DECIMAL CLASSIFI CATION 
522.6 
o1 
62 
.63 
64 
635 
66 
67 
68 
69 
bd 
71 
72 
73 
74 
75 
“6 
77 
78 
79 
0 
91 
92 
93 
-94 
95 
96 
97 
08 
99 
223 
Tr” 
4 
18 
16 
17 
Auxiliary observations 
Photometry See 535.2 Optics 
Photografy See 535.85 Optics; 770 Photografy 
Polarization See 535.5 Optics 
Spectroscopy ~~ See also 535.84 
Technic; application to astronomy and use with telescope. For results see 
£23.37, 523.57, 523.67, 523.77, 523.87 
Spheric astronomy See also 514.6 
Celestial sphere Spheric coordinates 
Rectangular coordinates 
Transformation of coordinates 
Differential variations of coordinates 
[nterpolation 
Meridian line Variation of compass 
Reduction of observations to the meridian 
Use of globes 
Corrections 
Parallax 
Refraction See 535.3 Optics 
Semidiameter of celestial bodies 
Aberration 
Precession ~~ See 521.9 
Nutation won 
Personal equation See 522.54 
[nstrumental errors 
Descriptiv astronomy 
Universe 
Structure of universe 
Nebular hypothesis 
Plurality of worlds 
Space and its temperature 
Resisting medium 
Cosmic dust 
Repulsiv force