Glance: in english!

  • 23.08.14


    Invention of the telescope and early discoveries with it

    It is singular that the epoch of the most extensive discoveries upon the surface of our planet was immediately succeeded by man’s first taking possession of a considerable part of the celestial spaces by the telescope. The powers of this instrument have not yet reached their limit. The feeble commencement, however hardly magnifying as much as thirty-two times in linear dimension, enabled astronomers to penetrate into cosmical depths, before unknown. The accidental discovery of the space-penetrating power of the telescope was first made in Holland, probably as early as the close of 1608. According to the latest documentary investigations, this great invention may be claimed by Hans Lippershey, a native of Wesel and a spectacle-maker at Middelburg, who, on the 2nd of October, 1608, offered to the States-General certain instruments “with which one can see to a distance.” Two other persons, Adrienz and Jansen, made a similar offer, nearly at the same time.

    When the news of the Dutch invention reached Venice, Galileo was accidentally present; he at once divined what were the essential conditions of the construction, and immediately completed a telescope at Padua for his own use. He directed it first to the mountains in the moon; then examined with small magnifying powers the group of the Pleiades, the cluster of stars in Cancer, the Milky Way, and the group of stars in the head of Orion. Then followed in quick succession the great discovery of the four satellites of Jupiter, the two “handles” of Saturn, or his surrounding ring imperfectly seen, so that its true character was not at once recognised; the solar spots, and the crescent form of Venus. The occultations of the satellites, or their entrance into the shadow of Jupiter, led to the knowledge of the velocity of light; and led Galileo to perceive their importance in the determination of the longitude of places on land.

    Galileo carried his first telescope to Venice, where his time for more than a month was employed in showing and explaining its nature to the different inhabitants. A ludicrous instance is related of the insatiable telescope mania which had seized on the people. Galileo went one day to the tower of St. Mark, in order to make observations on its summit, but the people espied him, and compelled him to hand a telescope which he had made for himself, from one to another, until all had gratified their curiosity by having a peep; and, after he had been detained several hours, he was not a little glad to regain his telescope, and return home. But this was not all: he heard them inquiring at what inn he lodged; and foreseeing the inconvenience of the celebrity which was beginning to attach to him, he left Venice early the next morning, to pursue his observations with greater privacy.

    Melancholy is it to relate that these brilliant disclosures brought temporary disgrace and positive suffering upon their author. Galileo, at the age of seventy-seven, after having devoted his life to useful and valuable labours, was forced to abjure his philosophical opinions, and to declare, on his knees, that he believed his doctrines concerning the motion of the earth round the sun, the existence of solar spots, &c., to be false and pernicious. The moral firmness of the old man was not sufficient to make him brave the terrors of the Inquisition, and we must therefore look with a lenient eye at this abjuration of doctrines which at the very moment he firmly believed to be true: but what shall we say of those men, who, under the plea of religion, could subject so noble a mind to such humiliating degradation!



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