In 1736, an 80-year-old Edmond Halley, dignified by the academic robes of his alma mater, Queens College Oxford, sat down at the brush of transplanted Swedish artist Michael Dahl for his final official portrait.1 By the time he posed for Dahl, Halley occupied a rank of distinction among practical philosophers of the early Enlightenment. His manifold achievements included authorship of the first catalogue of stars in the Michael Dahl, “Dr E Halley, Aged 80.” © The Royal Society. southern hemisphere, the (...) laying of actuarial foundations for life insurance and annuities, his correct prediction of the return in 1758, 1835, and 1910 of a bright periodic comet that today bears .. (shrink)