A new & accurate chart of the world. Drawn from authentic surveys, assisted by the most approved modern maps & charts & regulated by astronl. observations, whereon are described lines, shewing the variation of the magnetical needle, according to observations made by several experienced navigators about the year 1744. By Eman: Bowen, Geographer to His Majesty. (London: Printed for William Innys, Richard Ware, Aaron Ward, J. and P. Knapton, John Clarke, T. Longman and T. Shewell, Thomas Osborne, Henry Whitridge ... M.DCC.XLVII)