The Elements of Astronomy: For Colleges, Schools, and Private Students : Written for the Mathematical Course of Joseph RayWilson, Hinkle & Company, 1869 - 336 páginas |
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Página 43
... ring , A , which is adjusted in the tube of the telescope by the screws , a , a . In the day , they are seen as two fine dark lines across the object viewed . In the night , they must be lighted by a lamp placed where its rays may fall ...
... ring , A , which is adjusted in the tube of the telescope by the screws , a , a . In the day , they are seen as two fine dark lines across the object viewed . In the night , they must be lighted by a lamp placed where its rays may fall ...
Página 59
... carries an index over the graduated scale A. At F is a mirror called the horizon glass , silvered only on its lower half . The observer , holding the instrument by the handle behind the frame , places his eye at the ring K LONGITUDE . 59.
... carries an index over the graduated scale A. At F is a mirror called the horizon glass , silvered only on its lower half . The observer , holding the instrument by the handle behind the frame , places his eye at the ring K LONGITUDE . 59.
Página 60
... ring K , and looks through the open part of the mirror F at some object , as a star . Fig . 43 . protect the eye when the sun is out of the way at other times . He then moves the index along the scale , until the image of another object ...
... ring K , and looks through the open part of the mirror F at some object , as a star . Fig . 43 . protect the eye when the sun is out of the way at other times . He then moves the index along the scale , until the image of another object ...
Página 149
... ring , which afterward consolidated into a planet , and perhaps imitated this action in the evolution of satellites . 298. Ideas of the sun's greatness . - In the last chapter , we found the distance from the earth to the sun to be 95 ...
... ring , which afterward consolidated into a planet , and perhaps imitated this action in the evolution of satellites . 298. Ideas of the sun's greatness . - In the last chapter , we found the distance from the earth to the sun to be 95 ...
Página 179
... rings , walled basins , or craters . These appear to be of volcanic origin , if not the actual craters of volcanoes . Their diameters are very large , 50 , 100 , and even 133 miles . The walls are steep and ragged , the interior slope ...
... rings , walled basins , or craters . These appear to be of volcanic origin , if not the actual craters of volcanoes . Their diameters are very large , 50 , 100 , and even 133 miles . The walls are steep and ragged , the interior slope ...
Términos y frases comunes
2d mag Alpha Centauri altitude angle appears Arcturus astronomical attraction axis body bright stars brightest called Capricornus cause celestial clock comet conjunction constellation culmination curve daily motion dark declination density diameter distance earth earth's orbit east eccentricity ecliptic equal equator equatorial equinoctial farther fixed stars heat Hence Herschel horizon Jupiter latitude length libration light longitude lunar lunar eclipses Mars mass mean solar measured Mercury meridian meteors millions of miles moon moon's move nearly nebula node observer Ophiuchus opposite parallax particles passes path penumbra perihelion photosphere planet polariscope pole position prime vertical radius rays refraction revolution revolve right ascension ring rotation satellites Saturn seen shadow shows side sidereal sidereal day solar day solar eclipse solar system solstice space spots supposed surface tail telescope tide tion transit triangle Uranus velocity Venus vernal equinox vertical visible zenith
Pasajes populares
Página 143 - The MASS of a body is the quantity of matter which it contains.
Página 237 - Uranus a full-sized cherry, or small plum, upon the circumference of a circle more than a mile and a half in diameter. As to getting correct notions on this subject by drawing circles on paper, or, still worse, from those very childish toys called orreries, it is out of the question.
Página 237 - Mercury will be represented by a grain of mustard seed, on the circumference of a circle 1 64 feet in diameter for its orbit; Venus a pea, on a circle 284 feet in diameter ; the Earth also a pea, on a circle of 430 feet; Mars a rather large pin's head, on a circle of 654 feet...
Página 126 - Hath left to their disputes, perhaps to move His laughter at their quaint opinions wide Hereafter ; when they come to model Heaven And calculate the stars, how they will wield The mighty frame ; how build, unbuild, contrive To save appearances ; how gird the sphere With centric and eccentric scribbled o'er, Cycle and epicycle, orb in orb...
Página 208 - ... she is in the meridian of that place ; and that the sun performs a secondary part in their production may be proved from the circumstance, that the highest tides take place when the sun, the moon, and the earth are in the same straight line, that is, when the force of the sun conspires with that of the moon, and that the lowest tides take place when the lines drawn from the sun and moon to the earth are at right angles to each other, that is, when the force of the sun acts in opposition to that...
Página 298 - Herculis. The velocity of this motion is such that the sun, with the whole cortege of bodies depending on him, advances annually in the direction indicated, through a space equal to 1.623 radii of the terrestrial orbit or one hundred and fifty-four millions of miles.
Página 13 - The vertical circle which passes through the north and south points of the horizon is the same as the celestial meridian, which will be defined hereafter (32).
Página 237 - ... feet; Jupiter a moderate-sized orange, in a circle nearly half a mile across; Saturn a small orange, on a circle of four-fifths of a mile; Uranus a full-sized cherry, or small plum, upon the circumference of a circle more than a mile and a half, and Neptune a good-sized plum on a circle about two miles and a half in diameter.
Página 82 - It is found to be always exactly perpendicular to the plane of the horizon; or, to a plane tangent to the surface of the earth at the point of observation.
Página 279 - ... reduce the intensity to onesixteenth : in short, we thus demonstrate the law that the intensity of light diminishes as the square of the distance increases. This is the celebrated law of Inverse Squares as applied to light.