"A Map of the Cape of Good Hope & the Country adjacent", Gibson, John

Great little map of the region between St. Helena Bay and False Bay and Cape showing the early settlements, tribal lands, and terrain. Locates Swarte Land, Hottentot Holland, Frans Hoeck and more. Shows the triangulation from La Caille's survey of 1752. Nicolas Louis de La Caille (1713 - 1762) was a French astronomer who is remembered for his work to catalogue nearly 10,000 stars, including 42 nebulous objects. His numerous publications and accomplishments included the introduction of 14 new constellations and calculating a table of eclipses 1800 years into the future. On the moon the crater La Caille is named after him. At the Cape Lacaille wanted to test Newton's theory of gravity and thus verify the shape of the earth. In South Africa he setup a baseline north of Darling then measured a 90 mile arc of meridian between Cape Town and Aurora. His results suggested an egg-shaped earth. Over 80 years later Thomas Maclear, the Astronomer Royal at the Cape, repeated the measurements. He discovered the earlier measurements had failed to take account for the gravitational effect from the nearby mountains, thus restoring the earth to a proper oval shape. Decorative title cartouche at lower left. Distance scale is in the French units of Toises. Before France adopted the metric system in 1799 the toise was the French equivalent of the fathom and was used in both land measurement as well as to express water depth. Published in the November 1755 issue of the Gentleman's Magazine.

References: Jolly GENT-92.

Condition: B+

Fine dark impression with just a little variation in the age toning. Close margin at left as issued.