Copy letter, from Sir John Herschel to Sir Charles Lyell, dated at Collingwood Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Comments on why John Frederick William Herschel gave 239 degrees F as the temperature of space. Geological specimens may be given to the Geological Society or to the Jermyn Street Museum. 5 March 1865