Rare separately published sailing chart of the English Channel, published by the French Royal mapmaker Jean Beaurain in 1760.
The map is ringed with various scientific objects and diagrams, including:
- The offshore and tidal currents and their visual representation on the chart with arrows.
- Ancient and modern nautical logs (used to approximate the speed of a vessel over water).
- The use of the mariner's crosstaff (l'Arbalestre) for measuring the altitude of the sun.
- The ship's wake or 'sillage'.
- The sounding lead (la sonde) for measuring water depth and the composition of the sea floor.
- The planisphere and a description of the earth's rotation.
- A simple astrolabe.
- The compass and compass card.
This is the first edition of the map. The second edition, issued in 1778, is far more common.