Wednesday, April 24, 2024

Eclipse Prediction 1680

A 1680 eclipse prediction?

It has been much in the news lately that Edmond Halley (1656-1742) was the first in modern times to predict an eclipse with modern methods, specifically the 22 April 1715 eclipse across southern England. Discussing this with University of Arkansas physicist Daniel Kennefick over the last couple of weeks, it seemed strange that Isaac Newton (1642-1727) did not predict, nor much mention, eclipses in his great book, the 1687 Principia Mathematica. As some of you know, I collect early science books and this set me searching through some works likely to address the eclipse problem. There were several promising dead ends: 

1706, Ditton, Institution of Fluxions 
1716, Whiston, Newton’s Mathematick Philosophy 
1728, Pemberton, A View of Newton’s Philosophy 
1730, Newton, Optics
1742, Maclaurin, A Treatise of Fluxions 

Then I took a chance on 1681, Jonas Moore, A New Systeme of the Mathematicks. This obscure book (only 14 North American collections hold a copy) is mainly an elementary text for schoolboys, sailors, and surveyors. Some chapters were written by Moore (1617-1679) and others were promised from his wide circle of friends.

Volume 1 chapter 7 dated 1680 is titled The Doctrine of the Sphere and the main preface attributes authorship to 'Mr. Flamsteed'. That would be John Flamsteed (1646-1719), first Astronomer Royal. The chapter preface is an interesting account of the history of eclipse prediction in 17th century England.

So move over Halley, Flamsteed predicted the 2 July 1684 England partial solar eclipse; and did it 30 years before your famous pamphlet predicting the 1715 event.





Thirty-Five years later, Edmund Halley published a prediction of the 1715 total solar eclipse superimposed on a map of England. Very cool, but Flamsteed could have done the same for the 1684 partial eclipse that he predicted.