January 23, 1908J 



NA TURE 



!8l 



OVR ASTRONOMICAL COLUMN. 

 Observation of Excke's Comet on December 25, 1907. 

 — From No. 4226 of the Astronomische Nachrichtcn (p. 31, 

 January 7) we learn that, having found Encke's comet on 

 January 2, Prof. Wolf examined some earlier plates, and 

 found an image of the comet on one taken at 7h. 20m. 

 December 25, 1907 (Kbnigstuhl M.T.). Its position at 

 that time was R..\.=22h. 57-4ni., S=+o° 54', and its 

 magnitude 13-0. Owing to its being near the edge of 

 the plate, this image was overlooked at first. From this 

 observation it appears that the recently published ephemeris 

 {Astronomische Nachrichtcn, No. 4222) requires corrections 

 of +24m. and —24'. 



A NEWLY DISCOVERED BRIGHT MiNOR PlaNET (1908 B.M.). 



— A comparatively bright planet was discovered by Dr. 

 Kopfl at Heidelberg on January 4. Its position at 

 i2h. 27.6m. (Konigstuhl M.T.) was a = 7h. 33m. 48s., 

 5 = + 14° 57', and its daily motion —1.4m. and —20'. The 

 magnitude of this object was recorded as 9.2. Dr. 

 Przybyllok observed the planet with the 12-inch refractor 

 of the Astronomischen Institut on January 5, and found 

 it to be equal in magnitude to B.D. + I4°.i7i7 (magni- 

 tude, 9-4) (Astrono)}iiSihc Snchrichteti, No. 4226, p. 31, 

 January 7). 



Measures of Dolule Stars. — In No. 4227 of the 

 Astronomische Nachrichtcn (p. 33, January 8), Messrs. 

 C. P. Olivier and R. E. Wilson publish the results of 420 

 observations of 116 double stars made at the Leander 

 McCormick Observatory, University of Virginia, during 

 Ihe years 1904-7. Seven of the doubles in this list were 

 discovered by Mr. Olivier, and are now published for the 

 first time. Notes as to the probable motions of some of 

 these doubles are appended to the paper. 



Ephemeris for Comet 19071;. — A bi-daily ephemeris for 

 comet 1907<?, covering the period January 13 to 

 February 22, is published in No. 4226 of the Astronomische 

 Nachrichtcn by Herr M. Ebell. An observation by Dr. 

 Wirtz, made at Strassburg on December 4, gave the 

 magnitude as 12.7. 



The Absorption of D, (Helium) in the Neighbour- 

 hood of Sun-spots. — In an article appearing in the 

 Observatory (p. 51, No. 392, January), Father Cortie dis- 

 cusses some photographs of sun-spot spectra obtained by 

 Mr. Nagaraja at the Kodaikanal Observatory last year. 

 The special point of these photographs was that, with a 

 spot near the limb of the sun, they are supposed to show 

 the bright line at the limb and the dark absorption line 

 in the region of the spot at the same time. Father Cortie 's 

 discussion tends to show that the dark line in question is, 

 possibly, not coincident with D,, and is perhaps the water- 

 vapour absorption line at \ 5875-963. He has many times 

 recorded lines attributed to water-vapour in the spectra of 

 sun-spots, and suggests the possibility of the presence of 

 superheated steam in sun-spots. 



In regard to the recent suggestions that a permanent 

 dark D, line occurs in the solar spectrum. Father Cortie 

 points out that Mr. Higgs and he thoroughly investigated 

 the question seventeen years ago, and concluded that there 

 was no permanent dark line coincident with the bright 

 D, ; since then no conclusive evidence has been adduced 

 to lead him to alter that conclusion. 



The Orbit of the Spectroscopic Binary f) .Aquil^. — 

 No. 6, vol. i., of the Journal of the Royal .Astronomical 

 Society of Canada (p. 357, November-December, 1907) 

 contains a preliminary set of elements for the orbit of the 

 spectroscopic binary e Aquilse. This star has a photo- 

 graphic magnitude of 3.6, and its spectrum is of the type 

 \TI<i. Mr. W. E. Harper, of the Dominion Observatory, 

 Ottawa, who publishes the elements, finds that Deslandres's 

 conjecture of a i6.8-day period and a high eccentricitv is 

 confirmed. The present elements give 17-17 davs as the 

 period. —26.7 km. per sec. as the velocitv, 0.725 as the 

 eccentricity, and 8,4i;5,5oo km. as the length of the semi- 

 major axis of the orbit. 



Eclipse Observations, .August, 1905. — No. 15 of the 

 litillctin de I' Academic Jmperiale des Sciences de St. 

 Peter sbourg contains M. Donitch's report of the results 

 obtained by the expeditions dispatched by the academy to 



observe the eclipse of 1905. Two expeditions were 

 organised, one going to .Alcala de Chisvert ^^.Spain), the 

 other to Assouan. The object of the former was to study 

 the chromosphere and corona, whilst the attention of the 

 latter was chiefly devoted to observations of terrestrial 

 magnetism. In the present paper M. Donitch, who 

 directed the expedition to Spain, discusses the purely astro- 

 nomical results. Photographs of the chromospheric spec- 

 trum were obtained, and the wave-lengths and origins of 

 some no lines are given in tabular form. In addition to 

 those of H, He, Ca, Sc, Ti, Cr, Fe, Sr, Vt, and Ba, 

 there are indications of the presence of lines of Co, Zr, 

 Eu, and, possibly, Ge in the spectrum. The depths of 

 the layers of these various elements in the chromosphere 

 were measured, those of hydrogen and calcium giving the 

 highest numbers, 49,300 kilometres and 44,000 kilometres 

 respectively. The dimensions of five prominences as shown 

 in radiations of various wave-lengths are also given. 



The photographs of the corona show it to have been of 

 the " maximum " type, as one would expect in 1905. 

 Reproductions from several of the photographs obtained 

 accompany the paper. 



We have also received a finely illustrated volume con- 

 taining a full discussion of the results obtained by the 

 astronomical section of the Observatory of Cartuja, 

 Granada, Spain. In this work, published under the direc- 

 tion of P. Jos^ Mier y Terdn, S.J., most of the questions 

 and theories arising from eclipse observations are discussed 

 at length, so that the volume, which is printed in Spanish, 

 forms a useful reference work for future observers. 



SCIENCE 



AT RECENT EDUCATIONAL 

 CONFERENCES. 



NO. 1995, VOL. 77] 



T"' 1 1 ERE is no ebb in the tide of educational congresses. 

 On the contrary, the number of teachers' organisa- 

 tions increases year by year, the number holding annual 

 meetings during the last month in London alone running 

 well into double figures. Nor is there any falling off in 

 the vigour of the individual associations ; indeed, in the 

 case of the London County Council Conference, large 

 numbers were unable to gain admission owing to the 

 crowded state of the hall. This particular conference 

 brought together more than twelve hundred workers in 

 education, the majority of whom were teachers in L.C.C. 

 elementary and secondary schools and technical institutes. 

 We propose to review this meeting and that of the Public 

 Schools Science Masters' Association, but desire to preface 

 a few remarks on the effect of the multiplication of 

 societies for the furtherance of various branches of 

 education. 



The time has gone bv when a schoolmaster was ex- 

 pected to be able to teach all the subjects of the curri- 

 culum. Improved methods of teaching have in every sub- 

 ject called for a greater mastery on the part of the teacher, 

 so that just at present we appear to be saved from having 

 a specialist for every subject in the curriculum solely by 

 considerations of financial economy. The science master 

 teaches nothing but science, and is apt to lose interest 

 in, and to be out of touch with, other subjects, and, 

 mutatis mutandis, this is true of the modern language 

 master and of the others. Hence we find segregation of 

 teachers into their respective associations, each dealing 

 with its particular branch of study. The advantages of 

 these independent meetings are not far to seek. If the 

 discussion refers to the teaching of physics, for example, 

 the whole audience may be assumed to h.ave some expert 

 knowledge and to be intimately concerned in arriving at 

 a right judgment. The informal and social side of the 

 meetings, not their least valuable function, may be easier 

 to promote, because each feels that he can exchange views 

 with his neighbour to their mutual profit. But there are 

 drawbacks to this segregation. Nothing was more 

 frequently insisted on during the debates of the Public 

 Schools' .Science Masters than the need for cooperation 

 between the teachers of mathematics and physics. One 

 soeaker urged that nominees of the Public Schools' Science 

 Masters' .Association should confer with nominees of the 

 Mathematical .Association to promote this end. In our 

 opinion, this proposal falls verv short of what is required. 

 It would be better to hold a joint general meeting of the 



