History of Astronomy |
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Page 9
... circle into 365 degrees . To learn the length of the year needed only patient observation — a characteristic of the Chinese ; but many younger nations got into a terrible mess with their calendar from ignorance of the year's length ...
... circle into 365 degrees . To learn the length of the year needed only patient observation — a characteristic of the Chinese ; but many younger nations got into a terrible mess with their calendar from ignorance of the year's length ...
Page 18
... circle having this centre was called the equant , and he supposed that a radius drawn to the sun from the excentric passes over equal arcs on the equant in equal times . He then computed tables for predicting the place of the sun . He ...
... circle having this centre was called the equant , and he supposed that a radius drawn to the sun from the excentric passes over equal arcs on the equant in equal times . He then computed tables for predicting the place of the sun . He ...
Page 22
... circle ( the epicycle ) , whose centre revolves round the earth on the primary circle ( the deferent ) , at a uniform rate round the excentric . Ptolemy supposed the centres of the epicycles of Mercury and Venus to be on a bar passing ...
... circle ( the epicycle ) , whose centre revolves round the earth on the primary circle ( the deferent ) , at a uniform rate round the excentric . Ptolemy supposed the centres of the epicycles of Mercury and Venus to be on a bar passing ...
Page 30
... , the impression is made that the jointed bars there spoken of for describing the circles . were supposed to be real . This is no more the case than that the spheres of Eudoxus and Callippus were supposed 30 THE GEOMETRICAL PERIOD.
... , the impression is made that the jointed bars there spoken of for describing the circles . were supposed to be real . This is no more the case than that the spheres of Eudoxus and Callippus were supposed 30 THE GEOMETRICAL PERIOD.
Page 56
... circle , ellipse , parabola , or hyperbola ; and he found that those comets of which he had observations move in parabolæ round the Sun , and are thus subject to the universal law . Newton realised that , while planets and satellites ...
... circle , ellipse , parabola , or hyperbola ; and he found that those comets of which he had observations move in parabolæ round the Sun , and are thus subject to the universal law . Newton realised that , while planets and satellites ...
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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