A voyage in space; a course of six lectures "adapted to a juvenile auditory" delivered at the Royal Institution at Xmas 1913 (1915)
Turner, Herbert Hall, 1861-1930 · London Society for Promoting Christian Knowledge · leaf 126
r sort, and you mayknow the difference between good and bad lenses—with a good lens all the picture is in focus, with a poorone the edges show up fuzzy. Well, with a mirrorwe cannot help the edges being fuzzy, because wehave nothing we can alter. If we try to alter the JOURNEYING BY TELESCOPE 105… … Photograph showing very bad edges, though good in centre. way that has been already done for colour; a littlealteration in one can be accompanied by such a corre-sponding alteration in another that the edges ofthe field are improved while the centre is no worseoff. This way of setting one thing…
Astronomy -- Juvenile literature
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
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