ed
and forty-two of them, measured a degree of the meridian, and made
many observations of the moon--productive industry seldom equalled in
a single year in any field. These observations were of great service to
the astronomers, as they afforded the opportunity of comparing the stars
of the southern hemisphere with those of the northern, which were being
observed simultaneously by Lelande at Berlin.

Lacaille's observations followed closely upon the determination of an
absorbing question which occupied the attention of the astronomers in
the early part of the century. This question was as to the shape of the
earth--whether it was actually flattened at the poles. To settle this
question once for all the Academy of Sciences decided to make the
actual measurement of the length of two degrees, one as near the pole
as possible, the other at the equator. Accordingly, three astronomers,
Godin, Bouguer, and La Condamine, made the journey to a spot on the
equator in Peru, while four astronomers, Camus, Clairaut, Maupertuis,
and Lemonnier, made a voyage to a place selected in Lapland. The result
of these expeditions was the determination that the globe is oblately
spheroidal.

A great contemporary and fellow-countryman of Lacaille was Jean Le Rond
d'Alembert (1717-1783), who, although not primarily an astronomer, did
so much with his mathematical calculations to aid that science that
his name is closely connected with its progress during the eighteenth
century. D'Alembert, who became one of the best-known men of science of
his day, and whose services were eagerly sought by the rulers of Europe,
began life as a foundling, having been exposed in one of the markets of
Paris. The sickly infant was adopted and cared for in the family of a
poor glazier, and treated as a member of the family. In later years,
however, after the foundling had become famous throughout Europe, his
mother, Madame Tencin, sent for him, and acknowledged her relationship.
It is more than likely that the great philosopher believed her story,
but if so he did not allow her the satisfaction of knowing his belief,
declaring always that Madame Tencin could "not be nearer than a
step-mother to him, since his mother was the wife of the glazier."

D'Alembert did much for the cause of science by his example as well
as by his discoveries. By living a plain but honest life, declining
magnificent offers of positions from royal patrons, at the same time
refusing to grove