1. IOR/L/E/7/1520, File 6697 Reference (shelfmark): IOR/L/E/7/1520, File 6697 Title: File 6697 Instructions as to the Survey of Navigation Lights and Sound Signals Collection Area: India Office Records and Private Papers Languages: English Date Range: 24 May 1927-19 Jan 1933 Extent: 1 file