TLS signed “A. Einstein,” one page, 8.5 x 11, personal letterhead, April 4, 1950. Einstein sends thanks for a sent photo of himself with noted astrophysicist Arthur Eddington, who wrote an article, Report on the relativity theory of gravitation, which announced Einstein’s theory of general relativity to the English-speaking world. In full, “I thank you very much for kindly sending me the photo your father took of the revered Eddington and myself, I cannot remember the exact year the picture was taken, but it must have been in May or June of either 1931 or 1932.” Accompanied by a carbon of the letter sent to Einstein, by Mary A. B. Brazier, presenting him with the photo and reminding him of his “visit to the Observatory at Cambridge” where the photo was taken. More incredibly, the original photo of Einstein and Eddington is included, with a notation written on the reverse “Taken by A. E. B.” In fine condition, with light mailing folds to letters. COA John Reznikoff/PSA/DNA and R&R COA.