Nicolas Louis de Lacaille - Principal Works

Astronomer, born in Rumigny, NE France. From 1750 to 1754 he led an expedition to the Cape of Good Hope, where he was the first to measure the arc of the meridian in South Africa, compiled a catalogue of nearly 10 000 S stars, Coelum Australe Stelliferum (1763, Star Catalogue of the Southern Sky), and introduced 14 new S constellations.

Abbé Nicolas Louis de Lacaille (March 15, 1713 – March 21, 1762) was a French astronomer.

He is noted for his catalogue of nearly 10,000 southern stars, including 42 nebulous objects.

Born at Rumigny, in the Ardennes, left destitute by the death of his father, who held a post in the household of the duchess of Vendôme, his theological studies at the College de Lisieux in Paris were undertaken at the expense of the duke of Bourbon.

After he had taken deacon's orders, however, he concentrated on science, and, through the patronage of Jacques Cassini, obtained employment, first in surveying the coast from Nantes to Bayonne, then, in 1739, in remeasuring the French arc of the meridian, for which he is honored with a pyramid at Juvisy-sur-Orge.

His desire to observe the southern heavens led him to propose, in 1750, an astronomical expedition to the Cape of Good Hope, which was officially sanctioned. Among its results were determinations of the lunar and of the solar parallax (Mars serving as an intermediary), the first measurement of a South African arc of the meridian, and the observation of 10,000 southern stars.

Lalande said of him that, during a comparatively short life, he had made more observations and calculations than all the astronomers of his time put together.

La Caille crater on the Moon was named after him in 1961.

Principal Works

Astronomiae Fundamenta (1757), containing a standard catalogue of 398 stars, re-edited by F. Maraldi), giving zone observations of 10,000 stars, and describing fourteen new constellations Observations sur 515 étoiles du Zodiaque (published in t. of his Ephémérides, 1763) Leçons élémentaires de Mathématiques (1741), frequently reprinted ditto de Mécanique (1743), &c. Calculations by him of eclipses for eighteen hundred years were inserted in L'Art de vérifier les dates by Benedictine historian Charles Clémencet (1750) he communicated to the Academy in 1755 a classed catalogue of forty two southern nebulae, and gave in t. of his Ephémérides (1755) practical rules for the employment of the lunar method of longitudes, proposing in his additions to Pierre Bouguer's Traité de Navigation (1760) the model of a nautical almanac.