Very scarce example of Joseph Nicholas De L'Isle's map showing the Russian Discoveries along the NW Coast of America in 1723, 1732, and 1741, the tracks of Bering's first and second voyages and of De L'Isle de la Croyere with Capt Tchirkow in 1741, the track of de Frondat's voyage of 1709, and the route of the Galleons in 1743. The discovery of Water of Wager in 1746 and 1747 is also show. The NW Coast of America is fictitious above Cap Blanc. The massive sea of the west is one if the earliest appearances of this mythical sea on a map. The map was first published by the Prussian Academy of Science & Literature. This example appeared in Swiss mathematician Joseph Von Euler's Atlas. Tooley 102A. A seminal map for NW Coast of America collectors. A nice example, in old color, of this very rare map.