Copy of draft letter, from Sir John Herschel to John William Lubbock, dated at Collingwood Copy of draft letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. About the barometric formula for the measurement of heights. Herschel does not possess the Transactions of the Astronomical Society, which contains John William Lubbock's paper. Had to limit the scope of his article so could not deal with the point mentioned in John William Lubbock's letter. Comments on P. S. Laplace's formula. 14 September 1861