| Description | Tables of comparative barometer readings from Captain Alexander Henning's barometer and a new standard barometer used by James Prinsep, Assay Master at the Calcutta Office. Observations made at 10.00am and 4.00pm during December 1838. Columns give information on: Captain Henning's barometer and thermometer; simple reading of Captain Henning's barometer; new standard barometer and thermometer, Mr. J. Prinsep's; new standard barometer simple reading, Mr. J. Prinsep's.
Signed [p.1]: 'John Curwin Off. I. Assay Master'. Endorsed [p.4]: 'Comparisons of Captn. Henning's Instruments with Standards of R.S. London J. Prinsep Esq. Calcutta'. |