A System of Astronomy: On the Principles of CopernicusJ.B. Moore, 1827 - 252 pages |
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Page ix
... proportion to the centripetal . CHAPTER IV . Equation of time . Time measured by the sun differs from that of a good clock or watch ; the sun and clock are together four times in a year ; the inequality in the meas- urement of time ...
... proportion to the centripetal . CHAPTER IV . Equation of time . Time measured by the sun differs from that of a good clock or watch ; the sun and clock are together four times in a year ; the inequality in the meas- urement of time ...
Page 26
... proportion , upwards from the surface of the earth . If the decrease be not always thus proportioned , yet it is certain , that the air becomes very rare in high regions , as fully tested by experiment on the tops of lofty mountains ...
... proportion , upwards from the surface of the earth . If the decrease be not always thus proportioned , yet it is certain , that the air becomes very rare in high regions , as fully tested by experiment on the tops of lofty mountains ...
Page 41
... proportion as the co - sines of the latitudes . Thus , to find the velocity , per hour , in any lati- tude , say , as radius is to the co - sine of such latitude ; so are 1042 miles , to the distance passed in one hour by any place in ...
... proportion as the co - sines of the latitudes . Thus , to find the velocity , per hour , in any lati- tude , say , as radius is to the co - sine of such latitude ; so are 1042 miles , to the distance passed in one hour by any place in ...
Page 43
... proportion , than that of the earth , illuminated by the sun . While in this position , let the globe be turned gently round , from west to east . Every part of the surface will pass through a proportion of light and darkness , nearly ...
... proportion , than that of the earth , illuminated by the sun . While in this position , let the globe be turned gently round , from west to east . Every part of the surface will pass through a proportion of light and darkness , nearly ...
Page 44
... . 5 of Plate V. In winter , the scene is reversed , the southern hemisphere taking the greater proportion of light , the northern of dark- ness . 1 The difference in the modes of projection , observable 44 THE SOLAR SYSTEM .
... . 5 of Plate V. In winter , the scene is reversed , the southern hemisphere taking the greater proportion of light , the northern of dark- ness . 1 The difference in the modes of projection , observable 44 THE SOLAR SYSTEM .
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Common terms and phrases
altitude angle aphelion appear Aries ascending node astronomers atmosphere axis bissextile calculated celestial centre comets conjunction constellation dark shadow declination degree diameter disk diurnal motion diurnal rotation divided dominical letter earth earth's shadow eclipse Epact equal equator equinox fast of clock full moon heavenly body heavens Herschel horary motion horizon hour inferior conjunction Jupiter latitude light longitude and anomaly luminous lunar lunation March Mars mean anomalies mean distance Mercury meridian miles minutes month moon's orbit obliquity observed opposite parallax parallel passing penumbra perihelion planet polar circles pole Proportional Logarithms radius reckoned refraction Retrograde motion revolution right ascension rising round the sun satellites Saturn seen semi-diameter side sidereal slow of clock solar solstice subtract Sun fast Sun slow sun's anomaly sun's mean sun's place surface tides tion transit tropic true Turn the globe Venus visible zenith
Popular passages
Page 200 - Rectify the globe to the latitude of the place; bring the sun's place in the ecliptic to the meridian, and set the index to XII.
Page ii - BBOWN, of the said district, hath deposited in this office the title of a book, the right whereof he claims as author, in the words following, to wit : " Sertorius : or, the Roman Patriot.
Page 177 - Observer' at a salary of 100£ per annum, his duty being 'forthwith to apply himself with the most exact care and diligence to the rectifying the tables of the motions of the heavens and the places of the fixed stars, so as to find out the so much desired longitude of places for the perfecting the art of navigation.
Page iv - ... constitution of the universe by the means of these buildings and of observers stationed in them, shall we doubt of their usefulness to every nation? And while scarcely a year passes over our heads without bringing some new astronomical discovery to light, which we must fain receive at...
Page 179 - ... that, situated as we are in this Western hemisphere, more than three thousand miles from any fixed or known meridian, it would be proper, in a national point of view, to establish a first meridian for ourselves ; and that measures should be taken for the eventual establishment of such a meridian in the United States. In examining the maps and charts of the United States, and the particular States, or their...
Page 160 - The atmosphere is known to abound with electric matter, and the appearance of the electric matter in vacuo is exactly like the appearance of the aurora borealis, which, from its great altitude, may be considered to be in as perfect a vacuum as we can make. The electric matter in vacuo suffers the rays of light to pass through, without being affected by them. The tail of a comet does not expand itself sideways, nor does the electric matter. Hence, he supposes the tails of comets, the aurora borealis,...
Page 162 - ... aperture; and, at another time, in 41 minutes, he saw 258,000 stars pass through the field of his telescope. Every improvement in his...
Page 179 - Junonia, one of these islands, supposed to be the present island of Teneriffe. " The Arabians, it is said, fixed their firs,t meridian at the most westerly part of the continent of Africa. In the fifteenth and sixteenth centuries, when Europe was emerging from the dark ages, and a...
Page 66 - There is not, perhaps," said this great and sound astronomer, " another object in the heavens that presents us with such a variety of extraordinary phenomena as the planet Saturn ; a magnificent globe encompassed by a stupendous double ring ; attended by seven satellites; ornamented with equatorial belts; compressed at the poles ; turning on its axis ; mutually eclipsing its rings and satellites, and eclipsed by them ; the most distant of the rings also turning on its axis, and the same taking place...
Page 138 - A month in law is a lunar month, or twenty-eight days, unless otherwise expressed ; not only because it is always one uniform period, but because it falls naturally into a quarterly division by weeks. Therefore a lease for