142 ANNUAL EEPOET SMITHSONIAN INSTITUTION, 1912. 



the present time have been dupUcated. The positions of the planets 

 will be determined only by two independent systems of tables. 

 Greenwich time will be universally used for the ephemerides and 

 unity will be observed for the more important constants (solar paral- 

 lax, precession, nutation, aberration). The campaign actively pushed 

 during recent years for carrying the aberration constant from 20.47" 

 up to 20.53'' can be considered as having failed. The latter figure 

 is irreconcilable with the solar parallax obtained from the general 

 discussion of the Eros observations. 



