Halley's Eclipse: a coup for Newtonian prediction and the selling of science

300 years ago, on the 3rd of May 1715, a rare solar eclipse occurred over England. It was an opportunity too good to miss for those promoting new astronomical theories - and their own careers.

In 1715, 300 years ago today, a total solar eclipse was visible across a broad band of England. It was the first to be predicted on the basis of the Newtonian theory of universal gravitation, its path mapped clearly and advertised widely in advance. Visible in locations such as London and Cambridge, both astronomical experts and the public were able to see the phenomena and be impressed by the predictive power of the new astronomy.

Wikipedia will tell you that this is known as Halley's Eclipse, after Edmond Halley, who produced accurate predictions of its timing and an easily-read map of the eclipse's path. Halley did not live to see the confirmation of his predictions of a returning comet - a 1759 triumph for the Newtonian system - but he was able to enjoy his 1715 calculations, which were within 4 minutes, and to improve on them with a corrected map (above). He observed the eclipse from the Royal Society's building in Crane Court on a morning with a sky of "perfect serene azure blew".

The like Eclipse having not for many ages been seen in the Southern Parts of Great Britain, I thought it not improper to give the Publick an Account thereof, that the sudden darkness, wherein the Starrs will be visible about the Sun, may give no surprize to the People, who would, if unadvertized, be apt to look upon it as Ominous, and to interpret it as portending evill to our Sovereign Lord King George and his Government, which God preserve. Hereby they will see that there is nothing in it more than Natural, and no more than the necessary result of the Motions of the Sun and Moon; And how well those are understood will appear by this Eclipse.