Copy of letter, from Sir John Herschel to Edward Sabine, dated at Slough Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Expresses great pleasure that the fixed observatories have received official approval and financial support. Approves of Edward Sabine's cost estimates. Encloses copy of the B.A.A.S. memorial. Agrees to tell Humphrey Lloyd to order instruments as requested by Edward Sabine. 12 April 1839