1. IOR/V/19/6 Reference (shelfmark): IOR/V/19/6 Title: Account of the Operations of the Great Trigonometrical Survey of India, Vol 5, Details of the pendulum operations by Captains J.P. Basevi and W.J. Heaviside and of their reduction. J.T. Walker. Dehra Dun, 1879 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1879 Extent: 1 volume