Mat 19, 1916] 



SCIENCE 



715 



through the central nucleus nearly at right 

 angles to the plane passing through the ob- 

 server and the major axis of the image. The 

 mass of the nebulas is apparently several times 

 larger than that of the sun. It is suggested 

 that the ring nebulae are not true rings, but 

 ellipsoidal shells. 



6. A Short Period Cepheid with Variable 

 Spectrum: Harlow Shapley, Mount Wil- 

 son Solar Observatory, Carnegie Institu- 

 tion of "Washington. 



The star RR Lyixe is a periodic variable in 

 at least three ways : first, in the light intensity ; 

 second, in the radial velocity; and third, in 

 the spectrum which changes from F to A. 

 A similar spectral change is found in RS 

 Bootis. 



7. The Spectrum of 8 Oephei: Walter S. 

 Adams and Harlow Shapley, Mount Wilson 

 Solar Observatory, Carnegie Institution of 

 Washington. 



At maximum the high temperature lines 

 are very strong and the low temperature lines 

 very weak; while at the minimum the reverse 

 is the case. This indicates that at maximima 

 the temperature of the gases of the star's ab- 

 sorbing envelope is higher than at minimum. 



8. Investigations in Stellar Spectroscopy. I. 

 A Quantitative Method of Classifying 

 Stellar Spectra: Walter S. Adams, Mount 

 Wilson Solar Observatory, Carnegie Insti- 

 tution of Washington. 



Method replaces to a considerable extent 

 direct estimations of spectral type by numer- 

 ical estimates of relative line intensity which 

 may be made with much higher accuracy. 



9. Investigations in Stellar Spectroscopy. II. 

 A Spectroscopic Method of Determining 

 Stellar Parallaxes. III. Application of a 

 Spectroscopic Method of Determining Stel- 

 lar Distances to' Stars of Measured Parallax: 

 Walter S. Adams, Mount Wilson Solar Ob- 

 servatory, Carnegie Institution of Wash- 

 ington. 



The method of computing absolute magni- 

 tudes and parallaxes from the variation of the 

 intensities of lines in the stellar spectriun is 



capable of yielding results of a very consider- 

 able degree of accuracy. 



10. Investigations in Stellar Spectroscopy. 

 IV. Spectroscopic Evidence for the Exist- 

 ence of Two Glasses of M Type Stars: 

 Walter S. Adams, Mount Wilson Solar Ob- 

 servatory, Carnegie Institution of Wash- 

 ington. 



Two groups of M stars are indicated clearly 

 by examination of the intensities of the hy- 

 drogen lines. 



11. The Failure and Revival of the Process of 

 Pigmentation in the Human Skin: A. E. 

 Jenks, Department of Sociology and An- 

 thropology, University of Minnesota. 



It is found that on the one hand, there is 

 an extension of the albinistic areas and on 

 the other a revival of the process of pigment 

 metabolism within an at-one-time albinistic 

 area. 



12. Banded Glacial Slates of Permo-Garhonif- 

 erous Age, showiyig possiMe Seasonal Vari- 

 ations in Deposition: Egbert W. Satles, 

 University Museum, Harvard University. 

 A study of the slate and tillite formations 



of Squantum (near Boston) affords evidence 

 of seasonal changes in the locality, indicating 

 that it was in a temperate zone during Per- 

 mian times as now. 



13. An Extension of Feuerhach's Theorem: 

 F. MoRLEY, Johns Hopkins University. 

 All circular line-cubics on the joins of four 



orthocentric points touch the Feuerbach circle. 



14. Deformations of Transformations of Ri- 

 haucour: L. P. Eisenhart, Department of 

 Mathematics, Princeton University. 



15. Geographic History of the San Juan 

 Mountains since the Glose of the Mesozoic 

 Era: Wallace W. Atwood and Kjrtlet E. 

 Mather, Geological Museum, Harvard Uni- 

 versity. 



The study of the geography of this region is 

 closely related to the geologic studies of the 

 range, but may lead also to a study of anthro- 

 pogeography. 



16. The Age of the Middle Atlantic Coast 

 Upper Cretaceous Deposits: W. B. Clark, 



