June 29, 1882] 



NA TURE 



21 1 



way or other its action and its existence traceable to the sun. 

 That there was an unlimited supply of energy in Ihe interior of 

 the earth was a circumslance which had, he said, been over- 

 looked. In speaking of this energy, Mr. Milne first referred to 

 that portion of it which crops out upon the surface in countries 

 like Japan, Iceland, and New Zealand, in the form of hot 

 springs, solfataras, volcanoes, &c. He stated that there was an 

 unlimited supply of water in hot springs within a radius of one 

 hundred miles around Tokio, and that the heat of these springs 

 could be converted into an electric current, and the energy trans- 

 mitted to the town. The second part of the paper referred to 

 the possibility of obtaining access to the heat which did not crop 

 out in the surface. 



The whole" behaviour of homogeneous colours is explained 

 (according to Herr Albeit, U'icJ. Ann., No. 5), on the Young- 

 Helmholtz theory, by this assumption : To a lessening of the 

 intensity of vari-coloured light correspond various lessening of 

 the strength of sensation, such that for rays of less wave-length, 

 to whatever part of the spectrum they belong, it decreases more 

 slowly than for rays of greater wave-length. 



GEOGRAPHY IN RUSSIA 



T 



HE just issued "Annual Report of the Russian Geographical 

 Society for 1S81 " shows that during last year the Society has 

 again accomplished agood deal of useful scientific work. Asub- 

 ject !o which much attention was given was the establishment of 

 polar meteorological stations. The station at Novaya Zemlya 

 has already been in operation, as is known, for two years, and a 

 new one, which will be established at the mouth of the Lena, is 

 provided with the best instruments, and is intrusted to persons 

 who will be able to make of it a first-class meteorological obser- 

 vatory. During the summer the expedition will reach the shores 

 of the Arctic Ocean, and begin the meteorological observations. 

 The Dutch station will be erected at Port Dickson, at the mouth 

 of the Yenisei. 



Among the scientific expeditions undertaken by the Society, that 

 ofM.Polakoff, to Sakhalin, promises to give very interesting results. 

 The rich ornithological collections made in the Alexandrovsk Yal- 

 ley, on the western coast, proved that the birds of Western Sakhalin 

 have a remarkable likeness with those of Siberia and Northern 

 Russia. The same is true with regard to the former inhabitants 

 of Sakhalin, whose stone implements and remains of earthenware, 

 discovered in great masses, are much like, or even identical to, 

 those of European Russia ; the presence of obsidian implements, 

 however, originally from Kamschatka, or from the islands of 

 the Pacific, hints that the inhabitants were in intercourse with 

 these countries. M. Polakkoff has also discovered dwellings of 

 the same period, which were holes, like those of the Kamtcha- 

 dales, the numerous stone pieces which were used to be attached 

 to the net=, show that the nets of the prehistoric man were very 

 large, and that fishing was carried on to a great extent at that 

 period. 



The re.-ult of M. Polakoft's explorations of the eastern shores 

 of the island, as well as in its middle parts, are not yet known. 

 M. Adrianoff's journey in very little known parts of the Tormsk 

 and Sayan Mountains, during which the explorer crossed Lake 

 Teletzekoye and the Shapshal Mountains, have given rich 

 materials for the geology, z iol< gy, and botany of these coun- 

 tries. The travels of A. E. Regel to the Pamir, M. Hedroitz's 

 explorations of the alluvial deposits of the Amu-daria, M. Lessar's 

 travel to Saraks, and M. Moushketoff's researches en Cauea-u--, 

 have already been mentioned in NATURE. 



A very interesting journey, mentioned in the "Report," was 

 made by A. YV. Eliseeff, who tried to follow the same route to 

 Palestine which was followed by the Jews during their exode 

 from Egypt. M. Eliseeff discovered during the journey numerous 

 traces of man of the Palaeolithic and of the Neolithic periods in 

 Arab:a Petrea, as well as in Egypt and in Palestine. The pre- 

 historic man of the Sinai peninsula belonged to two different 

 types : one, with light bones, of the Semitic type, and the other, 

 with massive bones, of the Berber type; dolichocephalic skulls 

 are predominant. Both had the custom of burning corpses, and 

 did not neglect anthropophagy ; however, their chief food con- 

 sisted of wild animals, fishes, and molluscs. The disposition of 

 these remains confirms the hypothesis of Owen, that the Sinai 

 peninsular and lower Egypt were under water, excepting the 

 higher terraces, after man inhabited the banks of the Nile. As 

 to the present inhabitants, the Arabs of the peninsula afford two 

 different types : a western one, more akin to the Fellah and 



Egyptian type, and the eastern one, which is of a purer Arabian 

 origin. The nomad Bedouins belong to different sub-types, and 

 there are in the Bedouin desert, traces of a fair-haired people, 

 as well as representatives of Berberian and Ethiopian blood. 

 Some very interesting material for a knowledge of prehistoric 

 man w as also discovered by M. W. Malakhoff. during his journey 

 on the western slopes of the Middle Ural. The remains of this 

 epoch are very numerous, especially on the shores of lakes, and 

 they are the more interesting, as we find here the first vestiges 

 of an epoch when the Neolithic man began to discover the 

 properties of metals, and to manufacture metallic implements 

 from the rich ores he found on the Ural. The skele- 

 tons of men of this period discovered, together with mixed 

 implements of stone, bone, and copper, are most interesting, 

 especially w ith regard to the skulls, which represent a very low 

 stage of human development. The remains of a later epech 

 (implements and rock hieroglyphics) are also very numerous. 

 M. Malakhoff concluded his researches by ethnographical ob- 

 servations on the present Permyaks, whom he considers as very 

 nearly akin to the primary prehistoric inhabitants of this region. 

 G. N. Potanin's exploration of the Votyaks, of their migrations, 

 mythology, and customs, and an excursion of S. K. Kouznetzoff 

 to the Tcherenisses of the Vyatka government promises to yield 

 interesting results. 



Among the new publ'cations of the Society we notice the 

 following : — The Anthropology of Mordvinians, by \V. N. 

 Mairoff, is printing, and will appear in the eleventh volume of 

 the Ethnographical Memoirs of the Society; the anthropological 

 researches of K. S. Mereshkovsky in the Crimea, preliminary 

 reports of which have appeared in the Izvestia, will soon be 

 ready to print ; G. N. Potanin's work, " Sketches of North- 

 western Mongol's," being a report, in two volumes, of his first 

 journey in Mongolia, is an important acquisition for the 

 geography of Asia ; the first volume contains abundance of 

 valuable geographical information, and the second contains the 

 ethnographical results, with twenty-six tables of drawings. 

 Volumes iii. and iv. of this work, the third already being under 

 pre s, will contain the results of the second journey of M. 

 Potanin in Mongolia ; the work of N. M. Prshevalsky, 

 "Travels in the Deserts of Central Asia" will con-ist of six 

 volumes, with more than 120 drawings and maps, four volumes 

 being devoted to the zoology, botany, and geology of these 

 countries ; the first volume is already finished by the author, as 

 well as several parts of the following volumes : — An interesting 

 map of Jungaria, drawn up by the Swedish Lieutenant Renat in 

 the eighteenth century, after several months' imprisonment by 

 Kalmuks, was published last year by A. S. Maksheef. Finally, 

 the " Report " mentions also a series of pamphlets, in French, 

 published for the Geographical Exhibition at Venice, which 

 contains very good reviews of scientific work done in Russia in 

 hydrography, zoo-geography, botanical geography, geology, and 

 statistics during the last five years. 



The ninth volume of the Memoirs of the Society for the 

 Physico-Geographical Section contains jan excellent work by 

 A. W. Kaulbars on the delta of the Amu-daria— unhappily 

 without the atlas of maps and drawings, which the Society was 

 unable to publish. The tenth volume will contain the materials 

 collected by the expedition of Karelin in 1830, which are not 

 yet published. 



PRELIMINARY NOTICE OF THE RESULTS 

 ACCOMPLISHED IN THE MANUFACTURE 

 AND THEORY OF GRA TINGS FOR OPTICAL 

 PURPOSES 1 



IT is not many years since physicists considered that a spec- 

 troscope constructed of a large number of prisms was 

 the best and only instrument for viewing the spectrum, where 

 great power was required. These instruments were large aid 

 expensive, so that few physicists could possess them. Prof. 

 Young was the first to discover that some of the gratings of 

 Mr. RutheiTurd showed more than any prism spectro;COpe 

 which had then been constructed. But all the gratings which 

 had been made up to that time were quite small, say I inch 

 square, whereas the power of a grating in resolving the line of 

 the spectrum increases with the size. Mr. Rutherfurd then 

 attempted to make as large gratings as his machine would allow, 



1 By Prof. H. A. Rowland. (Extract from Johns Hopkins University 

 Circular, No. 16.) Communicated by the Author. 



