TORRICELLI (Evangeliste)

, an illustrious mathematician and philosopher of Italy, was born at Faenza in 1608, and trained up in Greek and Latin literature by an uncle, who was a monk. Natural inclination led him to cultivate mathematical knowledge, which he pursued some time without a master; but at about 20 years of age, he went to Rome, where he | continued the pursuit of it under father Benedict Castelli. Castelli had been a scholar of the great Galileo, and had been appointed by the pope professor of mathematics at Rome. Torricelli made such progress under this master, that having read Galileo's Dialogues, he composed a Treatise concerning motion upon his principles. Castelli, surprised at the performance, carried it and read it to Galileo, who heard it with great pleasure, and conceived a high esteem and friendship for the author. Upon this, Castelli proposed to Galileo, that Torricelli should come and live with him; recommending him as the most proper person he could have, since he was the most capable of comprehending those sublime speculations, which his own great age, infirmities, and want of sight, prevented him from giving to the world. Galileo accepted the proposal, and Torricelli the employment, as things of all others the most advantageous to both. Galileo was at Florence, at which place Torricelli arrived in 1641, and began to take down what Galileo dictated, to regulate his papers, and to act in every respect according to his directions. But he did not long enjoy the advantages of this situation, as Galileo died at the end of only three months.

Torricelli was then about returning to Rome; but the Grand Duke engaged him to continue at Florence, making him his own mathematician for the present, and promising him the professor's chair as soon as it should be vacant.

Here he applied himself intensely to the study of mathematics, physics, and astronomy, making many improvements and some discoveries. Among others, he greatly improved the art of making microscopes and telescopes; and it is generally acknowledged that he first found out the method of ascertaining the weight of the atmosphere by a proportionate column of quicksilver, the barometer being called from him the Torricellian tube, and Torricellian experiment. In short, great things were expected from him, and great things would probably have been farther performed by him, if he had lived: but he died, after a few days illness, in 1647, when he was but just entered the 40th year of his age.

Torricelli published at Florence in 1644, a volume of ingenious pieces, intitled, Opera Geometrica, in 4to. There was also published at the same place, in 1715, Lezzioni Accademiche, consisting of 96 pages in 4to. These are discourses that had been pronounced by him upon different occasions. The first of them was to the academy of La Crusca, by way of thanks for admitting him into their body. The rest are upon subjects of mathematics and physics. Prefixed to the whole is a long life of Torricelli by Thomas Buonaventuri, a Florentine gentleman.