London: James Wyld, 1840. unbound. Map (diptych). Engraving with hand outline. Each image measures 23" x 23", northern page measures 23" x 26.25", southern page measures 27.5" x 23"
Beautifully detailed large scale double hemispheres, showing views from each pole. Some areas near the poles have not yet been fully explored. Unusually, Northern sheet is oriented horizontally while the Southern sheet is oriented vertically. Bottom edge of each plate is cutoff, but is original. Northern sheet has minor acid burn along edges, top edge is a little worn; image is unaffected.