AMONTONS, WILLIAM, a celebrated experimental philosopher, was born on the ;1st of August, 1663. His lather was a lawyer in Normandy, who, from motives that have not been recorded, removed with Iris family to Paris. In early life, while Amontons was yet at school, he was deprived of his hearing; a loss whidr, though it excluded him from the society and converse of hi, friends, engaged him to give his undivided attention tt, the study of geometry and mechanics. Like the ancient philosopher who pulled out his eyes, that he might not he distracted by the sight of external objects, A111011 tons is said to have refused every remedy for a disease which compelled him to devote to philosophy those por tions of his time, which might otherwise have been wasted in a vain and fruitless intercourse with the world. But whatever praise may be due to such stoical forti tude, we cannot think highly of the man who willingly surrenders the privilege of contemplating the ever-va rying riches of creation, or who would prefer solitary speculation to that noble communion of souls, which is the characteristic of rational beings. It is true philo sophy to bear with equanimity the evils of life ; but it is empiricism to create or to cherish sufferings.
The attention of Amontons was first directed to the perpetual motion ; a subject which, like the philoso pher's stone, has long continued to excite the ambition and perplex the understanding, of the credulous and the ignorant. He was, however, soon convinced of the dif ficulty of his project, though he still expected, that, by the aid of mathematical principles, he might carry it into execution. Geometry, therefore, became his fa vourite study ; and he pursued it with unabating ardour, in spite of the opposition and remonstrances of his friends. Along with this branch of abstract science, he studied drawing, architecture, and land-surveying; and from the skill which he acquired in these practi cal departments, he was employed in several public works.
Amontons likewise employed his ingenuity in the construction of instruments for measuring the variations in the state of our atmosphere. He proposed an air thermometer, grounded on more accurate and philoso phical principles than any hitherto contrived. In the course of his researches, he found that the boiling point of water is variable, and depends on the atmospheric pressure ; an important discovery which was also made about the same time by Dr Halley in England. Amon tons suggested several improvements on the barometer; and, at the age of twenty-four, he presented to the Royal Academy of Sciences a new hygrometer, which re ceived the approbation of that learned body. These improvements, however, are now eclipsed by the deli cate instruments which have been more recently brought to forward the progress of physical science.
In 1669, when the academy of sciences was new-mo delled, Amontons was elected a member. He invented a telegraph very like that now in use. His new theory of friction, which he read at one of their meetings, was a valuable communication, upon a subject which had scarcely excited the attention of philosophers; and his researches on that subject were regarded as the most ingenious and correct, till they were superseded by the more accurate and extensive experiments of Coulomb.
Though Amontons had always enjoyed the most per feet health, he was suddenly attacked with an inflanm41 tion of his bowels, which terminated his existence on the Ilth of October, 1705, and in the 42d year of his age. In private life, he was distinguished by an inte grity of mind, and a frankness, candour, and simplicity of manner, which naturally sprung from his seclusion from the world. Ills genius for invention and for ex perimental philosophy, appears in the numerous papers with which he enriched the Memoirs ol the Academy from 1696 to 1705. Sec HYGROMETER and Timosto METER. (p)