Reviews Astronomical Spectrographs and their History by John Hearnshaw Share this: Share via email (Opens in new window) Email Click to share on Facebook (Opens in new window) Facebook Click to share on Reddit (Opens in new window) Reddit Click to share on X (Opens in new window) X Click to print (Opens in new window) Print By Science News May 8, 2009 at 1:53 pm Astronomers have used these instruments to explore the heavens since the 19th century. Cambridge Univ., 2009, 240 p., $140. ASTRONOMICAL SPECTROGRAPHS AND THEIR HISTORY BY JOHN HEARNSHAW