Cercle hydrographique, "de Borda", in partially blackened brass with turned wooden handle. Unsigned. Inscribed "Dépôt de la Marine" and numbered 201. Diameter: 28.5 cm. Wear, scratches, stains and oxidation. In a walnut case, labeled "LENOIR, Ingénieur du Roi, à Paris" on the reverse of the lid, with accessories. Brass plate on front, engraved "Dépôt de la Marine, Cercle de réflexion, LENOIR, 201" (wear, scratches, bumps, play in assemblies and a few cracks and chips; some accessories missing).