Borrowed Perceptions: Harriot's Maps of the Moon

Drake Stillman , “Galileo's First Telescopic Observations”, Journal for the history of astronomy, vii (1976), 153–68.

For a previous reproduction and discussion of this map see Shirley John , “Thomas Harriot's Lunar Observations”, in Science and history: Studies in honor of Edward Rosen, Studia Copernicana, xvi (1977).

Stevens Henry , Thomas Harriot, the mathematician, the philosopher and the scholar (London, 1900), 116. See also Rigaud Steven J. , ed., Supplement to Dr. Bradley's Miscellaneous works (Oxford, 1833), 25.

Stevens , Thomas Harriot, 116.

Heydon to Camden William , 6 July 1610. In Rigaud , Supplement, 27.

Stevens , Thomas Harriot, 117.

Drake , “Galileo's First Telescopic Observations”, 159. Galileo suggests in the Sidereus nuncius that he used a 30-power telescope, but Drake argues convincingly that the drawings were based on a 20-power telescope.

Gingerich Professor , private conversation. This “leap of the imagination” characterized a great many astronomical discoveries during the seventeenth century. See Gingerich Owen , “Dissertatio cum Professore Righini et Sidereo Nuncio” in Bonelli M. L. and Shea William R. , Reason, experiment, and mysticism in the Scientific Revolution (New York, 1975), 77–88.

Another situation in which Harriot is known to have borrowed from a contemporary is discussed in North John , “Thomas Harriot and the First Telescopic Observations of Sunspots”, in Shirley John W. , ed., Thomas Harriot, Renaissance scientist (Oxford, 1974), 129–65. Harriot's initial observation of sunspots was made independently of Galileo, in December 1610. The early drawings, which show the spots as being discrete dark splotches, suggest that Harriot did not fathom the nature of the spots at this time. However, in a series of illustrations dated a year later, by which time Fabricius had published his De maculis in sole observatis asserting that the spots were cloudlike and located on the surface of a rotating Sun, Harriot depicts the spots as nebulous blemishes. Here, again, we find that Harriot had not independently grasped the significant aspects of the phenomena being observed.