| Description | Daily readings of magnetometers at hourly intervals made at the Colaba Observatory. On amended printed sheets, with columns for: 'S.D. in arc', [small declination magnetometer], 'L.D. in arc', 'Inclinometer in arc', corrected induction in arc, 'Small H.F.' [horizontal force magnetometer], attached thermometer readings, and Gottingen mean time.
The front cover is inscribed: 'Readings of Small Instruments fro the month of September 1846'. |