24 SCIENCE PROGRESS 



Chazy, J., Sur certaines trajectoires du probleme des n corps, Bull. Astr. 



35, 321, 1919. 

 Jeans, J. H., The Configuration of Rotating Compressible Masses, Phil. Trans., 



ser. A., 218, 157, 1919. 

 Palmer, Margaretta, The Definitive Orbit of Comet 1786. II, Astron. 



Journ. 31, No. 744, 19 18. 

 Variable and New Stars. Pickering, E. C, Maxima in 1919 of Variable Stars 



of Long Period, Harv. Circ. 212. 

 Eddington, A. S., On the Pulsations of a Gaseous Star and the Problem of the 



Cepheid Variables, Pt. I., M.N., R.A.S. 79, I, 1918 ; Pt. II., ibid. 79, 177, 



1919. 

 Dawson, B. H., The Period of 004872 V Tucanae, Astroph. Journ. 48, 310, 1918. 

 Martin, C, and Plummer, H. C, The Short Period Variable R R Ceti, M.N., 



R.A.S. 79, 190, 1919. 

 Turner, H. H., Note on the Nebulosity round Nova Persei, M.N., R.A.S. 79, 



23, 1918. 

 Newall, H. F., On the Spectrum of Nova Aquila, 1918, M.N., R.A.S. 79, 31, 



1918. 

 Stellar Distributions and Motions, etc. Charlier, C. V. L., Studies in Stellar 



Statistics, IV. Stellar Clusters and Related Celestial Phenomena, Lund Medd. 



Ser. II., No. 19, 1918. 

 Gyllenberg, W , On the Motion and Distribution of the Long Period Variable 



Stars, Ark. for Mat. Ast. och Fys. 14, No. 5, 1918. 

 Shapley, H., Studies based on the Magnitudes in Stellar Clusters. 8th paper, On 



the Luminosities and Distances of 139 Cepheid Variables, Astroph. Journ. 48, 



279, 191 8. 9th paper, Three Notes on Cepheid Variation, Ibid. 49, 24, 1919. 



10th paper, A Critical Magnitude in the Sequence of Stellar Luminosities, 



Ibid. 49, 96, 19 19. 

 Perrine, C. D., On the Cause of the Distance Velocity Equation in Stellar 



Motions, II, Astroph. Journ. 48, 295, 1918. 

 Hertzsprung, E-, Bemerkungen zur Statistik der Sternparallax, Ast. Nach- 



No. 4975, 1919. 

 Jeans, J. H., The Evolution of Binary Systems, M.N., R.A.S. 79, 100, 1918. 

 Bergstrand, 6., Sur le groupe des e*toiles a helium dans la constellation 



d'Orion, Nova Act. Reg. Soc. Scient. Upsala, Ser. IV., 5, No. 2, 1919. 

 Dyson, F. W., and Thackeray, W. G., Proper Motions of the Stars in Zone 



24"-32* "N. Dec. in Relation to Spectral Types, M.N., R.A.S. 79, 201, 



I9I9- * 



Jeans, J. H., The Present Position of the Nebular Hypothesis, Scientia, 24, 1918, 



Oct. 



SCHOUTEN, W. J. A., The Parallax of Some Stellar Clusters, Observatory, 42, 112, 

 1919. The Distribution of the Absolute Magnitudes among the Stars in and 

 about the Milky Way, Proc. Amst. Acad. Sci. 21, 518, 1918. 



Boss, L., The Vertex of Stellar Motions, Astroph. Journ. 32, No. 747, 1919. 



Miscellaneous. Gyllenberg, W., The Theory of the Equatorial, Ark. for Mat. 

 Ast. och Fys. 13, No. 19, 1918. Die bestimmung der Einstellungsfehler 

 eines Aquatorials durch Differential-messungen, Ibid. 13, No. 9, 1918. Sur 

 la reduction des cliches astrophotographiques et la conversion des mesures 

 en A. R. et D, Lund Medd. II. No. 18, 1918. 



Baillaud, B., Sur les relations entre les co-ordonnees rectilignes normale d'une 

 meme eHoile sur deux cliches differents, M.N., R.A.S. 79, 151, 1918. 



