Descartes, however, in his retirement at Stockholm, plainly cherished the impression that Roberval’s intimacy with Pascal prevented the latter from doing full justice to his scientific position and suggestions; and having as yet heard nothing, in June 1649, of the special results of Pascal’s experiments on the Puy de Dôme in the preceding year, he wrote to his friend Carcavi to let him know about these.
“I pray you, let me know of the success of an experiment which Pascal is said to have made on the mountains of Auvergne. . . . I had the right to expect this of him rather than of you, because it was I who advised him two years ago to make the experiment, and who assured him that, although I had not made it, I had no doubt of its success. But *as he is the friend of M. Roberval*, *who professes not to be mine*, *I have some reason to think he follows the passions of his friend*.” 12
That letter was immediately communicated to Pascal by Carcavi, who was his intimate associate no less than Roberval. But it seems to have elicited no reply. Bossut13 says that he despised it. On the other hand, Descartes’s biographer and eulogist, Baillet, blames Pascal for having carefully kept out of view Descartes’s name in all the accounts of his discoveries; and produces an array of passages from Descartes’s letters, showing page 43plainly that his mind was in the line of discovery finally