Uncommon first edition of Matthew Fontaine Maury's rare separately issued chart focusing on the prevailing trade winds of the Atlantic Ocean. The map was produced for vessels to identify the best location to catch the trade winds and avoid the calms of the horse latitudes at any time of year.
This meticulous chart is intended to locate and describe the various trade winds of the Atlantic Ocean. The map presents three variables to show the strength of winds at various latitudes (horizontal lines) and longitudes (vertical darkened lines), at each month (vertical lighter liens). The number of measurements taken and the strength of the winds are indicated via numbers and numerals. While very complicated, this ingenious idea was important for expediting shipping across the Atlantic and is described in the text underneath the title.
The chart was originally issued in January 1851 (this example) and reprinted throughout the 1850s.
Lieutenant Maury's Work on Hydrography
Maury's seminal work on the Oceans currents and related atmospheric phenomena 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. By following their wind and current directions, they were able to cut many days off their voyages from North American ports to Europe and Asia, as well as from New York to 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.