A wallet of J F B Oppen mapping instruments, Danish, dated 1795 and 1807, signed J F B Oppen, The red leather book-form case with gild tooling opening to printed page and opposite two dividers with circular silver dials and separate arc with linear scales, the centre section with pages now removed and rear section with hand coloured chart of the coast near Copenhagen, 18.5 x 11 x 1.5cm (7 1/4 x 4 1/4 x 1/2in) Footnotes: Oppen's full name was Johan Frederik Blix Oppen and it appears that he was a Danish military engineer. The quotation on the inner cover comes from L'art de la guerre by Frederick II, king of Prussia, known as the philosophe sans-souci, the name of a castle is that that the one he built himself. For further information on this lot please visit Bonhams.com For further information about this lot please visit the lot listing