| Description | Contains letter related to the British colonial and Indian magnetic observatories, and the correspondence of their several directors with Professor Humphrey Lloyd, and many of his replies conveying instructions. Includes correspondence regarding magnetic work at observatories in Toronto, Cape of Good Hope, St Helena, Tasmania, Lucknow, Thiruvananthapuram (Trevandrum), Madras [Chennai], Singapore, Simla and Makerstoun. Chief correspondents include Humphrey Lloyd, Charles James Buchanan Riddell, Frederick Marrow Eardley-Wilmot, John Henry Lefroy, William James Smythe, Joseph Henry Kay, Richard Wilcox, John Caldecott, Samuel Owen Edgar Ludlow, Charles Morgan Elliot, E Russell, John Allan Broun, and James Clark Ross. |