Copy letter, from Sir John Herschel to Edward Sabine, dated at [Collingwood] Copy of a letter. Thanks Edward Sabine for receipt of information about magnetic curves and the work of [A. D.] Bache. John Frederick William Herschel is glad to hear Edward Sabine is back to active work again, but John Frederick William Herschel says he is too ill to go to the B.A.A.S. meeting [in Aberdeen]. 1858 to 1859