Étienne Pascal was rewarded for all his self-devotion by the genius of his son. His daughters also profited by his care, and became distinguished at once by their mental accomplishments and their personal beauty. A disaster that occurred, which at first disturbed the happiness of the family, tended in the end to establish it, and to bring into greater notice the talents and virtues of the individuals of which it was composed.
1638.
Ætat.
15.
The finances of the government being at a low ebb, through mismanagement and long wars, the minister, cardinal de Richelieu, sought to improve them by diminishing the rate of interest towards the public creditor. Of course this act excited considerable discontent among holders of public stock; riots ensued, and some men, in consequence, were imprisoned in the Bastille. Among these was a friend of Étienne Pascal, who openly and warmly defended him, while he cast considerable blame on several government functionaries, and in particular the chancellor Séguier. This imprudence endangered his own liberty; he heard that he was threatened with arrest, and to avoid it left Paris, and for several months hid himself in Auvergne. He had many friends however among noble patrons of learning, and the duchess d'Aiguillon, in particular, interested herself in his favour. Richelieu, as is well known, was very fond of theatrical representations, and a tragi-comedy by Scuderi, was got up for his amusement. Jaqueline Pascal, then only fourteen years old, was selected to fill one of the parts: she at first refused, saying that the cardinal gave them too little pleasure for her to try to contribute to his; but the duchess saw hopes for the father's recall in the daughter's exertions, and persuaded Jaqueline to undertake the part. She acted charmingly, and at the end of the piece approached the cardinal, and recited some verses written for the occasion, asserting the innocence of her father, and entreating the cessation of his exile. The cardinal delighted, took her in his arms, and kissing her again and again, said, "Yes, my child, I grant your request; write to your father, that he may safely return." 1639.
Ætat.
16. The duchess followed up the impression by an eulogium on Pascal, and by introducing Blaise; "He is but sixteen," she said, "but he is already a great mathematician." Jaqueline saw that the cardinal was favourably inclined; and with ready tact, added, that she had another request to prefer. "Ask what you will, my child," said the minister, "I can refuse you nothing." She begged that her father, on his return, might be permitted personally to thank the cardinal. This also was granted; and the family reaped the benefit. The cardinal received the exile graciously; and, two years after, named him intendant of Normandy at Rouen. Étienne removed with his family, in consequence, to that city. He filled the situation for seven years, enjoying the highest reputation for integrity and ability. About the same time, his daughter, Gilberte, formed an advantageous marriage with M. Périer, who had distinguished himself in a commission entrusted to him by the government in Normandy, and who afterwards bought the situation of counsellor to the court of aids of Clermont-Ferrand.
1641.
Ætat.
18.
Blaise, meanwhile, was absorbed in scientific pursuits. To the acquisition of Latin and Greek was added the study of logic and physics; every moment of his time was occupied—and even during meals the work of study went on. Charmed with the progress his son made, and his apparent facility in learning, the father was blind to the ill-effects that such constant application had on his health: at the age of eighteen, Pascal began to droop; the indisposition he suffered was slight, and he did not permit it to interfere with his studies; but neglected, and indeed increased, it at last entirely disorganised his fragile being. From that hour he never passed a single day free from pain. Repose, taken at intervals, mitigated his sufferings; but when better he eagerly returned to study—and with study illness recurred.
1642.
Ætat.
19.
His application was of the most arduous and intense description. At the age of nineteen he invented his arithmetical machine, considered one of the most wonderful discoveries yet put into practice. A machine capable of automatic combinations of numbers has always been a desideratum; and Pascal's was sufficiently well arranged to produce exact results—but it was very complex, expensive, and easily put out of order, and therefore of no general utility, though hailed by mathematicians as a most ingenious and successful invention. It cost him intense application, both for the mental combinations required, and the mechanical part of the execution:—his earnest and persevering study, and the great efforts of attention to which he put his brain, increased his ill health so much that he was obliged for a time to suspend his labours.
Soon after this, a question, involving very important consequences in physics, agitated the scientific world, and the position of the two Pascals was such, that their attention could not fail to be drawn to the consideration of it. The mechanical properties of the atmosphere had previously been inquired into by Galileo, who recognised in it the quality of weight. This philosopher, however, notwithstanding the wonderful sagacity which his numerous physical discoveries evince, failed to perceive that the weight of the atmosphere, combined with its fluidity and elasticity, opposed a definite force to any agent by which the removal of the atmosphere from any space was attempted. This resistance to the production of a vacuum had long been recognised, and was in fact expressed, but not accounted for, by the phrase, "nature's abhorrence of a vacuum." Whatever meaning he may have attached to it, Galileo retained this phrase, but limited its application, in order to embrace the phenomenon, then well known, that suction-pumps would not raise water more than about thirty-five feet high; and although "nature's abhorrence of a vacuum" raises the water thirty-five feet, to fill the space deserted by the air, which had been drawn out by the piston, yet above that height a vacuum still remained; which fact Galileo expressed by saying, that "thirty-five feet was the limit of nature's abhorrence of a vacuum."
That Galileo should have missed a discovery as important as it was obvious, is the more remarkable from the circumstance of its having been actually suggested to him by one of his own pupils. A letter from Baliani to Galileo is extant, dated in 1630, in which the writer says that Galileo, in one of his letters to him, having taught him that air has sensible weight, and shown him how that weight might be measured, he argued from thence that the force necessary to produce a vacuum, was nothing more than the force necessary to remove the weight of the mass of atmosphere which presses round every object, just as water would press on any thing at the bottom of the sea.[54]
Torricelli, the pupil of Galileo, next took up the problem. He argued, that if the weight of the atmosphere were the direct agent by which the column of water is sustained in a pump, the same agent must needs exert the same amount of force in sustaining a column of any other liquid; and, therefore, that if a heavier liquid were used, the column sustained would be less in height exactly in the same proportion as the weight of the liquid forming the column was greater. Mercury, the heaviest known liquid, appeared the fittest for this purpose. The experiment was eminently successful. The weight, bulk for bulk, of mercury was fourteen times greater than that of water; and it was found that, instead of a column of thirty-five feet being supported, the column was only thirty inches, the latter being exactly the fourteenth part of thirty-five feet.