D O C U M E N T 2 5 7 A U G U S T 1 9 2 8 2 5 3 , which would be interesting only for the singular solutions . In the case of the coupled invariant,[3] one can, however, get through to the end. One finds there: then set: , obtaining simply: , and is in fact a solution, apparently even a physically satisfactory one. Yours truly, Müntz P.S.: Therefore, . 257. To Chaim Herman Müntz [Scharbeutz,] 21 August 1928 Dear Mr. Müntz, Hearty thanks for your two letters.[1] The centrally symmetric solution is based (unfortunately!) on a calculational error, by which the coupled field equation[2] for is not satisfied by the ansatz given above. It seems that there is no centrally symmetric electrostatic solution. Thus, the prospects for a physical in- terpretation of the theory are dim for the time being. I have looked again at the problem of motion in the original theory of gravity in order to generalize the method of deriving the law of motion for a serious assess- ment of field theories is possible only if one has mastered the laws of motion of the singularities.[3] I look forward to our being able to communicate verbally again. I still am of the opinion that distant parallelism must lead to something. Kind regards, your A. E. h 4 a 0 = h 4 a a j r = r 0 = h 4 a j r -- a = h 4 a a j-- r = h 4 a j x a 2r ------- - h4 a + = h4 a 0 h4 a a 0 = = h4 a 0 = h 4 a j------- x a 2r - = ha 4 j----a- x r = h – h , h , – h , + + 0 = a = 4 =