DEPARTMENT OF MERIDIAN ASTROMETRY. 197 



placed in radial-velocity determinations, namely, Carbon 4267, H7 4340, Mg 

 4481, and the four helium lines in the region used, are double, with unequal 

 components, and therefore not suited for primary radial velocity work. 



STAFF. 



The Director has been engaged on investigations in statistical fields and 

 has likewise devoted some study to the question of differential refraction as 

 it affects the observations in process of reduction and for future development 

 of the subject. Dr. Sebastian Albrecht continued his researches on standards 

 of wave-length. Mr. Sherwood B. Grant and Mr. Heroy Jenkins have 

 assisted in the general work. The efforts of Mr. Harry Raymond have covered 

 all departments of our activities. Mr. Arthur J. Roy supervised the reduction 

 of zenith-distances until March, since when he has been engaged on special 

 tests of the observations. Mr. William B. Varnum has devoted his time to 

 the study of differential refraction and to preparation of the observations for 

 the inclusion of this correction. Dr. Ralph E. Wilson has made a study of 

 the red stars and in addition has collaborated with Mr. Varnum, Miss Alice 

 M. Fuller has continued as secretary of the Department. 



The energies of the computing staff have mainly been confined to computa- 

 tions arising from the detection of the effect of differential refraction in the 

 observations. It has consisted of Miss Marion F. Benjamin, Mrs. Lillian 

 F. Blanchard, Miss Grace I. Buffum, Mrs. Livia C. Clark, Miss Grace Cramer, 

 Miss Isabella Lange, Miss Marie Lange, Miss Mary M. Kampf, and Miss 

 Frances L. MacNeill. In addition there have been three temporary com- 

 puters. 



