On November 6 1919, at a joint meeting of the Royal Astronomical Society and the Royal Society, held at London's Burlington House, the ‘lights went all askew in the heavens'. That, anyway, was the rhetorical flourish with which the New York Times hailed the announcement of the results of a pair of astronomical expeditions conducted in 1919, after the Armistice but before the official end of the first world war. One expedition, led by Arthur Stanley Eddington, assistant to the Astronomer Royal, had repaired to the plantation island of Principe, off the coast of West Africa; the other, led by Andrew Crommelin, who worked at the Royal Greenwich Observatory, headed to a racecourse in Brazil.