History of Astronomy |
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Page 35
... bright- ness . The telescope not having been invented , he could not use a telescopic - sight as we now do in gunnery . This not only removes the difficulty of focussing , but makes the minimum visible angle smaller . Helmholtz has ...
... bright- ness . The telescope not having been invented , he could not use a telescopic - sight as we now do in gunnery . This not only removes the difficulty of focussing , but makes the minimum visible angle smaller . Helmholtz has ...
Page 90
... bright lines . If sodium or common salt be thrown on the colourless flame of a spirit lamp , it gives it a yellow colour , and its spectrum is a bright yellow line agreeing in position with line D of the solar spectrum . R. S. Phil ...
... bright lines . If sodium or common salt be thrown on the colourless flame of a spirit lamp , it gives it a yellow colour , and its spectrum is a bright yellow line agreeing in position with line D of the solar spectrum . R. S. Phil ...
Page 95
... bright areas , which are seen all over the sun's surface , but specially in. As Photographed at the Royal Observatory , Greenwich , showing sun - spots with umbræ , penumbræ , and faculæ . SOLAR ECLIPSE , 1882 . THE PHYSICAL PERIOD 95.
... bright areas , which are seen all over the sun's surface , but specially in. As Photographed at the Royal Observatory , Greenwich , showing sun - spots with umbræ , penumbræ , and faculæ . SOLAR ECLIPSE , 1882 . THE PHYSICAL PERIOD 95.
Page 101
... bright lines of hydrogen or of calcium , by means of the " Spectroheliograph . " The spectro- scope is placed with its slit in the focus of an equatoreal telescope , pointed to the sun , so that the circular image " The Sun as ...
... bright lines of hydrogen or of calcium , by means of the " Spectroheliograph . " The spectro- scope is placed with its slit in the focus of an equatoreal telescope , pointed to the sun , so that the circular image " The Sun as ...
Page 105
... bright line spectrum , indicating the presence of hydrogen and other gases . So bright was it that Jansen exclaimed : " Je verrai ces lignes - là en dehors des éclipses . " And the next day he observed the lines at the edge of the ...
... bright line spectrum , indicating the presence of hydrogen and other gases . So bright was it that Jansen exclaimed : " Je verrai ces lignes - là en dehors des éclipses . " And the next day he observed the lines at the edge of the ...
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Common terms and phrases
accurate observations Airy astro Astronomer Royal Astronomia Nova astronomical units attraction axis bright calculations Cape Cassini catalogue centre century comet compute Copernicus diameter discovered discovery earth eclipse epicycles equatoreal error excentric explain fact fixed stars Galileo Greenwich Halley heavenly bodies heavens heliometer Hipparchus Huggins hydrogen hypothesis instruments Johann Kepler John Herschel Jupiter Jupiter's Kepler Laplace Lick Observatory light line of apses line of sight lunar Mars mathematical mean distance mean motion measured Mercury meteor method miles a second moon moon's nebulæ Newton Observatory orbit parallax perihelion period photographic physical planet planetary pole position predicted proper motion proved Ptolemy R. S. Phil records refractor retrograde retrograde motion revolution revolve round ring rotation round the sun satellites seems showed Sirius solar system spectra spectroscope spectrum spots stellar sun-spots sun's surface supposed tables telescope theory tion Trans Tycho Brahe Uranus velocity Venus Verrier zenith