{23b} Faugère, Lettres, Opuscules, etc., p. 452. It is difficult to make out the exact chronological sequence of some of the facts mentioned by Pascal’s sister and niece. But a special accession of ill-health, according to both, seems to have followed his conversion at Rouen, and to have been amongst the causes of his removal to Paris in 1647. {23c} Pp. 134–137. {26a} Jacqueline Pascal, p. 73. {26b} Œuvres de Blaise Pascal, t. 4. Paris, 1819. {28a} North British Review, August 1844, p. 296. {28b} I owe this information to the kindness of my friend, Professor Tait of Edinburgh. He further informs me that “of late years the calculating machine of M. Scheutz has been employed in the production of many valuable tables almost hopelessly beyond the power of mere mental calculation;” and that a very simple and ingenious machine, known as the Arithmomètre of M. Thomas, is to be found in the office of almost every engineer and actuary. {29a} Letter to M. Ribeyre, Œuvres, t. iv. {29b} The illustrious Italian was then advanced in years. He died in January 1642. {31} Œuvres, t. iv. pp. 160,161. {33} Sir D. Brewster, in an article on Pascal’s Writings and Discoveries in North Brit. Rev., Aug. 1844. Sir David’s account is almost literally translated from M. Périer’s letter to Pascal, of date September 22, 1648, and embodied in Pascal’s “Récit de la grande Expérience de l’Équilibre des Liqueurs,” first published in 1648. {39a} Cousin, Jacqueline Pascal, p. 94. {39b} “Evidently,” says Cousin, “M. Habert de Montmor, the Mæcenas of the _savants_ of the time.” {41} Blaise Pascal. Préface de la nouvelle éd., P. 46. Œuvres, t. i. 1849. {42a} Jus mihi esset hoc ipsum ab ipso potius quam a te expectare, ideo quod ego ipsi, jam biennium effluxit, auctor fuerim ejus experimenti faciendi, eumque certum reddiderim, nec de successu non dubitare, quamquam id experimentum nunquam fecerim. Verum quoniam D. R. amicitia junctus est qui mihi ultro adversatus . . . non sine ratione credendum est eum sequi passiones amici sui.—Descartes, Epist. Amstelodami, 1683. {42b} Discours sur la Vie et les Ouvrages de Pascal, p. xviii. {43a} Any reader curious as to how far Descartes had advanced in this matter may consult Montucla, Histoire des Mathématiques, vol. vi. p. 205. Montucla, no less than Baillet, writes with a clear bias in Descartes’s favour. {43b} Récit de la grande Expérience de l’Équilibre des Liqueurs. Œuvres, t. iv. p. 301—“Je méditai des lors l’expérience dont je fais voir ici le Récit.” {44} Intererat mea id rescire, ipse enim petii ab illo, jam exacto biennio, ut id faceret, eumque pulchri successus certum reddidi, quod esset omnino conforme meis Principiis, absque quo nunquam de eo cogitasset, eo quod contrariâ tenebatur sententiâ.—Ep. lxix., ibid. {45a} Professor Tait, article “Vacuum,” Chambers’s Encyclopedia.