His experiences there are set down in Kriegsgefangen Erlebtes 1870 ( 1871 ) ; subsequently he published his observations on the campaign in Der Krieg gegen Frankreich 1870-71 ( 1874-1876 ) . He set down his experiences in Kriegsgefangen Erlebtes 1870 ( 1871 ) and published his observations on the campaign in Der Krieg gegen Frankreich 1870-71 ( 1874-1876 ) .