55* 



NA TURE 



[February 8, 1906 



owing to its close proximity to the sun, and should be 

 looked for immediately after sunset in the south-west 

 quadrant, near to the horizon. 



Comet 1906a. — Numerous observations of the new comet 

 discovered by Mr. Brooks at Geneva, U.S.A., have been 

 made, and from the positions determined on January 28, 

 29, and 30, the following elements and an ephemeris, of 

 which a part is given below, have been calculated by 

 Messrs. Crawford and Champreux : — 



Elements. 

 T = ioo5 Dec. 1947 G.M.T. 



00 = 86 22 1 

 n = 2S5 27 ' 1906-0 

 / = 1 26 49 1 

 ,/ =1-2826 



Ephemeris 12I1. G.M.T. 

 1906 a 5 Brightness 



Feb. 8 ... 15 50-4 ... +76 37 ... 1-04 



„ 12 ... 15 05-9 ... +78 37 ... 1-05 

 Brightness at time of discovery =10. 

 Thus it will be seen that the comet is now travelling due 



north, and is easily circumpolar, but it is in a better 



position for observations after midnight (Kiel Circular, 

 No. 85). 



A New Method of determining the Moon's Position 

 Photographically. — The chief difficulty in photographically 

 recording the moon's position among the stars, for the 

 purpose of determining the errors in the ephemeris, arises 

 from the fact that if the exposures be long enough to record 

 the faint, surrounding stars, the moon's image is tremen- 

 dously over-exposed, and the star images are lost in the 

 light-fog caused by the prevailing moonshine. Several 

 methods of overcoming this difficulty have been proposed, 

 and Mr. Wade, of the Helwan Observatory, Egypt, now 

 suggests another, which, from his preliminary experiments, 

 promises to be successful. 



In this method the camera is mounted so that its optical 

 axis passes horizontally through the centre of an ordinary 

 coelostat, but the mirror of the latter, instead of being 

 worked to a true plane, is figured as a prism, the two 

 faces of which are inclined at an angle of 7j°, and the 

 edge of the prism is arranged parallel to the polar axis. 

 Thus the photograph obtained includes two fields which 

 are, actually, separated by 15 in right ascension. 



The coelostat is arranged so that one face of the prism 

 reflects the moon's image into the camera, whilst the other 

 face reflects the field of stars situated about 1 hour in 

 right ascension from the moon, and therefore beyond the 

 range of strong moonlight. Then the reflected lunar 

 image is intercepted whilst the reflected star images are 

 exposed for 2J minutes, when an instantaneous ex- 

 posure on the moon is made. The operation is completed 

 by exposing the star-field for a second 2 J minutes. By 

 this method Mr. Wade has obtained a number of successful 

 negatives with a 2-inch visual achromatic Dallmeyer lens 

 and a coelostat of 4 inches diameter (Monthly Notices 

 Royal Astronomical Society, vol. lxvi., No. 2). 



A Catalogue of Spectroscopic Binaries. — A novel and 

 important catalogue, published by the Lick Observatory as 

 Bulletin No. 79, has just been received. It contains all 

 the known particulars of the orbits of the spectroscopic 

 binary stars discovered prior to January 1, 1905. 



On that date 140 of these objects were known, 72 of 

 them having been discovered by the Lick observers and 

 41 at the Yerkes Observatory. 



When one remembers that the first of these interesting 

 objects, ( Ursa; Majoris, was discovered by Prof. Picker- 

 ing so recently as 1889, it becomes evident that this field 

 of research is likely to contain ample scope for further 

 work ; therefore in order to simplify matters for future 

 observers Prof. Campbell and Dr. H. D. Curtis have 

 collected all the known results into the present catalogue. 

 In addition to the positions, magnitudes, spectral types, 

 and orbital details of the binaries, the catalogue contains 

 a valuable column in which the name of the discoverer 



and references to the bibliography of each binary, together 

 witli brief notes, are given. 



Observations of the Lyrid Meteors, April, 1904. — In 

 No. 4067 of the Astronomische Nachrichten Dr. jiff Kavan, 

 of the Prag-Smichow Astronomical Institute, gives the 

 results of his observations of the Lyrids on April 18, 19, 

 20, and 21, 1904. 



Forty-five meteors were observed, twenty of them being 

 recorded between I2h. 5m. and 15I1. 25m. (M.E.T.) on 

 April 19. From an analysis of the records, Dr. Kavan has 

 deduced two radiant points for this shower as follows :— 



(1) ct = 27S : o 



(2) = 247-0 



5= +30-5 (near Lyrse) 

 S= + 31 5 (near £ Herculis 



NO. 1893, VOL. 73] 



REPORT OF THE MEETING OF THE 

 SOLAR COMMISSION AT INNSBRUCK. 

 '"THE commission was constituted by the following action 

 of the Southport meeting of the International Meteor- 

 ological Committee thus reported : — 



" Discussion of the relation of meteorology to astro- 

 physics." 



" The members of the Committee had previously taken 

 part in a discussion of this subject at a meeting of Section A 

 of the British Association ; and Mr. Shaw proposed that a 

 Commission should be appointed to review and discuss 

 meteorological observations from the point of view of their 

 connection with solar physics. Mr. Shaw's motion was 

 adopted, and MM. Lockyer, Shaw, Pernter, and Angot 

 were elected to serve on this Commission with power to 

 add to their number and to elect their officers." 



The following is the list of those who have been 

 appointed members of this commission up to the present 

 time : — 



M. A. Angot, Bureau Central Meteorologique, Paris. 

 Prof. H. J. Angstrom, University, Upsala. 

 Geheimrat oberregierungs von Bezold, Berlin. 

 M. Teisserenc de Bort, Observatoire de Trappes, pres 

 Paris. 



Prof. F. H. Bigelow, Weather Bureau, Washington. 

 Prof. Birkeland, University of Christiania. 

 Rev. G. R. Cirera, S.J., Observatorio del Ebro, Tortosa, 

 Spain. 



Dr. W. G. Davis, Oficina Meteorologica Argentina, 

 Cordoba, Argentine Republic. 



M. H. Deslandres, Observatoire d'Astronomie physique, 

 Meudon, Seine et Oise. 



Sir John Eliot (secretary), 79 Alleyn Park, Dulwich, 

 London ; Bon Porto, Cavalaire, Var, France. 



Mr. G. E. Hale, Solar Observatory, Mount Wilson, 

 California, U.S.A. 



Hofrat Prof. Dr. J. Hann, 19 Hohe Warte, Vienna, 

 Austria. 



M. M. S. Hepites, Institut Meteorologique, Bucarest, 

 Roumania. 



M. Janssen, Observatoire d'Astronomie physique, Meudon, 

 Seine et Oise. 



Prof. W. H. Julius, Rijks Universiteit, Utrecht, Holland. 

 Hofrat. Prof. Dr. N. Thege v. Konkoly, k. meteor. 

 Reichsanstalt, Budapest. 



Prof. Dr. W. Kdppen, Seewarte, Hamburg. 

 Mr. S. P. Langley, Secretary of the Smithsonian Institu- 

 tion, Washington, U.S.A. 



Sir Norman Lockyer (president), Solar Physics Observ- 

 atory, South Kensington, London. 



Dr. W. J. S. Lockyer, Solar Physics Observatory, South 

 Kensington, London. 



Captain J. H. Lyons, R.E., Survey Department, Cairo, 

 Egypt. 



M. E. Marchand, Observatory, Pic du Midi. 

 Prof. H. Mohn, Meteorologische Institut, Christiania. 

 Hofrat. Prof. Dr. J. M. Pernter, Hohe Warte, Vienna, 

 Austria. 



Prof. Ricc6, University of Catania, Sicily, Italy. 

 Prof. G. B. Rizzo, University of Messina, Sicily, Italy. 

 Mr. A. L. Rotch, Blue Hill Meteorological Observatory, 

 Cambridge, Mass., U.S.A. 



Sir Arthur Riicker, 19 Gledhow Gardens, London, S.W. 



