Copy letter, from Sir John Herschel to William Whewell, dated at 32 Harley St. Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Suggests revisions William Whewell should make in his paper in the 2nd ed. of John Frederick William Herschel's Admiralty Manual so as to make it more consistent with Frederick Beechey's. 4 February 1851