PURE SCIENCE 
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522 
’ JI 
II 
12 
13 
14 
15 
10 
2 
21 
22 
23 
24 
25 
26 
27 
28 
20 
3 
31 
32 
33 
34 
35 
36 
37 
38 
4 
41 
42 
43 
44 
45 
46 
47 
5 
nT 
v3 
53 
54 
55 
56 
57 
g8 
Practical and spheric 
Observatories 
General plan, location 
Material and mechanism of dome, drum, etc. 
Transit bildings, wings, etc. 
High altitude observatories 
Portable 
History, reports and serial publications of observatories 
Telescopes "See also 535.83 Optics 
Reflecting 
Refracting 
Eye piece and accessories 
Object glas 
Mounting, tube, etc. 
Equatorial mounting 
Transit mounting 
Observing chairs, etc. 
Famous telescopes 
Meridional instruments 
Finding meridian line 
Mural circles 
Meridian circles 
Transit: placing in position 
Collimation constant 
Level constant 
Azimuth constant 
Other constants, flexure, index error, etc. 
Extra meridional instruments 
Sextant and quadrant, reflecting circle, astrolabe 
Altazimuth 
Zenith telescope 
Transit out of meridian 
Heliometer 
Equatorial 
Prime vertical 
\uxiliary instruments 
Sidereal clock and chronometer 
Electrochronograf 
Micrometers 
Personal equation machine See sa2.07 
For illumination 
For solar ebservation 
Artificial horizons 
Heliostat