D O C . 1 5 5 C A L C U L A T I O N S 2 8 1 Published in Die Naturwissenschaften 14 (1926): 223–224. A manuscript is also available ([1 051]). [1]He presented the abstract of the paper to the Prussian Academy of Sciences on 7 January 1926 (see the preceding document). [2]Baer 1860. [3]Ludwig Prandtl noted in Prandtl 1926 that the meandering of rivers had been discussed in Thom- son 1876 and Isaachsen 1896 and 1911. R. A. Alpher and R. Herman also found precursors in Mottsmith and Langmuir 1922 (Alpher and Herman 1960). For details, see Illy 2012, pp.10–14. 155. Calculations [Berlin, on or before 7 January 1926] ____________________________________________ AD. [1 050.1]. Written on the left half of the draft for item 3 in Doc. 153. ∂xn ∂ ∂Γkl ∂xm ---------- ∂Γkm ∂xl ------------ – _________________ __________________ gilGkm gkmGil gimGkl – gklGim – + gil∂xnkm ∂G gkl∂xnim ∂G – gkm∂xnil ∂G gim∂xnkl ∂G – gim¨ ∂xl ∂Gkn ∂xn ∂Gkl· – © ¹ ¸ § gkm¨ ∂xn ∂Gil ∂xl ∂Gin· – © ¹ ¸ § + gin¨ ∂xm ∂Gkl ∂xl ∂Gkm· – © ¹ ¸ § gkn¨ ∂xl ∂Gim ∂xm ∂Gil· – © ¹ ¸ § + gil¨ ∂xn ∂Gkm ∂xm ∂Gkn· – © ¹ ¸ § gkl¨ ∂xm ∂Gin ∂xn ∂Gim· – © ¹ ¸ § + i l ohne Spezialisierung Dann normieren. = Gknm Gkmn δkmGnαα – δknGmαα + – Gknm Gkmn Gknm Gkmn –+ – +4Gkmn 4Gknm – Gknm – Gkmn δkmGnαα – δknGmαα + +