Storm Van's Gravesande - 1750. S 91 55 2. 60. Map of the Orinico - Essequibo Region, Handed to the West India Company by Governor Storm Van's Gravesande, June 22, 1750. Reproduced fromm the Manuscript Copy on Parchment in the Rijksarchief at te Hague, No. 1496 of the Catalogue. Photo. Lith. by A. Hoen & Co., Baltimore, MD.