11 E 



8500 Motion in the line of sight. 



Methods. 

 Results. 

 8550 Variable motion in the line of sight. 



8560 Spectroscopic observations of Visual Double Stars. 



8600 Spectroscopic Binary and Multiple Systems. 



8620 Orbits from spectroscopic observations (for Tiieorv 



see 1820). 

 8630 Parallax from spectroscopic observations (for Theory 



see 1820). 



ANCIENT ASTRONOMY AND ASTROLOGY. 

 Ancient Astronomy. 



9000 General. 



9020 Further sub-divisions according to Countrie.-; and 



Epochs. 



Astrology. 



9050 General. 



9060 Further sub-divisions according to Countries and 



Epochs. 



CHRONOLOGY. 



Measure of Time. 



