May 4, 1905 J 



NA TURE 



19 



been revised thoroughly, the chapters re-arranged, and 

 much fresh matter introduced. The extra pages supply a 

 description of Wheatstone's ABC instrument, a more de- 

 tailed reference to batteries, single-needle working, duplex 

 and Wheatstone automatic systems, repeaters, test cases, 

 concentrator switch, wireless telegraphy, and other subjects. 



No. 5 of the Central — the magazine of the Central 

 Technical College — is very good, and may be regarded as 

 even constituting an advance on its predecessors. It con- 

 tains an account by Mr. R. Freeman of the design and 

 construction of the steel-work of the bridge over the 

 Zambezi at \'ictoria Falls, a continuation of the series of 

 articles by Prof. Armstrong on the mechanism of com- 

 bustion, and a description of the Klingenberg carriage 

 switchgear by Mr. J. D. Griffin. The magazine is well 

 and copiously illustrated. 



We have received from Mr. Geoffrey Martin a copy of 

 a paper on the theory of solution, published in the Journal 

 0/ Physical Chemistry (vol. ix. p. 149), giving a detailed 

 account of views already briefly stated in a letter to 

 Nature (vol. lx.x. p. 531). .^n attempt is made to explain 

 the fundamental facts that for all substances there is a 

 limit of solubility in each solvent, that the solubility in- 

 creases as a rule with the temperature, and that molecules 

 often dissociate on passing into solution. 



Among the popular science lectures to be delivered at the 

 Royal Victoria Hall, Waterloo Bridge Road, during May 

 are the following : — May 9, fishes old and new, Dr. Smith 

 Woodward, F.R.S. ; May 23, some summits of the lost 

 continent Atlantis, Mr. H. Ling 



OUR ASTRONOMICAL COLUMN. 



Discovery of a Tenth .Satellite to Saturn. — A tele- 

 gram from the Kiel Centralstelle announces the discovery 

 of a tenth satellite to Saturn by Prof. W. H. Pickering, 

 who, it will be remembered, also discovered Phoebe, the 

 ninth satellite. 



The newly discovered satellite is very faint, being re- 

 ported as three magnitudes fainter than Hyperion, the 

 seventh satellite, which has a magnitude of about 17 ; its 

 period is given as 21 days, and its orbital motion is direct. 



The Alleged Identity of Comets " Brooks 1S89 " and 

 Lexell. — An abstract of a paper by Dr. Charles L. Poor, 

 wherein he discusses the identity of Brooks's i88g comet 

 with the object known as Lexell 's comet, is given in No. 4, 

 vol. xiii., of Popular Astronomy. After mentioning the 

 discovery and subsequent history of each body, he discusses 

 the various perturbations to which each has been subjected, 

 and then gives the results obtained from a re-computation 

 of the orbit of Brooks's comet, using the observational data 

 secured during the re-appearance of 1903. Finally, he 

 arrives at the conclusion that the objects are not identical, 

 although further evidence will be necessary before the 

 question can be settled definitely. 



Ancient Drawings of Celestial Phenomena. — Parts 

 xiii. and .\iv. of the current volume of Das Weltall con- 

 tain an interesting article by Dr. W. Lehmann, of Berlin, 

 in which the ancient Mexican accounts of solar eclipses, 

 comets, &c., are discussed. The article is freely illustrated 

 by drawings of eclipses, comets, the moon, planets, &c., 

 taken from the old accounts, and these drawings are most 

 interesting as depicting the old Mexican ideas of these 

 phenomena. For instance, the first is a contemporary 

 drawing of the total solar eclipse of 1531 a.d., and shows 

 plainly immense prominences and coronal wings. 



Mount Wilson Observ.«ory. — In No. 2, vol. xxi., of 

 the Astrophysical Journal, Prof. Hale gives an account of 

 the conditions of solar research at Mount Wilson, Cali- 

 fornia, where he has recently established the Solar Observ- 

 atory of the Carnegie Institution of Washington. In the 



NO. 1853, VOL. 72] 



first of the two articles he enumerates the requirements of 

 the site of such an observatory, and then discusses in detail 

 the meteorological conditions, the seeing, the transparency 

 of the atmosphere, and the instruments available at Mount 

 Wilson. 



In the second article the author describes the foundation, 

 the equipment, and the programme of the observatory, and 

 illustrates his description with photographs and diagrams 

 of the site and of the various instruments and houses 

 already erected or in course of erection. 



Anomalous Dispersion and " Flocculi." — In No. 3, 

 vol. .xxi., of the Astrophysical Journal, Prof. Julius 

 advances the theory of anomalous dispersion to explain the 

 varying appearances of the flocculi on spectroheliograph 

 photographs. The " dark flocculi " of Prof. Hale are ex- 

 plained by the incurvation of the direct rays producing an 

 excess of light in the bright flocculi, and therefore a deficit 

 elsewhere, hence the dark regions naturally ensue. 



The differences between the H, (calcium) and H/3 

 (hydrogen) pictures obtained by Prof. Hale are explained 

 by the supposition that the H/3 rays are less strongly 

 incurvated, and therefore rays of more varied refractive 

 indices pass through the secondary slit, thereby producing 

 a less dark and less defined image. On this assumption 

 Prof. Julius states that the hydrogen photographs would 

 show the fine details seen on the K, photographs if the 

 dispersion employed were greater, or if the secondary slit 

 were used narrower. Without requiring any other hypo- 

 thesis. Prof. Julius explains by this theory all the anomalies 

 seen on the spectroheliograms. 



In the same journal, the same author also discusses the 

 " dispersion bands " seen in the spectra of S Orionis and 

 Nova Persei, and, inter alia, arrives at the conclusion 

 that the former star is not a spectroscopic binary. 



Astronomical Society of America. — Abstracts of sixteen 

 of the numerous papers read at the sixth meeting of the 

 Astronomical and Astrophysical Society of America, held 

 at Philadelphia last December, are given in No. 533 of 

 Science by Mr. Frank B. Littel. The various titles are too 

 numerous to mention here, but amongst them we may 

 notice " The Constant of Aberration," by Prof. C. L. 

 Doolittle, in which the author obtains the value 2o"-S40 + 

 00055 from a series of zenith telescope observations made 

 between December, 1889, and December, 1903 ; " The Re- 

 flex Zenith Tube," by the same author; " Variation of the 

 Bright Hydrogen Lines in Stellar Spectra," by Miss Annie 

 J. Cannon; " Planetary Spectrograms" and "The Canals 

 of Mars," by Mr. Lowell ; " The Coordination of Visual 

 and Photographic Magnitudes," by Mr. J. A. Parkhurst ; 

 and " Recent Researches of the Henry Draper Memorial," 

 by Prof. E. C. Pickering. 



COLOUR IN WASPS OF THE GENUS 

 POLISTES. 



T N the paper referred to below' the author deals very fully 

 with the various colour variations observable in the 

 species of the genus under notice, and a very interesting 

 account is given of the variability in colour-pattern, and of 

 its gradual development in the nymphal and imaginal 

 stages, illustrated by coloured plates i. and ii. A chemical 

 analysis of the nature of the pigments is also given, and 

 illustrations of the layers in which the pigments are located. 

 Coloured plates iii. and iv. give figures of several of the dif- 

 ferent species of the genus — besides these plates there are ex- 

 cellent maps, showing the distribution of the various forms, 

 and elaborate diagrams are provided, indicating the vari- 

 ations observable. The author has evidently spared no pains 

 to render the treatment of the subject as exhaustive as 

 possible, and as a study of colour variation this treatise 

 seems to leave little to be desired. The problem attacked in 

 this work, viz. " an inquiry into the nature and probable 

 causes of specific differentiation in the genus Polistes," is 

 one which is both difficult and perple.xing. 



The author commences at once by saying, " apart from 

 differences in size, the characters used to separate the species 

 are based almost exclusively on colour ; accordingly, this in- 



1 "Coloration in Polistes." _ By Wilhelmine ISI. Enteinan. Pp. 88 

 6 plates. (Carnegie Irtslitution'of vVashington, November, 1904. 



