That is what we think now; but the light and frivolous women who constituted the leaders of society in Mme. du Chatelet's day, and who were devoured by envy and jealousy of one who was so much their superior in intellect were not so minded. Far from sympathizing with her work, they proved to be her most virulent critics and most pronounced enemies. Neither Moliere nor Boileau could have heaped more ridicule on the pedantic women of their time than was meted out to the translator of the _Principia_ by certain noble dames of provincial chateaux or by distinguished habituees of prominent Parisian salons. Thus the petulant _ennuyee_, Mme. de Stael, in a letter to her friend, Mme. du Deffand, writing of Mme. du Chatelet, who was then her guest at Sceaux, tells us that "she is now passing in review her principles. This is a task she performs every year, else they might, perhaps, make their escape and run to such a distance that she would never be able to recover any of them. I verily believe that they are in durance vile while in her possession, as they were certainly not born with her. She does well to keep a strict watch over them."[141] And, in her turn, Mme. du Deffand, who was wont to pose as the intimate friend of Mme. du Chatelet, did not hesitate to write and circulate a pen portrait of this friend--and that after the unhappy woman was in her grave--which for bitter reviling and brutal villification has probably never been equalled. A witty Frenchman observed of this portrait that it reminded him of an observation once made by a medical acquaintance of his concerning one of his patients: "'My friend fell ill; I attended him. He died; I dissected him.'"[142] Among other women astronomers of the eighteenth century who deserve mention are Mme. du Pierry, the Duchesse Louise of Saxe-Gotha, and Mme. Hortense Lepaute. According to Lalande, Mme. du Pierry was the first woman professor of astronomy in Paris. He dedicated to her his _Astronomie des Dames_, and incorporated in his own works many of her memoirs on astronomical subjects. She devoted much time to calculating eclipses with a view to accurately determining the motion of the moon, and was, besides, the author of numerous astronomical tables which exhibit patient research and unquestioned skill. The Duchesse Louise had a great reputation as a rapid and accurate computer, and was celebrated for the number and variety of her computations. Her modesty, however, prevented her from publishing anything or even having her work quoted. Considering, however, the amount and character of her work, the most eminent woman astronomer that France has yet produced was, without doubt, Mme. Hortense Lepaute, the wife of the royal clockmaker of France. She first distinguished herself by her investigations on the oscillations of pendulums of different lengths, an account of which is to be found in her husband's valuable work, _Traite d'Horlogerie_, published in 1755.