1711 Moll map of the World showing Trade Winds

 

courtesy of Geographicus

 This is Herman Moll's 1711 chart of world trade winds, an early example of a meteorological chart based on Edmond Halley's seminal 1686 map.

This first printing of the map is notable for reflecting the state of European geographic and scientific knowledge at the time, making new discoveries but with many uncertainties remaining, as with the coasts of Australia, New Zealand, and California.

 

Centered on the Pacific Ocean, the map is crisscrossed by lines representing the prevailing winds at various times of the year.

Arrows in 'void spaces' (especially the Pacific) demonstrate shifting trade winds.

The regularity of winds around the Indian Subcontinent and between Mainland and Insular Southeast Asia (i.e., the monsoons) indicates why these regions have carried on extensive maritime trade for many centuries.

The map is also notable for including a 'line of no variation' (agonic line), that is, a line where there would be no magnetic variation between north on a compass and true north, another important contribution of Halley (subsequent research has shown that this line is constantly moving due to fluid motion in the Earth's core).

This map is also significant for demonstrating contemporary cartographic debates.

The coasts of Australia, Diemen's Land (Tasmania), and New Zealand are partially mapped, based on Dutch explorations of the 17th century, but these would not be fleshed out until Cook's voyages some 60 years after this map's publication.

Also important is the mapping of California as an island - a convention Moll wholeheartedly embraced - just below and to the right of the title box.

The British Empire is noted on the east coast of North America leading to a surprisingly inaccurate, amoeba-like mapping of Cape Cod.

 

The present map is based on Edmond Halley's untitled 1686 map, commonly known as 'Halley's Chart of the Trade Winds,' that appeared in the journal.

Halley's original was centered on Africa and eschews the Pacific entirely, whereas Moll had placed the Pacific at center.

Moll has also extended the scope further north and south, and added the information about monthly and seasonal wind variations.

In other words, Moll has added significantly to Halley's original map, which is considered to be the earliest meteorological map.