This is an interactive (javascript/html5) network graph that I partially coded in order to illustrate the flow of information in the Herschel household's observatory, during their deep-sky observations of 1783-1802. Michael Hoskin, who has called this sky survey "One of the greatest observing campaigns in the history of astronomy," relates several different descriptions of the observatory's workflow on pages 92-5 of Discoverers of the Universe (Princeton: Princeton University Press, 2001).

From these descriptions, we can assume the following organization of the observatory's people and apparatuses: the twenty-foot telescope rested on an a-frame mount; William sat on an elevated platform, looking through the eyepiece; a hired man stood at the base of the frame, to control the telescope's vertical and horizontal motions, per William's commands, given by bell; Caroline remained indoors, seated in a lit room, surrounded by instrumentation, reference materials, and her logbook of recorded observations. Her desk faced a window that opened towards the telescope, through which she shouted information to William as he needed it, and in turn received his observations as he made them.

J. A. Bennett provides relevant information on the means by which William was able to control the telescope's vertical motions: at different points in their observing campaign, different contrivances were used to determine the polar distance. Bennett reports that Caroline had direct access to declination readings starting January 20, 1784. (See Bennett, "'On the Power of Penetrating into Space': The Telescopes of William Herschel," Journal for the History of Astronomy, vol. 7 (1976), 87-8).
[Many thanks to Professor Hoskin, who directed me to Bennett's article in response to an inquiry on the subject.]

Roll your mouse over the nodes on the graph to see the information flow from any given person/apparatus.

  • Blue: outbound communications
  • Red: inbound communications



Credits: