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 17
... less distances . The whole circular path of a star is above the horizon , and is visible , only when the distance of the star from the fixed point , that is , the radius of the apparent motion , is less than the altitude ( 13 ) of the ...
... less distances . The whole circular path of a star is above the horizon , and is visible , only when the distance of the star from the fixed point , that is , the radius of the apparent motion , is less than the altitude ( 13 ) of the ...
Página 31
... less than the co - latitude of the place , and the declination of the sun is 23 south . Fig . 15 . 1500 73 % 26 % 0 22 DEC . 20 MCH . 22 SEP . 20 JUN . 53. Example . - When the observer is in lat . 40 ° , the co - latitude of the place ...
... less than the co - latitude of the place , and the declination of the sun is 23 south . Fig . 15 . 1500 73 % 26 % 0 22 DEC . 20 MCH . 22 SEP . 20 JUN . 53. Example . - When the observer is in lat . 40 ° , the co - latitude of the place ...
Página 56
... less , south . But the meridian altitude of the equi- noctial is equal to the co - latitude of the place of obser- vation ( App . I ) ; we find , therefore , the declination of a star to be the difference between its meridian altitude ...
... less , south . But the meridian altitude of the equi- noctial is equal to the co - latitude of the place of obser- vation ( App . I ) ; we find , therefore , the declination of a star to be the difference between its meridian altitude ...
Página 59
... less , but in either case , such an error may cause disaster . 113. Longitude by eclipses of Jupiter's satellites . — The difference of longitude between two places may be found by observing at one place any event in the sky which has ...
... less , but in either case , such an error may cause disaster . 113. Longitude by eclipses of Jupiter's satellites . — The difference of longitude between two places may be found by observing at one place any event in the sky which has ...
Página 61
... less than 24 hours . If it has moved directly north or south , the time of transit will not vary , but the mural circle will detect a change of altitude . 117. Fixed stars are those which keep their places in the sky . A few stars ...
... less than 24 hours . If it has moved directly north or south , the time of transit will not vary , but the mural circle will detect a change of altitude . 117. Fixed stars are those which keep their places in the sky . A few stars ...
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.