Orders missing issues of Astronomische Nachrichten. Answers HS's question about JH's essay on Physical Astronomy. James South's testimony 'vindicated' Josef Fraunhofer's repeating micrometer to Edward Troughton. C. F. Gauss's mode of determining powers of telescopes. Nothing heard of Captain [Maughan?]. Directions for sending [K. L.] 'Harding's atlas' to JH. Gives J. F. Daniell's address. Astronomical Society is gratified that HS dedicated book to it. Shall direct Robert Molyneux to send L. A. Fallon's clock to HS.