3 6 4 D O C U M E N T S 4 2 4 , 4 2 5 J A N U A R Y 1 9 2 3 Best regards to your gracious wife! 423. From Sergei F. von Oldenburg[1] [Petrograd, 18 January 1923][2] [Not selected for translation.] 424. To Edgar, Else, and Edgar Michel Meyer[1] Colombo, 20 January 1923 Dear Meyers altogether! Japan was magnificent. Intelligent, fine fellows and in addition fine painting and architecture. Then Southeast Asia,[2] now Ceylon with interesting experiences. It’s onward now to Palestine, Spain, and then back home. Warm regards, yours, A. Einstein. 425. “On the General Theory of Relativity” [Einstein 1923e] Completed 22 January 1923 Presented 15 February 1923 Published 12 March 1923 In: Preußische Akademie der Wissenschaften (Berlin). Sitzungsberichte (1923): 32–38. § 1. Generalities. Formulation of the Field Equations The general theory of relativity’s mathematical structure was originally completely based upon the metric, i.e., on the invariant[1] . (1) [p. 32] ds2 gμνdxμdxν =