United States or Russia ? Vote for the TOP Country of the Week !
And this last point is demonstrated even more clearly by the celebrated experiment of Torricelli, in which the tube of glass from which the quicksilver has withdrawn itself, remaining void of air, transmits Light just the same as when air is in it.
One can then in this way conceive of transparency in a solid without any necessity that the ethereal matter which serves for light should pass through it, or that it should find pores in which to insinuate itself. But the truth is that this matter not only passes through solids, but does so even with great facility; of which the experiment of Torricelli, above cited, is already a proof.
Torricelli and Benedetti were of the third generation after Leonardo, and Galileo, the first to make a substantial advance upon his theory, was born more than a century after him. Only two or three men appeared in a generation who, working alone, could make real progress in discovery, and even these could do little in leavening the minds of their fellowmen with the new ideas.
When you say that the blood circulates, that the air is heavy, that the sun's rays are pencils of seven refrangible rays, you are not either of the sect of Harvey, or the sect of Torricelli, or the sect of Newton; you agree merely with the truth demonstrated by them, and the entire universe will ever be of your opinion.
And sometimes they would rise or fall as the air was hot or cold." It was in the course of these experiments that the observations made by Boyle led to the invention of his "statical barometer," the mercurial barometer having been invented, as we have seen, by Torricelli, in 1643.
When not engrossed with the duties of public office, he devoted his time to the study of the sciences, particularly pneumatics and electricity, both then in their infancy. The discoveries of Galileo, Pascal, and Torricelli incited him to solve the problem of the creation of a vacuum a desideratum since before the days of Aristotle.
He was at pains to explain the distinction betwixt his own experiments and those which had been made in Italy; and not content with this, he added in express words, in an “avis au lecteur,” that he “was not the inventor of the original experiment, but that it had been made in Italy four years before.” So little, indeed, did Pascal borrow directly from Torricelli, or seek to appropriate the fruits of his researches, that he was as yet ignorant of the explanation which the Italian had suggested of the phenomenon so fully established.
A monument to Pascal, erected by the citizens, occupies the centre of the square in Clermont. It will be remembered that Pascal verified the conclusions arrived at by Torricelli regarding the pressure of the atmosphere, by carrying a Torricellian tube to the summit of the Puy de Dôme, and recording how the mercury continually fell during the ascent, and rose as he descended.
He was himself, it need hardly be said, dissatisfied with such a reply, and accordingly he invited his pupil, Torricelli, to investigate the subject. The latter very soon found that the weight of the water was concerned in the result.
If the mercury descended to a certain mark on the scale on a mountain-top whose height was known, why was not this a means of measuring the heights of all other elevations? And so the beginning was made which, with certain modifications and corrections in details, is now the basis of barometrical measurements of heights. In hydraulics, also, Torricelli seems to have taken one of the first steps.
Word Of The Day