Page 664 - 89 history of astronomy_opt

[20] For a different explanation see Sir
W. Huggins’s lecture, Royal Institution, May
13th, 1892.
[21] For the early history of the propos-
als for photographic cataloguing of stars,
see the Cape Photographic Durchmusterung ,
3 vols. ( Ann. of the Cape Observatory ,
vols. in., iv., and v.,

664