234 



NA TURE 



[January 9, 1908 



\ 



ture or movements of living creatures conveniently. It 

 should be of real assistance in the study of numerous 

 small forms of animal life under natural conditions. 



Messrs. Charles Griffin and Co., Ltd., have pub- 

 lished the twenty-fourth annual issue of the " Year-book 

 of the Scientific and Learned Societies of Great Britain 

 and Ireland." The work is, as usual, compiled from 

 official sources, and according to the title-page provides 

 a record of the work done in science, literature, and art 

 during the session 1906-7 by numerous societies and 

 Government institutions. It is surprising to find, however, 

 that in connection with the British Association, the only 

 information in the book is confined to the proceedings of 

 the York meeting in 1906, and no mention is made of the 

 Leicester meeting in August last. Under societies con- 

 cerned with geography, the Geographical Association is 

 not included, though its membership is now nearly 650, 

 and it has branches in various parts of this country and 

 in South Africa. But notwithstanding such defects, which 

 can be remedied easily in the next issue, the compilation 

 should continue to be of real assistance as an index to 

 British scientific associations and their work. 



A LIST of publications of the Carnegie Institution of 

 Washington, already issued or in the press, has just been 

 received ; and it reminds us of the very useful work the 

 institution is doing by the publication of monographs on 

 many scientific subjects of wide and deep interest. About 

 ninety of these memoirs have been published, and most of 

 those containing contributions to natural knowledge have 

 been described in the columns of Nature. Among the 

 works now in the press, we notice an atlas of the Milky 

 Way, E. E. Barnard ; dynamic meteorology and hydro- 

 graphy, V. Bjerknes and J. W. Sandstrom ; the rotation 

 period of the sun, as determined by the motion of the 

 calcium flocculi, G. E. Hale ; inheritance in canaries, 

 C. B. Davenport ; supplementary investigations of infra- 

 red spectra, W. W. Coblentz ; and botanical features of 

 North American deserts, D. T. MacDougall. The publica- 

 tions are sold at a nominal price, and a list can be 

 obtained upon application to the Carnegie Institution of 

 Washington, Washington, D.C., U.S.A. 



OUR ASTRONOMICAL COLUMN. 



Return of Encke's Comet (1908a). — A telegram from 

 the Kiel Centralstelle announces that Encke's comet was 

 found by Prof. Wolf on January 2. 



Its position at 6h. 14.5m. on that date (Konigstuhl 

 M.T.) was R.A. =23h. 3m.' ibs., dec. = i° 19' N., and its 

 magnitude was 13.0. 



The following is an abstract from the ephemeris given 

 in No. 4222 of the Astronomische Nachrichten : — 



1908 



Ephemeris oh. (M.T. Berlin.) 

 '(npp) S(app.) log; 



log. i 



Jan. II ... 23 8 8 ... +2 21-9 ... 02829 ■■• 0-3461 



„ 19 ... 23 17-4 ... +3 7-8 ... 0-2617 ... 0-3477 



., 27 ... 23 27-1 ... +4 3-1 ... 0-2385 ... 0-3469 



Feb. 4 ... 23381 ... +5 75 ... 0-2130 ... 0-3435 



At present the comet is apparently passing through the 

 constellation Pisces towards Aries, and sets nearly due 

 west at about 10 p.m. The calculated time of perihelion 

 passage is April 30, not February 22, as stated in our 

 last issue, 



Saturn's Rings. — No. 4222 of the Astronomische 

 Nachrichten (p. 361, December 18, 1907) contains further 

 notes on the recent appearance of Saturn's rings. 



The Rev. T. E. R. Phillips states that on many 

 occasions since the middle of October he has seen the 

 ring clearly, as an extremelv fine line of light on each 



side of the planet, with his I2j-inch Calver equatorial. 

 This line was not always uniformly luminous, but appeared 

 continuous except on November 8, when an interruption on 

 the following side was suspected. He believes the present 

 visibility of the ring to be due to the sunlight passing 

 through the Cassini division and illuminating the edge of 

 the second ring, which is the brightest part of the system. 



Dr. Lau gives the results of' a number of micrometer 

 observations of the minor axis of the rings, for position- 

 angle, from September 3 to 28, 1907, and shows the differ- 

 ences between the observed and the Nautical .Almanac 

 values. The rings were seen on October 2 at o-2h., but 

 were invisible on October 3 at 23.ih. 



•J The Spectra of Two Meteors. — Using a prismatic 

 camera made up of a Voigtlander euryscope, of 50 mm. 

 aperture and 300 mm. focal length, with a 45° crown- 

 glass prism placed before it, M. Blakjo, of the Moscow 

 Observatory, obtained the spectrum of a meteor on May 

 II, 1904; with another camera an ordinary trail photo- 

 graph was obtained at the same time. Encouraged by 

 this chance fortune, M. Blakjo directed his cameras 

 towards the Perseid radiant on .lAugust 12 of the same 

 year, and was fortunate enough to secure a second meteor 

 spectrum. 



In the first case the meteor was of about the first magni- 

 tude, and of a yellow colour, and the spectrum consists 

 of fine lines, of which, by an ingenious method of com- 

 parison with the hydrogen lines shown in the adjacent 

 stellar spectra, _M. Blakjo determined the approximate 

 wave-lengths to the number of thirteen. 



The second meteor was equally bright and of a pure 

 green colour ; during the second half of its flight it was 

 considerably brighter than at first, and this increase of 

 brightness increased the number of lines shown in the 

 spectrum ; the wave-lengths of ten certain and three 

 doubtful lines were determined, and on comparison it 

 was found that the emission spectra of the two meteors 

 are entirely different from each other. 



In the spectrum of the first meteor, the calcium lines 

 H and K are the brightest, and are accompanied by the 

 line at \ 4227 ; magnesium and potassium are also 

 apparently represented. Helium is apparently the out- 

 standing feature of the spectrum of the second meteor, 

 the lines at W 3810-8, 3888-8, 3964-9, 4026-3, and 4121-0 

 being represented. M. Blakjo accounts for the pure green 

 colour of this object by the presence of the thallium line 

 3t ^ 3775-9 '1 'ts spectrum (Astrophysical Journal, vol', 

 xxvi., -No. 5, p. 341, December, 1907). 



The Constancy of Wave-lengths of Spectral Lines. 

 — The importance of the constancy of wave-length of 

 spectral lines in astronomical, as in terrestrial, spectro- 

 scopy leads Prof. Kayser to discuss the question in No. 3, 

 vol. xxvi., of the Astrophysical Journal. He points out 

 that Exner and Haschek based some of their recent 

 evidence for variation on differences obtained by students 

 in his l.tboratory, and states that, in his opinion, these 

 differences were probably due to errors of the standards 

 employed rather than to any real variability of wave- 

 length. Prof. Kayser also adduces evidence, based on the 

 recent work of Dr. Pfund and of Prof. F.ibry, in support 

 of his view that " the question of the constancy of the 

 wave-lengths is finally settled." 



NEW CHEMICAL LABOR.ATORIES .AT 

 ABERYSTWYTH. 

 'X'HE Edward Davies chemical laboratories at the Uni- 

 versity College of Wales, Aberystwyth, which were 

 formally opened on November 1 by Mr. .Asquith (see this 

 vol., p. 22), have been erected at a cost of 23,000!. by Mr. 

 David Davies, M.P., his mother and sisters, to the memory 

 of the late Mr. Edward Davies, J. P.. and have been handed 

 over to the governing body of the University College of 

 Wales. The laboratories are under the direction of Prof. 

 J. J. Sudborough, and have been in use since the opening 

 of the present session on October 2. 



The laboratories form a separate block of buildings about 

 half a mile distant from the college, and are erected in 

 local stone with Grinshill dressings. On the first floor 

 are two large laboratories (50 feet by 40 feet), each con- 



NO. 1993, VOL. yy] 



