Letter from Balfour Stewart, Kew Observatory to Edward Sabine Mr [Charles] Chambers has looked over Mr [John] Welsh’s observations and ‘finds the method quite correct’ apart from an exception. Stewart will make observations with the dip circle intended for [Colonel] Smythe. Stewart took the nine-inch Robinson and nine-inch Barrow to Barrows along with Captain Blakiston’s [azimuth] compass. 5 January 1860