446 



NA TURE 



[March 12, 1908 



be used in all cases in which there is much variation of 

 the radiation with time. On the other hand, if the source 

 of radiation is constant, the radiometer is the most 

 sensitive, particularly in the infra-red. The radiomicro- 

 nieter, although capable of improvement, is not likely to 

 reach one-fifth the sensitiveness of the bolometer. The 

 Rubens thermopile, when its heat capacity is diminished 

 by the use of thinner wire, is as sensitive as the bolometer, 

 Lind is to be recommended for the measurement of very 

 wenlv radiation on account of its greater steadiness. 



According to the tisumi of communications made to 

 the Society fran^aise de Physique on February 7, Drs. 

 Hemsalech and de Watteville find the flame spectra of 

 metals extend far into the ultra-violet, and are much richer 

 In lines than they have been thought to be. The method 

 used by the authors is a modification of that originally 

 used by M. Gouy. They obtain the finely divided material 

 to be studied, and mix it with the gases proceeding to the 

 burner, by forming an electric arc between two electrodes 

 of the material placed in a bulb through which one of the 

 gases passes. If two such arcs between different metals 

 are used, the spectra of the two metals are superposed. If 

 the gas is filtered between the arc and the flame the lines 

 are scarcely affected, while the continuous spectrum is very 

 much diminished in intensity. 



We have received from Messrs. John Wheldon and Co. 

 ■\ catalogue of books and papers offered for sale on micro- 

 scopical science in all its branches, including an important 

 collection of works on Diatomacea;. 



A CIRCULAR has reached us referring to the issue of 

 publications in connection with the Indian Forest Depart- 

 ment. It has been decided that in future the forest litera- 

 ture shall appear in two chief forms, described, respectively, 

 as Indian Forest Records and as Memoirs. In addition 

 lo these publications, it is proposed to issue pamphlets 

 and leaflets on professional subjects. 



The Royal .Statistical Society has issued a new cata- 

 logue, which comprises, with certain exceptions, all works 

 included in the society's library on December 31, 1906. 

 The number of books and separate publications is 

 approximately fifty thousand. The general rules adopted 

 in the compilation of the catalogue are stated with clear- 

 ness, and statisticians should find the new list a great 

 convenience. 



The Society for Promoting Christian Knowledge pro- 

 poses to issue the following books on scientific subjects in 

 May next: — "Turbines," by Engineer-Commander A. E. 

 Tompkins, R.N., second edition, enlarged and revised; 

 "Spinning Tops," by Prof. J. Perry, F.R.S., revised 

 edition, with an appendix on the gyrostat and the mono- 

 rail ; "The Fundamental Conceptions of Chemistry," by 

 Prof. S. M. Jorgensen, translated from the latest German 

 edition, with additions by Mr. M. P. Applebey. 



OVR ASTRONOMICAL COLUMN. 



The P.ieallax of the Andromeda Nebula. — No. 4, 

 vol. viii., of the Astronotniska lakttagelser och Under- 

 -''ftkningar a Stockkolms Ohscrvatorium is devoted to the 

 rtsults of an investigation of the parallax of the Andromeda 

 nebula. The observations on w'hich the results are based 

 were made in two groups, the first set of fifteen photo- 

 graphs being taken during the period 1902-4, the second, 



NO. 2002, VOL. 77] 



including forty-seven photographs, covering the season 

 1904-5. Dr. Karl Bohlin, by whom the investigation has 

 been carried out, describes fully the methods employed, and 

 finds for the parallax of the nebula the definitive value 



+ o"-i7i. 



The Orbit cif 7 N'irgims. — A re-investigation of the 

 orbit of 7 \'irginis has convinced Dr. Dobcrck that the 

 differences between the calculated and observed positions 

 of that star, when near the periastron passage, are at 

 least partly due to the perturbations to which he recently 

 directed attention. It also seems probable that changes 

 in the shapes of the components, and even explosive action, 

 may exert some influence on the orbit. Dr. Doberck 

 suggests that spectroscopic observations of double stars 

 should prove especially useful in cases where the orbit is 

 very eccentric if made while the companion is close to the 

 principal star. The elements now given show the period 

 of y Virginis to be 182-30 years, and the eccentricity of 

 the orbit to be 0-88736. The hypothetical parallax is 

 o"-ii6 {Astronomischc Nachriclitcti, No. 4235, p. 161, 

 February 29). 



The Large Solar Prominence of May 21, 1907. — In 

 No. I, vol. xxvii., of the Astrophysical Journal (p. 78, 

 January), Father F^nyi compares his visual observations of 

 a large eruptive prominence which he observed at Kalocsa 

 on May 21, 1907, with the photographic observations of 

 the same prominence made bv Mr. Fox at the Yerkes 

 Observatory (N.atl're, p. 90, No. 1987, November 28, 1907). 

 The visual observations give lower altitudes than the 

 photographic, and, on comparing the sketch made at the 

 same time as Mr. Fox's second photograph, it is seen 

 that the forms are so different that no part of them can 

 be identified ; on the whole, the sketch more strongly 

 resembles the first photograph made some fifty minutes 

 earlier. The visual observations also show a much quicker 

 ascension of the prominence material than do the simul- 

 taneous photographs, the rate being 54 km. per second 

 instead of 30 km. ; no change of form was observed 

 visually during the time occupied in observing eleven 

 transits. Father F^nyi records that he has never observed 

 the subsidence of a prominence of great height. With 

 prominences of low altitudes the descent of the material 

 is the usual Occurrence, but dissipation at great altitudes 

 appears to be the rule for those which attain great heights. 



Spanish Oeserv.\tions of the Total Solar Eclipse of 

 August, 1905. — The results of the eclipse observations 

 made at Soria, Spain, in August, 1905, by the members of 

 the eclipse expedition from the Marine Observatory of San 

 Fernando, are embodied in a handsome volume recently 

 published under the direction of Captain Don Tomas de 

 AzcArate, director of the observatory. Numerous photo- 

 graphs of the chromospheric spectrum and of the corona were 

 obtained, and some of them are reproduced in the volume. 

 Nearly five hundred lines were measured in the spectra of 

 the chromosphere, and their wave-lengths are given, 

 together with the probable origins and their wave-lengths 

 as determined by Lockyer, Dyson, Evershed, and other 

 eclipse observers. The volume also contains the results of 

 the meteorological observations made at Soria, and the 

 results of the observations of the contacts, &c., made at 

 San Fernando and many other stations in Spain. 



A New Variable of the U Geminorum Type. — A 

 telegram from the Kiel Centralstelle announces that the 

 variable star 31.1907 AurigfE was observed by Prof. 

 Hartwig on March 6 and found to be of the irregular 

 class, similar to U Geminorum ; the magnitude was g-o. 



The Canadian .\stronomical Handbook for 1908. — The 

 second annual handbook published by the Royal Astro- 

 nomical .Society of Canada contains a great deal of in- 

 formation useful to amateur astronomers. Ephemeride-^ 

 and charts for the positions of the major planets, lists of 

 interesting coloured, variable, and double stars, and a 

 calendar of astronomical occurrences for the current year 

 are among the many useful data given, whilst there is 

 also a mass of information more especially useful to 

 Canadian observers. 



