1. IOR/V/27/420/88 Reference (shelfmark): IOR/V/27/420/88 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: Bengal and Assam 1899-1902. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume