Short answers, pulled from the story.
The Moon passed directly between Earth and the Sun on Thursday, the 29th of May 1919. This event created a total solar eclipse with a magnitude of 1.0719 that lasted six minutes and fifty seconds at its peak.
The path of totality stretched from southeastern Peru across northern Chile and moved through central Bolivia into Brazil after sunrise. The shadow then crossed the Atlantic Ocean to reach south central Africa before ending near sunset in eastern Africa.
Photographs taken by British expeditions proved that the Sun's mass shifted how starlight bends when passing nearby. The amount of bending matched exactly what Einstein demanded in his generalized theory of relativity.
Sir Dyson organized two British expeditions to capture images during this eclipse. Sir Arthur Eddington led one group to the island of Príncipe while Andrew Claude de la Cherois Crommelin and Charles Rundle Davidson went to Sobral in Brazil.
A thunderstorm happened during the morning of the eclipse day and it had been overcast for many days beforehand on both expedition sites. Only thirty minutes before the eclipse did the clouds begin to dissipate yet astronomers took photos through gaps in the clouds.