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 113
nks,like a long thin box ; that was the way some of themwere made), but that a single plank would suffice,if only a lot of circular diaphragms were attached to 92 A VOYAGE IN SPACE the plank at intervals. His whole invention was tosave three of the four planks and use one only !Perhaps I am not… … Fig. 23. these machines, so that astronomers cast about forsome other way of getting over the difficulty ofcolour. It occurred to several people independentlythat if a mirror could be used instead of a lens tobring the light to focus there would then be nocolour and therefore no difficulty. We will…
Astronomy -- Juvenile literature
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
