| 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', 'Incli- arc' [inclinometer], later induction in arc and induction [magnetometer] corrected, 'S.H.F.' [small horizontal force magnetometer], attached thermometer readings, and Gottingen mean time.
The front cover is inscribed: 'Small Instruments August 1846'. |