| 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' [large declination magnetometer?], inlinometer and corrected induction [magnetometer], 'S.H.F.' [small horizontal force magnetometer], attached thermometer readings, and Gottingen mean time. |
| Place origin | Colaba Observatory, Bombay [Mumbai], India |