In 1704, Edmund finally received a well deserved academic appointment when he accepted the Savilian Professor of Geometry at Oxford when John Wallis died. This appointment upset Flamsteed even more. Established firmly in an academic setting, he now turned his attention fully to a work originally begun in 1682.
Armed with Kepler’s Laws of Planetary Motion, and Newton’s theories of elliptical orbit, Halley recognized that the comets of 1456, 1531, 1607, and 1682 all followed similar paths. He then deduced that these were all in fact, the same comet. After publishing his theory, "Synopsis on Cometary Astronomy", in 1705, it was a matter of waiting for the next return, to prove his theory.
After the death of John Flamsteed, Edmund Halley was his successor as Astronomer Royal. Flamsteed’s widow was so angry that she had all of her late husband’s instruments sold so Halley could not use any of them.
During his years of scientific study, Halley had many accomplishments. Despite his incorrect belief that the Earth was hollow and made up of concentric spheres, he was a brilliant man. In 1716, he conceived two different diving bells to make underwater exploration possible. Using the catalogs of Ptolemy, he deduced the motion of stars, measuring three. Studying the moon, he developed a method of determining longitude at sea and observed the moon through the 18 years of a complete revolution of its nodes. If that were not enough, he also studied archaeology, geophysics, the history of astronomy, and the solution of polynomial equations.
Edmund Halley died January 14, 1742 in Greenwich, England. He did not survive to see the return of the comet, which would later bear his name, on Christmas day in 1758. His "Tabulae astronomicae" was published 7 years after his death.
