l66 REPORTS ON INVESTIGATIONS AND PROJECTS. 



STAFF. 



The staff of the Observatory has remained almost unchanged throughout 

 the year. In the absence of Mr, Hale, Mr. Adams has served as acting 

 Director, and has been engaged in stellar spectroscopic work with the 60- 

 inch reflector. Mr. F. H. Scares has continued his photometric investiga- 

 tions on faint stars with the reflector, remaining in charge of the computing 

 division and of the editorial work connected with the Observatory publica- 

 tions. Dr. Arthur S. King has continued to act as superintendent of the 

 physical laboratory in Pasadena. Mr. G. W. Ritchey has resigned from the 

 regular staff of the Observatory, but his services for a portion of his time 

 have been retained for optical work upon the 100-inch mirror. Dr. C. E. St. 

 John has carried on numerous solar spectroscopic investigations with the 60- 

 foot tower telescope. Mr. Ferdinand Ellerman has continued in charge of 

 the observations with the spectroheliographs of the Snow and tower tele- 

 scopes. Mr. H. D. Babcock has devoted a part of his time to stellar spectro- 

 scopic work with the 60-inch reflector and the remainder to investigations in 

 the laboratory in Pasadena. Dr. E. A. Fath has continued his spectroscopic 

 studies upon the spectra of nebul?e and star-clusters and has made many 

 photographs of the Kapteyn Selected Areas with and without color filters and 

 absorption screens. Mr. F. G. Pease assisted during the winter in the stellar 

 spectroscopic work with the 60-inch reflector and has commenced recently a 

 series of direct photographs of nebulae and star-clusters with the same 

 instrument. 



Prof. J. C. Kapteyn, of the University of Groningen, Research Associate 

 of the Carnegie Institution of Washington, has, as usual, spent the months 

 of July and August at Mount Wilson. A large part of his time has been 

 devoted to a study of the problem of streams among stars having spectra of 

 the Orion type, employing for this purpose the radial velocities obtained 

 during the year with the 6o-incli reflector. The close connection of these two 

 lines of work should prove of the greatest value to each. Dr. Henry G. Gale, 

 of the University of Chicago, Research Associate of the Carnegie Institution 

 of Washington, spent the months of March, April, and May in Pasadena 

 engaged in an investigation of the displacements under pressure of the spec- 

 trum lines of iron and titanium in the electric arc and spark. Dr. Arnold 

 Kohlschutter, of the observatory at Hamburg, arrived at Mount Wilson in 

 July and will spend the coming year at the Observatory as a volunteer assist- 

 ant. He is at present engaged in the classification of the stellar spectra made 

 with the 60-inch reflector. 



