1. IOR/L/E/7/1150, File 665 Reference (shelfmark): IOR/L/E/7/1150, File 665 Title: File 665 Survey of India: grant of an extension of service to Col C.H.D. Ryder, Surveyor-General of India Collection Area: India Office Records and Private Papers Languages: English Date Range: 28 Oct 1897-18 Feb 1923 Extent: 1 file