Cosmos; A Sketch of a Physical Description of the Universe Volume 3 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1892 edition. Excerpt: ... II. HATTIBAL AND TELESCOPIC VISION.--SCINTILLATION OF THE STABS. TELOCITY OF LIGHT. BESULTS OF PHO TOMETBY. The increased power of vision yielded nearly two hundred and fifty years ago by the invention of the telescope, has afforded to the eye, as the organ of sensuous cosmical contemplation, the noblest of all aids towards a knowledge of the contents of space, and the investigation of the configuration, physical character, and masses of the planets and their satellites. The first telescope was constructed in 1608, seven years after the death of the great observer, Tycho Brahe. Its earliest fruits were the successive discovery of the satellites of Jupiter, the Sun's spots, the crescent-shape of Venus, the ring of Saturn as a triple planetary formation, (planeta tergemiuus, ) telescopic stellar swarms, and the nebulae in Andromeda.' In 1634, the French astronomer, Morin, eminent for his observations on longitude, first conceived the idea of mounting a telescope on the index bar of an instrument of measurement, and seeking to discover Arcturus ty day.2 The perfection in 1 See Cosmos, vol. ii. pp. 699-71, with notes. Delambre, Histoire de I'Astronomie moderne, tom. ii. pp. 255, 269, 272. Morin, in his work. Scientia Longitudinum, which appeared in 1634, writes as follows: --Applicatio tubi optici ad alhidadam pro stellis Jixis prompte et accuiale mensurandis a me excogitata est. Picard had not, up to the year 1667, employed any telescope on the mural circle; and Hevelius, when Halley visited him at Dantzic in 1679, and admired the precision of his measurement of altitudes, was observing through improved slits or openings. (Baily's Catal. of Stars, p. 38.) the graduation of the arc would have failed entirely, or to a considerable...