This is a fine posthumous copper-plate portrait of the Rev'd Dr. Edmund Halley (1656-1742), the second Astronomer Royal (1720-1742). Halley is in many ways the father of the Transit of Venus enterprise, for he is the one who realized the practicality of using ToV observations to determine the Sun-Earth distance (the Astronomical Unit, AU), who devised a method for doing so (the so-called Halleyan Method), and who encouraged the mounting of a 1769 ToV campaign to that end, although he himself was unlikely to live to take part, or see the results. The plate is form our Archives' copy of Edmund Halley, Edmundi Halleii astronomi dum viveret regii tabulæ astronomicæ. Accedunt de usu tabularum præcepta, ed. Io. Bevis (Londini: apud Gulielmum Innys, MDCCXLIX). Image ©RASC.

Portrait of Edmund Halley