Copy of draft letter, from Sir John Herschel to John Henry Dallmeyer, 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. Is he acquainted with his ordinary reading glass? Gives details. Always carries a small one around with him for reading small print; thinks there would be a good market for them. 16 February 1867