Astronomy for the use of schools and academies (1882)
Gillet, J. A. (Joseph Anthony), 1837-1908, Rolfe, W. J. (William James), 1827-1910 · New York : Potter, Ainsworth, & Co. · leaf 172
Fig. 165. telescope beside that of the spectrum. One of the simplest of these methods is shown inFig. 166. A is the telescope, B the collimator, and C the 154 ASTRONOMY. micrometer tube. The opening at the outer end of C con-tains a piece of glass which has a micrometer scale markedupon it. The…
Astronomy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.