Rare separately issued chart of the region from Korea and Japan in the North to the Philippines and Borneo in the South, centered on Hong Kong and Formosa (Taiwan), focusing on the prevailing currents and winds, as observed by Matthew Fontaine Maury, then serving as Lieutenant in the U.S. Navy.
The map tracks the the various voyages of the American and other ships which surveyed the region and took measurements as part of Maury's landmark project.
Maury's seminal work on the Oceans currents and related atmospheric phenomen was commenced in 1847, with the publication of his map of the currents of the North Atlantic (Schwartz & Ehrenberg 278) and culminated with The Physical Geography of the Sea, published in 1855. While preparing the charts Maury sought the cooperation of mariners from many nations, getting them to report to him their regular observations of winds and currents, which he either added or corrected on his own charts.
This was the Age of the great Clipper Ships, and their masters prized Maury's charts as by following their wind and current directions, they were able to cut many days off their voyages from North American ports to the Far East, as also the Clippers racing to and from New York and San Francisco.
Maury was the chief Naval Officer in charge of charts from 1843 to 1861. His work describing seasonal winds and currents was conceived largely outside conventional academic circles. Maury was made an honorary member of the Boston Marine Society, where his portrait was hung, and later turned upside down when he later elected to join the Confederacy during the American Civil War.