Documents comprising this collection can be classified under four headings: 1) Annual reports of the laboratory between 1848 and 1993 (100 volumes); 2) Observations made at the magnetical and meterological observatory at Bombay. These are also in the form of handwitten records (300 notebooks have been preserved); 3) Official correspondence of the Institute concerning the establishment of new observatories between 1837 and 1903; and 4) Rare books such as: 'Observations of Magnetic Declinations made at Trivandrum and Augustia Observatories,' by Augustia Malley and John Allen (sic) Brown (eds.), 1873. 580 pp.; 'Magnetical and Meteorological Observatories, 1871-1878,' Bombay.