Cross-currents in astronomy and navigation: Thomas Hornsby, FRS (1733-1810)

Thomas Hornsby was a hard-working, scientifically ambitious and significant man of vision (in more senses than one) during the second half of the eigh teenth century. He was a notable astronomical observer, founder of the Radc liffe Observatory at Oxford, a successful lecturer, a Commissioner of Longi tude at a critical time, and editor of James Bradley's Astronomical Observa tions. This paper presents some long-neglected facts; in assembling scatter ed fragments into a coherent account, it raises new speculations.