1. IOR/V/27/420/87 Reference (shelfmark): IOR/V/27/420/87 Title: India. Survey of India, Trigonometrical Branch Spirit-Levelled heights: Calcutta 1894-95. Dehra Dun, 1863-1903 Collection Area: India Office Records and Private Papers Languages: English Date Range: 1863-1903 Extent: 1 volume