Report on the Relativity Theory of Gravitation

London: Fleetway Press, 1918. FIRST EDITION. Original wrappers. Fine. THE FIRST INTRODUCTION OF EINSTEIN'S GENERAL RELATIVITY TO THE ENGLISH-SPEAKING WORLD. The groundbreaking first edition (1918), with the second edition (1920), containing the account of Eddington's 1919 expedition proving Einstein's theory, both in original wrappers. "Einstein's discovery of the General Theory of Relativity was communicated to the Berlin Academy of Sciences in 1915. Because of the First World War, direct communication with physicists in Germany was not possible, but the papers were forwarded to Eddington, who was then Secretary of the Royal Astronomical Society, by Willem de Sitter, a personal friend of Eddington's in neutral Holland. The theory is of considerable mathematical complexity, but, as Einstein stated in the last paragraph of his paper, 'scarcely anyone who has fully understood this theory can escape from its magic'. Eddington was the ideal expositor of these ideas in English and within 2 years had written his Report on the Relativity Theory of Gravitation for the Physical Society of London" (Malcolm Longair, "Bending Space-time").

The second edition is notable for containing a new preface that discusses the results of the "eclipse expedition" led by Eddington that verified General Relativity and catapulted Einstein into world-wide fame. This preface precedes Eddington's full report in the Philosophical Transactions.

Provenance: Almost certainly Nobel Prize winning physicist's Charles Glover Barkla's copy of the 1918 report, with an original 1918 receipt in Barkla's name laid in. Barkla won the 1917 Nobel Prize in Physics "for his discovery of the characteristic Röntgen radiation of the elements".

London: Fleetway Press for The Physical Society of London, 1918 and 1920. Octavo, original wrappers; custom box. General light wear to wrappers. Beautiful copies. RARE.