Copy letter, from Sir John Herschel to Thomas Henderson, dated at London Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Rejoices to hear Thomas Henderson is a candidate for the Professorship of Astronomy at Edinburgh University. His astronomical work has been of great assistance to John Frederick William Herschel, especially his detection of the reasons for the error in the Greenwich Observations. 17 January 1829