Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous (14760521186)

Identifier: triumphswonderso01boyd (find matches)
Title: Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress ..
Year: 1899 (1890s)
Authors: Boyd, James Penny, 1836-1910
Subjects: Progress Inventions
Publisher: Philadelphia, Pa., A. J. Holman & Co
Contributing Library: The Library of Congress
Digitizing Sponsor: Sloan Foundation



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anding the fact that our largest telescopes give onlynegative testimony. In a solar eclipse in February, 1736, that was annular in shape, just beforethe sun was completely hidden, the narrow horn of light seemed to breakinto a series of dots, or luminous points, which, when noted again a centurylater and described by Francis Baily, received the name of Baily Beads.It was attempted to explain this as caused by the moons mountains cuttingoff the last rays of sunlight, or else as produced by irradiation. But withthe advent of stronger telescopic power the phenomenon has come to an end. David Bittenhouse, of Norristown, whom Thomas Jefferson considered sec- ASTRONOMY DURING THE CENTURY 103 oncl to no astronomer living, built an orrery worth a thousand dollars, toillustrate mechanically the motions of all the planets, and though the instru-ment is still treasured in the University of Pennsylvania, and its duplicateat Princeton, among the relics of a past age, it is assigned to the category
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THREE-INCH TRANSIT. j;\ WARNER A: SWASEY. of toys. Mural circles, much depended upon to measure the declination ofheavenly bodies, have fallen into disuse, supplanted by improved transitinstruments. XVI. PROBLEMS FOB FUTURE STUDY. Many problems are in store for the future. The field for research stillopens wide. How the solar activity is to be maintained was answered byNewton in the suggestion that comets falling into it kept up its supply ofmatter and energy. Waterston, in 1853, propounded the thought thai mete-oric matter may be the aliment of the sun. Now the prevalent theory is 104 TRIUMPHS AND WONDERS OF THE XIXth CENTURY that a contraction of the suns volume, constantly in progress, but so slightas to be invisible to the most powerful telescope, is competent to furnish aheat supply equal to all that can have been emitted during historic periods. Professor Newcomb answers the question, How long will the sun en-dure ? by saying, The physical conclusion to which we are led by a stu