Cercle hydrographique, known as "de Borda", in partially blackened brass and silver-plated graduated ribbon, with turned wooden grip. Unsigned. Marked "H.S. 805". Diameter: 27 cm. Wear, scratches, a few stains and oxidation. In a walnut case, with brass side handle, with accessories (wear, numerous scratches and bumps, cracks and a few chips; oxidation; front plate missing; some accessories missing).