Sir Frank Dyson.
"Physics in Astronomy."
London, the Institute of Physics, 1928. 248x155mm, 15pp. Original wrappers, FINE copy. $95
"Sir Frank Watson Dyson, KBE, FRS FRSE was an English astronomer and Astronomer Royal who is remembered today largely for introducing time signals from Greenwich, England, and for the role he played in proving Einstein's theory of general relativity"--Wiki
"Sir Frank Watson Dyson, Astronomer Royal of Britain, conceived in 1917 the perfect experiment to resolve the issue. A total solar eclipse on May 29, 1919, would occur just as the sun was crossing the bright Hyades star cluster. Dyson realized that the light from the stars would have to pass through the sun’s gravitational field on its way to Earth, yet would be visible due to the darkness of the eclipse. This would allow accurate measurements of the stars’ gravity-shifted positions in the sky. Eddington, who led the experiment, first measured the “true” positions of the stars during January and February 1919. Then in May he went to the remote island of Príncipe (in the Gulf of Guinea off the west coast of Africa) to measure the stars’ positions during the eclipse, as viewed through the sun’s gravitational lens."--Wired
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