A Chart of the Currents in the Indian Sea During the Southwest Monsoon, to the Northward of the Line


Jacques-Raymond Grenier (1736‒1803) was a French naval officer and hydrographer known primarily for his charts of the Indian Ocean. Grenier spent the years 1768‒69 and 1772‒76 exploring and charting the various islands in the Indian Ocean, particularly where the French had colonial possessions and interests. He wrote of his discoveries in his Mémoires de la campagne de découvertes dans les mers des Indes (Memoire of the explorations in the Indian Ocean) published in 1770. On the basis of Grenier’s discoveries of the currents and winds prevailing during the southwest and northeast monsoons in the Indian Ocean, he found more direct and hence faster routes to and from French colonial possessions in India, including the Coromandel Coast, and to the Strait of Malacca, decreasing the length of such voyages by about 3,200 kilometers. This map shows the route from the Isle de France (Mauritius) to the East Indies formerly used by French mariners, which went northwest past the tip of Madagascar and hugged the east coast of Africa before sailing east past Ceylon (Sri Lanka) to Sumatra. It depicts the currents and winds charted by Grenier and the new route he discovered, which involved sailing more directly north and then turning east before reaching the equator for the Strait of Malacca. The map was originally engraved by Jean Lattré in 1776 and was included in Neptune oriental by Jean-Baptiste d’Après de Mannevillette. This edition appeared in The Oriental Pilot, or, a select collection of charts and plans, both general and particular; calculated for the navigation of the country trade in the seas beyond the Cape of Good Hope, published for the English market by Robert Sayer and Jonathan Bennett in 1778.

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Robert Sayer and John Bennett, London


Title in Original Language

A chart of the currents in the Indian Sea during the northeast monsoon, to the northward of the line

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1 map


  • Map showing the currents in the Indian Ocean during the southwest monsoon. Includes the ancient course of the route to India. This plate is from: The Oriental pilot, or, A select collection of charts and plans ... for the navigation of the country trade in the seas beyond the Cape of Good Hope.

Last updated: January 3, 2018