Rare three-part world map from the first American encyclopedia

Rare map engraved by William Barker that appeared in the scarce first American edition of the Encyclopedia Britannica, known as Dobson's Encyclopedia. It shows the world divided in three parts: two polar projections and cylindrical projection showing the tropical regions. The South and North Pole are covered with the "Southern Icy Ocean" and "Northern Icy Ocean" respectively. The map focuses on the discoveries made by James Cook in the South Sea during his second voyage and the unsuccessful attempt by Phipps to reach the North Pole. The islands discovered by Kerguelen (named Kerquelin) are also indicated.