Copy letter, from Sir John Herschel to Gilbert Elliot, Second Earl of Minto, dated at 9 Downing St. Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Discusses the pros and cons of Gilbert Elliot, Second Earl of Minto's proposal that [J. C.?] Schenck, a Swiss maker of optical instruments, set up a business in London. John Frederick William Herschel is not sure that John Frederick William Herschel ascended Mt. Rosa, but is certain of John Frederick William Herschel's barometric reading. Interested in Gilbert Elliot, Second Earl of Minto's method of estimating air temperature. 16 June 1822