Biography of Nicolas Lacaille

Angie Aramayo

Astronomy Per. 1

Mr. Percival

8 Jan. 2014

Biography of Nicolas Lacaille

            The French astronomer, Nicolas Lacaille, was known to be “the father of the southern astronomy”. Not just because of his great accomplishments in the Cape of Good Hope but also because of the impact he has made to the concept of astronomy during the 1730s.

            As a child Nicolas Lacaille stood out from the rest of his peers. His intelligence and maturity made him an outstanding student. Due his father’s wealth he was well educated and raised. During his teens he had the support from the Duke of Bourbon because of how remarkably well he was doing at school. Many that looked up to him called him abbé even though he did not practice as a clergyman. After exceling in school, Lacaille became involved at an observatory in Paris with Jacques Cassini. There he made his first astronomical observation. However, it was during the eighteenth century when he became well known. European countries were having issues with the geodetics due to the rapid expansion of navigation. In order to dissolve these issues, Lacaille was assigned to map the seacoast. Soon after, he was assigned to verify the great meridian of France due to the excellent work he had done with his previous assignment.  His new assignment had to deal with the controversy between the Cartesian and the Newtonian theories. Lacaille had to either conclude whether the earth was a spheroid or an equatorial bulge type of sphere.  After months and months of measuring the lines of latitude at Bourges and Arles and improving Picard’s measurements, which were 1/1,000 too long, he finally concluded that the great meridian has degrees of latitude that increase in length as they approach the equator making the Newtonian theory true. This discovery was the complete opposite of what French astronomers had believed. Due to his success Lacaille became a famous astronomer and was paid to write books about his observations such as Leçons élémentaires de mathématiques, Leçons élémentaires d’optique, and Leçons élémentaires de mécanique.

Although Nicolas Lacaille experienced fame, he never stopped having curiosity over the sky. One of the many subjects he was most interested about was the southern stars’ invisibility from the latitude of Paris. This is when his expedition to the Cape of Good Hope started. Driven by curiosity, Lacaille found himself exploring the sky from the southern hemisphere. The reason why Nicolas Lacaille was popular among astronomers was because of the rapid pace he worked in and accomplishing his observations with limited resources. During his exploration at the Cape of Good Hope he was given a small room measuring twelve feet square and few materials. However, his small workspace and few utensils did not prevent him from measuring the solar and lunar parallax. He also discovered the right ascensions and declinations of 1,942 out of 10,000 stars seen from the southern sky. After finding the stars’ location in the sky Lacaille named constellations. Some of these constellations were Sculptor, Pyxis, and Octans. He accomplished all of this within one year. In his later years, Lacaille shifted his research towards comets, including Halley’s comet, and revising the books other astronomers have written about the sky.

What astronomers around Nicolas Lacaille’s time remember the most about him was not just his multiple observations and calculations he made during his career of twenty-seven years but also his sincere honesty and decency towards astronomy. Lacaille was a devoted astronomer who never lost his curiosity of the sky throughout his time of fame. It did not matter what type of telescope he had near by, he always had to observe the sky.