RECENT ADVANCES IN SCIENCE 377 



results are of the high order of accuracy now generally obtained 

 with the photographic method. The programme includes all 

 visual binaries with w T ell-determined orbits, some spectro- 

 scopic binaries, some objects whose hypothetical parallaxes 

 are large, some stars with well-determined parallaxes (for 

 comparison with other determinations), a few stars with large 

 proper-motions or whose determined parallax values are dis- 

 cordant and a few objects of special interest. 



Dyson, Sir F. W., and Thackeray, W. G., The Systematic 

 Motions of the Stars between Dec. -{- 24 and Dec. +32 , 

 M.N., R.A.S. 77, 581, 1 91 7. This is a study of about 12,000 

 proper-motions of stars in the Greenwich 1910 catalogue. 



Pease, F. G., and Shapley, H., The Distribution of Stars 

 in 12 Globular Clusters, Astroph. Journ. 45, 325, 191 7. Counts 

 of stars on photographs of the clusters have been made to test 

 the presence of galactic planes. Distinct evidence was obtained 

 in the majority of cases. 



Sanford, R. F., Some Relations of the Spiral Nebulae to 

 the Milky Way, L.O.B. No. 297, 191 7. 



Bailey, S. I., The Northern Milky Way, H.A. 80, No. 4, 

 1917. A series of nine plates covering the northern half of the 

 Milky Way, uniform with a similar series for the southern half, 

 published in H.A.12, No. 3. The scale is i° = 6mm. The two 

 series together give a continuous photographic representation 

 of the Milky Way on a uniform scale. Notes on points of 

 interest are added. 



Pease, F. G., Photographs of Nebulae with the 60-inch 

 Reflector. Astroph. Journ. 46, 24, 191 7; Mt. Wilson Conts., 

 No. 132. A valuable series of nebulae photographs with long 

 exposures, with descriptive notes. Some of the nebular forms 

 shown are very remarkable. 



Sampson, R. A., Note on the Southern Magnitude Distri- 

 bution with special reference to the Perth Astrographic Zone, 

 MM., R.A.S. 77, 603, 191 7. Evidence as to the galactic con- 

 densation in support of the value deduced by Seares is adduced 

 from the Perth astrographic results. 



PHYSICS. By James Rice, M.A., University, Liverpool. 



The main stream of research in physics is at present directed 

 towards the elucidation of the problem of radiation and the 

 25 



