The distance of stars in the 18th century: The scale of magnitude of John Michell (Q1582474)

Reverend John Michell (1724-1793) published in 1767: ``An Inquiry into the probable Parallax, and Magnitude of the fixed Stars, from the Quantity of Light which they afford us, and the particular Circumstances of their Situation'', Philos. Trans. 57, 234-264. This paper, together with his other papers on magnetism and geology is important and at the same time fairly neglected. The author of the present paper gives a brief exposition (without much attention to other astronomers) of the results in this area, starting with earlier measures of brightness and magnitude of stars. In spite of the difficulties involved in measuring brightness of stars, Michell constructed results in this area that are of amazing precision and rigor and his methods are described here. This is superimposed with the precision of the methods of Pierre Bouguer (1698-1758), whose methods Michell utilized. The author also explores Michell's successful efforts in presenting and disseminating his results.