1. RP 6711/2 Reference (shelfmark): RP 6711/2 Title: Scope & Content: HUMBOLDT, Alexander von. Autograph Letter Signed to an unidentified correspondent, recommending to his correspondent the engineer Girard. Sotheby’s, 5 Dec 1997, Lot 268 Creation dates: 20 July 1818 Collection Area: Western Manuscripts Languages: Undetermined Date Range: 13 Feb 1998 Extent: 5 photocopies