Stars and telescopes; a hand-book of popular astronomy founded on the 9th ed. of Lynn's Celestial motions (1901)
Todd, David P. (David Peck), 1855-1939, Lynn, William Thynne, 1835-1911 · Boston, Little, Brown · leaf 410
e objective was found so nearly satis-factory that only twenty minutes were required to ren-der it sensibly perfect. In this achromatic glass, withthe flint lens in advance of the crown, with a spaceof oin.i between them, a variation of this latter dis-tance will effectively correct the objective… … A MODERN CAMERA KOR STELLAR PHOTOGRAPHY(With equatorial mounting designed by Heyde) with the calculated value, which is often a markedadvantage. The effect of focal length upon the performance ofa lens is excellently shown by the wonderful photo- 35^ Stars a fid Telescopes graphs of the Milky Way…
Astronomy
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
