his stay in Marseille ( watching the same stars that Pythéas had observed in the same city five centuries ago and those of other astronomers for century's had also observed) that the tilt on the axis of earth was not constant all the time. Voltaire was the witness after the other enlargement of time scales given by the work of Louville. "This astronomer in 1714 went to Marseille to observe the eclipse as it had been set by Pythéas approximately 2000 years before ; he found in less than 20 minutes , it is to say in 2000 years, the eclipse, according to him it was approaching the equator by 3 degrees ( its assumed). Besides the movements he knew the sun would have another movement where it would turn on itself from one pole to another. This finding showed that in 23000 years the sun will be directed towards the equator and that in 2 million years all the climates around the world under the torrid zones and under the glacier zones will change” (Voltaire) Louvilles thesis explained mathematically by Euler, and accepted today, had a considerable echo but he was still challenged by other scientists. The Hire and Riccioli were reluctant. The observations from ancient Greeks, Arab-Muslim, ancient Chinese and the west search to add ideas. The crater Louville on the Moon is named after him. References 1732. Académie des Sciences. Archives, vol 3529., p. 131–136. Notes Bibliography Observations sur l'obliquité de l'écliptique, 1714 Nouvelles tables du soleil, 1720 Nouvelle méthode de calculer les éclipses, 1724 Remarques sur la question des forces vives, 1721–28. See also List of French astronomers 1671 births 1732 deaths 18th-century French astronomers 17th-century French mathematicians 18th-century French mathematicians French Navy officers Members of the French Academy of Sciences Fellows of the Royal Society French Army officers 17th-century French military personnel