Outlines of Astronomy |
Other editions - View all
Common terms and phrases
appear astronomers axis ball body bright brighter calculations called celestial objects celestial sphere chromosphere circle clock clouds comet compared consider constellation course determine diameter direction disk distance Earth Earth's atmosphere Earth's centre Earth's orbit Earth's rotation ecliptic equal equator equatorial equatorial stars fact faculæ farther gases heat Hence horizon incandescent Jupiter kind known latitude law of gravitation length lens less light limb liquid longitude look magnitude Mars mass material objects means measure ment meridian meteors miles Moon Moon's move movement nearer nearly north pole northern nutation observations opposite parallax particular passing pencil perihelion perpendicular photosphere plane prism proper motions refraction regard retrograde revolution right ascension ring round the Sun satellites Saturn seen side sidereal sidereal day solid solstice sometimes spectroscope spectrum spots stars straight line suppose surface telescope tion triangle umbra Uranus usually Venus vernal equinox visual angle zenith
Popular passages
Page 80 - The squares of the periodic times of any two planets are to each other, in the same proportion as the cubes of their mean distances from the sun.
Page 199 - As a centre stood the full and intensely black disc of the moon, surrounded by an aureola of soft bright light, through which shot out, as if from the circumference of the moon, straight massive silvery rays, seeming distinct and separate from each other, to a distance of two or three diameters of the lunar disc ; the whole spectacle showing as upon a background of diffused rose-coloured light...
Page 322 - It will be seen that we multiply the denominator of the dividend by the numerator of the divisor for the denominator of the quotient, and the numerator of the dividend by the denominator of the divisor for the numerator of the quotient.
Page 222 - Surfaces of spheres are to each other as the squares of their diameters.
Page 298 - ... directly proportional to the product of the masses and inversely proportional to the square of the distance between them.
Page 392 - The limits of the obliquity of the apparent ecliptic to the equator ^are 24° 35' 58" and 21° 58' 36"; whence it follows that the greatest and least declinations of the sun at the solstices can never differ from each other to any greater extent than 2° 37
Page 81 - It is, that the squares of the periodic times of any two planets are to each other as the cubes of their mean distances from the sun...
Page ii - BROTHERS, In the Office of the Librarian of Congress at Washington. CAMBRIDGE: PRESS OF JOHN WILSON AND SON.
Page 377 - Astronomical Observations and Researches made at Dunsink, the Observatory of Trinity College, Dublin,
Page 296 - Every body continues in its state of rest or of uniform rectilinear motion unless compelled to change its state by forces impressed upon it.