This large and very uncommon sea chart of the English Channel appeared in various collections of charts from Mount & Page's English Pilot. It is a later, amended edition, smaller than previous editions with additional text insets and nine coastal profile views across the top. The chart spans from the Isles of Scilly east to Dunkirk, with many places named along the southern coast of England and northern coast of France. In the Channel, there is a plethora of navigational information, including two compass roses, rhumblines, depth soundings, tidal figures, currents, bottom types, and more. This information is credited to Captain Edmund Halley. On two sheets, joined.

Edmund Halley (1656-1742) was an English astronomer, meteorologist, and physicist best known for calculating the orbit of the eponymous Halley's Comet. In 1686 Halley became the first to depict trade winds and monsoons on a map, which appeared on his untitled diagrammatic world map. Halley was granted temporary Captainship in the Royal Navy for his scientific voyage through the Atlantic on the ship Paramore, during which he investigated the laws governing the variation of the compass. He published his findings in General Chart of the Variation of the Compass (1701), a chart of the Atlantic ocean which was the first to use isogonic, or Halleyan, lines to show the pattern of magnetic variation. The following year Halley extended his chart to the western Pacific, using data from journals of voyages in the Indian Seas.

References: Shirley (BL Atlases) M.M&P-7a #2.

Condition: B

Issued folding on a lightly toned sheet with moderate staining, light scattered foxing, and an 11.5" fold separation at right that has been closed on verso with archival tape.