Letter from George Adolph Erman, Berlin to Edward Sabine Discussion regarding the report of the British Association. Erman is aware of Sabine’s intentions to publish in the report ‘fragmentary words which accompanied first part of calculative results’ that Erman ordered and executed for the ‘construction’ of Sabine’s magnetic maps. Erman hopes that the full report to the British Association will refer to his and Mr Petersen’s new calculation of Gaussian constant as an explanation. Refers to the construction of the maps. 16 November 1871