besides a variety of notes on various points 

 of geographical interest. 



To the Austrian Monatsschrift fur den Orient for October, M. 

 Z. Janiczek of Port Said contributes a letter containing a good 

 deal of valuable information on the trade of the Red Sea. In a 

 letter from Herr Hansel of Khartoum v\e find some interesting 

 information from Dr. Emin Bey. Among other things he tells 

 us that there are three lakes to the north of Victoria Nyanza ; 

 that Beatrice Gulf certainly does not belong to Albert Nyanza, 

 but to a lake lying from the south ; that steamers now go regu- 

 larly from Dufile to Mahagi, a station on the west coast of 

 Lake Albert ; and that the only radical cure for the Central 

 African slave-trade is the importation of free Chinese colonists. 

 Prof. Blumentritt contrihu'es notes on some important vegetable 

 products and branches of industry in the Philippine Islands. 



Heft i, for 1880-1, of the Mittheihingen of the Hamburg 

 Geographical Society contains a paper of great interest on the 

 distribution and relative value of cowrie shells by Herr John E. 

 Hertz. These shells are used as money mainly in the region 

 between the Niger and the coast of Africa, though they are also 

 in use in other parts of the world. Herr Hertz gives the ex- 

 change value of these shells in the various regions where they 

 are used, and traces their hi tory as a trading medium. A kin- 

 dred jiaper, of much practical value and considerable interest, is 

 on the barter-trade of Afiica, by A. Wormann. A long paper, 

 with chart, en the yaihs I'f barometric minima in Europe and 

 on the North Atlantic, and their influence on wind and weather 

 in North Germany, by Dr. W. Kbppen, is of considerable scien- 

 tific interest. There is also a lecture by Dr. J. Classen on a visit 

 to Olympia. 



According to the latest census the population of Japan on 

 January i, 18S0, was 35,925,313. Of these 18,210,500 were 

 males, and 17,714,813 females. When the numerous and de- 



structive civil v\ars of the last twenty years are remembered, ihi 

 relative proportion of the sexes will appear striking. Writers of 

 the last century held very exaggerated notions of the population 

 of Japanese ton ns, but the present census shows that some of 

 them may properly rank among the most populous cities in the 

 world. To kio and its environs has a population of 957,121 ; 

 Kioto, the old capital, of 822,098 ; and Osaka, 582,668. The 

 smallest population of any district is that of the Bonin Islands, 

 recently annexed to Japan, which contain only 156 inhabitants, 

 composed of officials and descendants of Kanakas and deserters 

 from English and American whaling ves els. 



Capt. John Mackay, of the ss. Southern Cross (Auckland), 

 sends us, along with a note, an account by himself in the 

 Qut-enslanJer of his cKscovery and settlement of the di-trict of 

 Mackay in Queensland. To the now flourishing town of Mackay 

 we referred some time ago in connection with a special number 

 of the Maikay Standard. The town bids fair to become one of 

 the most flourishing in Queensland, though its di^coverer does 

 not seem to have met with the lecognition he deserves. 



SOLAR PHYSICS ' 

 II. 



AT the conclusion of my last lecture I stated my be ief that 

 tho.se changes which are continually going on at the surface 

 of the sun had their origin in currents of convection, and I 

 illustrated the processes which are there going on by what we 

 know to be going on on the surface of our own earth. I re- 

 ferred, but only historically, to a theory w hich was thrown out 

 many years ago as to the origin of solar heat by Sir William 

 Thomson, according to which it depended on the impact of 

 meteoric bodies. I did not suppose at the time that he still 

 retained that theory, regarding it as the most probable ; in fact 

 he gave it up many yeai-s ago, and I was glad to find, from 

 conversation with him after the lecture, he is quite of the same 

 opinion as I am, that these disturliances — the enormous disturb- 

 ances which take place at the .surface of the sun, have their 

 origin in currents of convection. I stated my belief that the 

 spots were produced by the downward rush of, comparatively 

 speaking, cool portions of gas which had been in the first 

 instance ejected during these eruption^. In speaking to Mr. 

 Lockyer afterw ards I found that he had obtained independent 

 evidence from his spectroscopic re.-earches that these spots con- 

 sisted of down-nishes of ga^, and not, as some have supposed, 

 of up-rushes. He may have mentioned it to me before ; if so 

 I must apologise for it having passed from my memory. I will 

 not however say anything al)out the evidence on which he w as 

 led to that conclusion, because he is going to lecture himself, 

 and of course he will be the proper person to explain his own 

 discoveries. 



Now with regard to these spots I have hitherto said r.othing 

 except as to their existence. The German astronomer Schwabe 

 assiduously observed them in the beginning of 1826, and for 

 about a quarter of a century he went on constantly observing 

 ihem and making careful drawings of them. As the result of 

 this long-continued and careful work, he was led to the conclu- 

 sion that these -pots as to their frequency and magnitude appear 

 to lie subject to a periodical inequality. The period appeared to 

 be about ten years, during which, supposing you start with the 

 m.iximum of spots, they dwindle away to the minimum, then 

 after some years again rise afresh, and by the end of ten years 

 or thereabouts you get to the maximum. M. Wolf of Berne 

 has discussed the subject, and referred back to older obser\ations, 

 and was led to the conclusion that the 1 eriod was longer than 

 ten yeai's. He makes it eleven years, or perhaps more exactly 

 nine periods per century. 



I H ill now come to some phenomena observed on the earth 

 with w hich the solar spots w ould. at first sight, appear to have 

 no possible connection. You are all, of course, familiar with 

 the magnetism of the earth, by the aid of which our ships are 

 navigated through the ocean. Now it has been long known that 

 the magnetic needle is subject to disturbance ; by the magnetic 

 needle I mean the magnet suspended so as to turn freely round 

 a vertical .axis. For a long time after the tliscovery of mag- 

 netism that was the only kind of instrument used for the 

 observ.ition, and it had been observed that these disturbances 

 were of two kinds. There was a regular diurnal movement of 

 the needle to the west, and then to the east, of its mean position, 



' Lecture by Prof. Stokes, Sec.R.S., in the South Kensington Museum 

 Theatre, continued from p. 508. 



