Footnote:
Two important and well-documented studies on these issues are:
John Earman and Clark Glymour, "Relativity and Eclipses: The British Eclipse Expeditions of 1919 and Their Predecessors", Historical Studies in the Physical Sciences 11 (1980), pp. 49-85.
Klaus Hentschel, “Einstein’s Attitude towards Experiments: Testing Relativity Theory, 1907-1927”, Studies in History and Philosophy of Science 23 (1992), pp. 593-624.