The Longitude at the Eve of the Third...

Geneva, Hotel Des Bergues, Oct 23, 1999

LOT 514

Fait & Invenit par Charles Bloud, Dieppe (France), circa 1680.Fine rectangular ivory diptych sundial.The upper leaf with horizontal pin dial and engraved sprandels, the interior with a pewter lunar volvelle and annual calendar; lower leaf with inset magnetic compass, adjustable pewter chapter ring, paper compass rose and folding latitude arm, the underside with later brass silvered calendar scale for adjusting the chapter ring.Signed on the silvered calendar scale and the paper compass rose.Dim. 73 x 59 mm.