BORN, Max. [and] Sir Arthur Eddington. On the Quantum Theory of the Electromagnetic Field [and] The Masses of the Proton and Electron.
London: The Royal Society, 1934. All first editions.

Two papers in: Proceedings of the Royal Society, Series A, Vol. 143, No. 849, pp.410-37 and 327-50. Some chipping and small tears to spine strip. Otherwise fine.