Laboratory AstronomyGinn & Company, 1901 - 90 стор. |
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Загальні терміни та фрази
12 hours 24 hours absolute right ascension accuracy accurate adjustment Aldebaran altazimuth angle ascension and declination astronomy autumnal equinox axis bubble celestial sphere Ceti Chapter circle reading convenient cross cross-staff DECL declination circle degree determined difference of right diurnal circle diurnal motion east and west ecliptic equal equator equatorial instrument error exactly fixed follows the vernal gives globe graduated hemisphere horizontal circle hour-angle hour-circle inches interval latitude latter leveling screw means measured meridian circle meridian mark meridian passage meridian reading method minutes minutes of arc moon motion nearly as possible orbit pencil point perpendicular place of observation plane plotting pole position protractor read the circles September 22 Serpentis shown in Fig sidereal clock sphere ß Pegasi star follows star's sun observation sun's declination sun's path telescope points tion true value tube Venus vernal equinox vertical circle watch y Pegasi zenith distance
Популярні уривки
Сторінка 16 - Equinoctial, is the great circle in which the plane of the earth's equator produced intersects the surface of the celestial sphere.
Сторінка 47 - ... they should have been previously cut in the house, from the pattern given by one of the cards that had been mounted and cut in the instrument. In mounting the instrument in place, the points to attend to are, (1) that it shall be level as regards east and west, (2) that the axis of the ring shall be inclined to the horizon at an angle equal to the latitude of the place...
Сторінка 16 - ... about 5 Ibs. in weight, as a brick, stone, iron ring, or coupling. It will serve the same purpose, with as accurate results, as the most highly polished or carefully manufactured plumb-bob. The plumb-line should be about 25 feet in length, depending upon the latitude of the place, since the altitude of the pole above the horizon at any place is equal to the latitude of that place. Illuminate the plumb-line just below its support by means of a bull's-eye lantern, lamp, or candle, care being taken...
Сторінка 1 - THE SUN'S HEAT. WE say that the sun rises in the east and sets in the west; but we know it does not rise or set.
Сторінка 74 - The appearance will be exactly the same as before only if the axis of the telescope is perpendicular to the axis of rotation ; if...
Сторінка 76 - CD is inclined 2', etc., the inclination in minutes of arc being one-half the difference of the readings of the ends of the bubble, or —-— if A and B represent the readings of the ends of the bubble in each case.
Сторінка 56 - Pegasi as a zero star, the point upon the equator at which the sun crosses it from south to north about March 21 of each year.
Сторінка 71 - The sun's diameter should occasionally be measured to determine the points at which it is nearest to and farthest from the earth.
Сторінка 74 - A pointer attached to the support marks the zero of the vertical circle when the telescope points to the zenith, and...