EINSTEIN, The Meaning of Relativity, 1955

Fifth and last expanded edition by Einstein.
Popular work, published from his Stanford courses, which gives an overview of the theory of relativity. Published shortly after his death, this fifth edition presents for the first time the latest revision of Einstein's Theory of Gravitation.
"Shortly before his death Mr. Einstein completed a revised version of his Generalized Theory of Gravitation in which he felt he had succeeded in simplifying the derivations as well as the form of the field equations. The whole theory thereby becomes more transparent without changing its content . This simplified version is now presented here for the first time as Appendix II on the Relativistic Theory of the Non-Symmetric Field.".