Feb. 13, 1890] 



NATURE 



351 



Tiot observe it at maximum. A further examination is therefore 

 required. Bright lines should also be carefully looked for, in 

 order to determine whether the appearance of bright lines at the 

 maxima of stars of Group II. is general. The period is given by 

 Gore as 256 days, and the range as from 7 '5-8 "5 at maxi- 

 mum to < I2'2 at minimum. The maximum will occur on 

 February 24. A. Fowler. 



Spectrum of the Zodiacal Light. — In this month's 

 Observatory, Mr. Maxwell Hall gives the results of a series of 

 observations of the zodiacal light made at Jamaica. The obser- 

 vations are divided into three groups, according to the angular 

 distance from the sun of the part of the zodiacal light observed. 

 With respect to the first group, made at a distance of 50° from 

 the sun, it is noted that the spectrum was seen as a faint white 

 continuous band, commencing suddenly at X 561, and extending 

 as far as G, where it died out very gradually. The limit was 

 well determined by comparison with the carbon flutings at 

 W 470, 517, and 564. The result of the second group of ob- 

 servations, made at a distance of 22° from the sun, showed that 

 the spectrum commenced at A. 561, but not so suddenly; its 

 feeble maximum was transferred to about A. 517; from thence 

 it was tolerably uniform to about \ 497, and then it gradually 

 diminished and faded away at G. 



The ob<ervations made at a distance of 15° from the sun gave 

 X 562 for the limit of the red end of the spectrum, and G as 

 before for the violet end. But the spectrum did not commence 

 at all suddenly: the stronger maximum was still at A 517: it 

 was fairly uniform from thence to A 497, and then faded away. 



Observations of twilight are needed to determine whether, as 

 it grows more and more faint, the maximum appears to shift 

 towards the red end of the spectrum or not ; if not, the change 

 in intensity of portions of the spectrum of the zodiacal light as 

 observations are made at varying distances from the sun are 

 peculiar to it, and need further investigation. 



Solar and Stellar Motions. — Prof. J. R. Eastman, in his 

 address as retiring President of the Philosophical Society of 

 Washington, delivered December 7, 1889, gave an exhaustive 

 account of the investigations that have been made to determine 

 the co-ordinates of the solar apex and the annual value of the 

 motion of the solar system. His investigations into the relation 

 between stellar magnitudes, distances, and motions, show that, 

 in opposition to the assumption generally accepted, which asserts 

 that the largest stars are nearest the solar system, there is an 

 almost uniformly increasing proper motion as the stars grow 

 fainter. Forty-six stars, that is, practically all those whose 

 parallaxes have been well determined, have been tabulated and 

 arranged in five nearly equal groups according to the magnitude 

 of their proper motion. The following table gives the mean 

 results found for each of the groups: — 



Number of Stars Mean 

 in Group. Magnitude. 



5-57 

 5-59 

 3 "37 

 2 36 

 2-84 



Mean Proper 

 Motion. 



• 4-93 



• 2-33 

 I 04 



. 0-38 

 006 



Mean 

 Parallax. 



0-32 

 0'20 

 020 



o-i6 



0-13 



The mean magnitude of the first two groups is 5*58, and the 

 mean proper motion is Z-"()T). Of the last three groups the 

 mean magnitude is 2'86, and the mean proper motion is o"49. 



If the 46 stars investigated be arranged according to the 

 magnitude of their parallaxes, it is found that 18 of them have a 

 parallax greater than o" '2, The mean magnitude of these stars 

 is 5 '56, and the mean parallax is o-"34. Of the remaining 28 

 stars the mean magnitude is 2-89, and the mean parallax is 

 o"ii. J'rom this it would appear that, if any law can be 

 formulated from the observed data, it must be that the fainter 

 rather than the brighter stars are nearest the solar system. 



Dun Echt Observatory.— The Earl of Crawford, in a 

 circular issued on the 29th ult. , expresses his thanks for the hearty 

 co-operation he has met with at all hands in his endeavours to 

 advance the science of astronomy. Although some little time 

 will elapse before all the instruments can be removed from Dun 

 Echt to the Royal Observatory at Edinburgh, the former observa- 

 tory must be looked upon as closed, and the generous donor 

 trusts that the astronomical friends who have for years con- 

 tinued to enrich the library at Dun Echt Observatory with 

 donations of books and pamphlets will extend their liberality 



to the new home of the collection at Edinburgh. The important 

 astronomical work done by the Earl of Crawford personally, 

 and at his observatory, has contributed, in no slight degree, to 

 the progress of astronomy, and the very generous gift to the 

 nation of the entire contents of the observatory at Dun Echt is 

 worthy of the man, and appreciated by all friends of the science 

 throughout the world. 



Melbourne Observatory. — We have received from Mr. 

 Ellery the volume containing the results of transit circle obser- 

 vations made from the beginning of 188 1 to the end of August 

 1884. The separate results for R.A. and N.P.D. have been 

 taken directly from the transit books, and also the observer's 

 estimates of the magnitude. The places and magnitudes of the 

 stars given in the annual catalogues have been derived from these 

 separate results by taking their arithmetical mean. 



GEOGRAPHICAL NOTES. 



At the meeting of the Royal Geographical Society on Monday, 

 Mr. Douglas W. Freshfieldreadamostinterestingpaperon "Search 

 and Travel in the Caucasus : an account of the discovery of the 

 fate of the party lost in 1888." He began by acknowledging 

 his obligations to M. de Stael, the Russian Ambassador to the 

 Court of St. James's, the officials at Vladikavkaz, and more 

 particularly to MM. Jukofif and Bogdanoff, of the Russian 

 Survey, for the facilities and assistance given to him and his 

 companions in carrying out the object of his journey. The 

 topographical information accumulated by the surveyors had 

 been placed at his disposal with the greatest readiness, and part 

 of the result might be seen in the great map (6 inches to the 

 mile) of the central group hung on the wall. The heights of 

 the principal peaks were now ascertained. There were eight 

 higher than Mont Blanc, and fifteen of over 15,000 feet. The 

 four highest are Elbruz, Koshtantau, Shkara, and Dychtau. 

 Ushba is 15,600 feet. Mr. Freshfield briefly described the new 

 carriage pass, the Mamison, 9400 feet, from Vladikavkaz to 

 Kutais. Its scenery is finer than that of the Dariel, and the 

 road has been well engineered, but it will shortly fall into ruin 

 unless a service is organized for its maintenance. He referred 

 to the remarkable old Ossete sanctuary of Rekom, at the foot 

 of the Ceja Glacier, and to the tombs found at Chegem, and 

 exhibited a collection of metal and other objects discovered 

 mostly at Styr Degir. In many villages small settlements of 

 "Mountain Jews" were found. There were over 20,000 of 

 this race in the Caucasus, and a work on them has lately been 

 published at Moscow. The author, M. Mirimisoff, states that 

 their beliefs and superstitions are singular, and show Persian 

 influence, but they have had for centuries no connection with 

 the rest of their race, from which they were probably 

 separated at a very early date. The party had crossed five 

 high glacier passes before reaching Suanetia. Here Mr. 

 Freshfield and Captain Powell were the guests of Prince 

 Atar Dadish Kilia, the representative of the family who once 

 ruled Lower Suanetia. He now spends a few months in the 

 summer at his house at Ereri, dispensing hospitality in feudal 

 fashion among his retainers. The population assembles every 

 Sunday for games on the green, and the women sing ballads re- 

 counting incidents in local history or tales of love and revenge. 

 The Leila peaks (13,400 feet) south of Suanetia were ascended 

 for the first time. They are pre-eminent in forests and flowers. 

 One of the glaciers falls over a cliff in avalanches into a glen 

 which is a bed of wild roses and yellow hlies, growing often with 

 fourteen blooms on one stalk. From Suanetia to Sukhum 

 Kaleh the travellers forced a way with mules through an almost 

 trackless forest, and down the deserted valley of the Kodor, the 

 region that was once Abchasia. Strange tales are told of the 

 forest, even by Russian officials, who declared that a wild race, 

 without villages, arms, or clothes, haunted its recesses. No one 

 was met, however, but a few hunters ani shepherds. Bit con- 

 siderable difficulty was met with in forcing a way through the 

 tangle of fallen timber and finding a passage over the torrents, 

 and the native guides employed deserted the travellers before 

 they reached Lata, the first Russian station on the Kodor. Mr. 

 Freshfield proceeded to relate in detail the incidents of the 

 search undertaken by Mr. C. Dent and himself, with the 

 aid of Mr. H. Woolley and Captain Powell, for traces 

 of the fate of the mountaineers, Mr. W. F. Donkin, Mr. 

 H. Fox, and two Meiringen guides, lost in August 1888, 

 It was known, from a note in a diary left by Mr. Fox in a lower 



