“Astronomer Edward Charles Pickering’s Harvard computers” by Harvard College Observatory – http://bookhistory.harvard.edu/takenote/sites/default/files/attachments/Computers_1890.jpg. Licensed under Public Domain via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:Astronomer_Edward_Charles_Pickering%27s_Harvard_computers.jpg#/media/File:Astronomer_Edward_Charles_Pickering%27s_Harvard_computers.jpg