548 



SCIENCE 



[N. S. Vol. XLIX. No. 1275 



E. V. McCoLLUM, professor of bio-ehemistry, 

 Johns Hopkins University. (Introduced by Dr. 

 Henry H. Donaldson.) 



Friday, April S5, S o'clock 

 George Ellery Hale, Ph.D., Se.D., LL.D., vice- 

 president, in the chair 

 The eclipse expedition from the LicJc Oiservatory : 

 some solar eclipse problems (illustrated) : "W. W. 

 Campbell, director of the Lick Observatory, 

 Mount Hamilton, Calif. 

 Tlie expedition of the Mount Wilson Observato-ry 

 to the solar eclipse of June 8, 1918 (illustrated) : 

 J. A. Anderson, Mount Wilson Solar Observa- 

 tory, Pasadena, Calif. (Introduced by Professor 

 John A. MiUer.) 



A description of the equipment used at Green 

 Kiver was given; the compact arrangement of the 

 different units being the chief feature. Owing to 

 clouds, the results were not what was hoped for. 

 Good photographs of the corona were secured; the 

 wave-length of the green coronal line was quite 

 accurately determined; and certain, data of value 

 for future eclipse work were obtained. 

 The Lowell Observatory eclipse observations, 

 June 8, 1918: prominences and coronal arches 

 (illustrated) : Gael O. Lampland, Lowell Ob- 

 servatory, Flagstaff, Arizona. (Introduced by 

 Professor Eric DooUttle.) 



The author deals with some of the more im- 

 portant results obtained by the expedition sent 

 sent out by his institution, but especial attention 

 is given to the prominences and the detail of the 

 inner corona. Several conspicuous prominences 

 were shown in the photographs and these are gen- 

 erally surrounded by complex coronal structure. 

 These coronal arches or ' ' hoods ' ' are probably 

 among the most conspicuous and remarkable 

 photographed up to the present time. In the pres- 

 ent observations there appears to be no doubt as 

 to the intimate relation between the prominences 

 and the surrounding coronal structure. From a 

 comparison of the observations of earlier eclipses 

 made at different epochs of solar activity it seems 

 probable that complex coronal detail and distiirbed 

 regions of the corona around and in the neighbor- 

 hood of the prominences are more pronounced near 

 sun-spot maxima; that such detail is much less 

 conspicuous and occurs more rarely at or near the 

 minima of sun-spot activity. 



The flash spectrum (illustrated) : Samuel Alfred 

 Mitchell, director, MeOormick Observatory, 

 University of Virginia. (Introduced by Pro- 

 fessor John A. Miller.) 



'Electric photometry of the 1918 eclipse (illus- 

 trated) : Jacob Kunz and Joel Stebbins, Uni- 

 versity of Illinois, Urbana, 111. (Introduced by 

 Professor John A. MiUer.) 



Tlie Sproul Observatory eclipse expedition: The 

 fmm of the coroiml streamers (illustrated) : 

 John A. Miller, director of the Sproul Observ- 

 atory, Swarthmore College, Pa. 



Besults of observations of the eclipse by the ex- 

 pedition from the Yerlces Observatory : Edwin 

 B. Frost, professor of astrophysics and di- 

 rector of Yerkes Observatory, University of 

 Chicago. 



Self-lxmiinoiis night liaze (illustrated) : E. E. Bar- 

 nard, professor of practical astronomy, Univer- 

 sity of Chicago. 



The author dealt with a little-known feature of 

 the night skies. It is a faintly luminous haze that 

 is sometimes visible on otherwise clear nights 

 when the moon is absent. It does not seem to be 

 connected with any known auroral phenomenon. 

 It seems not to be some form of cirrus or cirro- 

 stratus cloud that for some reason, on rare occa- 

 sions, is more or less faintly self luminous at 

 night. The source of its light is unknown. When 

 best seen it is quite noticeable as a streaky 

 luminous haze; sometimes it appears in broad 

 sheets. It drifts easterly over the stars and re- 

 mains visible with a faint steady light for a con- 

 siderable length of time. Sometimes it seems to 

 be absent for several years. At other times there 

 is a great deal of it. It is seen in all parts of the 

 sky, differing thus from the ordinary auroral phe- 

 nomena, which are mostly confined to the northern 

 part of the sky. 



Photometric measurements of stars: Joel Steb- 

 bins, professor of astronomy. University of Illi- 

 nois. (Introduced by Professor Henry Norris 

 Russell.) 



Star clusters and their contribution to knowledge 

 of the universe: Harlow Shapley, Mt. Wilson 

 Solar Observatory, Pasadena, Calif. (Intro- 

 duced by Professor George E. Hale.) 



Tatar material in old Russian: J. Dtnelet 

 Prince, professor of Slavonic languages, Colum- 

 bia University. 



Friday Evening, April S5 



Reception from eight to eleven o'clock in the 

 hall of the Historical Society of Pennsylvania, 



