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Beskrivelse
A geologist and fellow of the Royal Astronomical Society, Isaac Roberts (1829-1904) made significant contributions to the photography of star-clusters and nebulae. By championing reflecting rather than refracting telescopes, Roberts was able to perceive previously unnoticed star-clusters, and was the first person to identify the spiral shape of the Great Andromeda Nebula. Roberts' use of telescopes for photographing stars provided greater definition of stellar phenomena than previously used hand-drawings. Although Roberts' conclusions about the nature of the nebulae he photographed were not always correct, and sometimes misinterpreted by others, the book is significant for the possibilities it suggests for nebular photography. Published in 1893 and 1899, these volumes represent the summation of his work with his assistant W. S. Franks at his observatory in Crowborough, Sussex. Lavishly illustrated, the books contain descriptions of instruments and methodology, and Roberts' theory of the stars' origins and nature.