Outlines of AstronomyLongman, Brown, Green, Longmans, 1851 - 661 pages |
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Common terms and phrases
altitude amount angle angular appear apsides ascertained astronomical axis bright calculation celestial centre circle comet curve described diameter difference direction disc distance disturbed body disturbing force diurnal diurnal motion double stars earth ecliptic effect elements ellipse epoch equal equator equinoctial equinox error exact excentricity fixed globe gravity greater heavens heliocentric horizon inclination increase inequality instance instrument interval Jupiter latitude latter length less light longitude lunar magnitude mass mean measure meridian moon moon's motion nearly nebula node normal force nutation object observed orbit parallax parallel perigee perihelion period perturbations planet planetary pole portion position precession precisely proper motions proportion recede recess reckoned refraction remarkable respect result revolution right ascension rotation round satellites Saturn seen sidereal sidereal day sidereal period situation solar sphere spherical stars station sun's suppose syzygies tangential force telescope tion Uranus variation velocity visible whole zenith
Popular passages
Page 224 - Aries, Taurus, Gemini, Cancer,, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces.
Page 268 - that every particle of matter in the universe attracts every other particle, with a force whose direction is that of the line joining the two, and whose magnitude is directly as the product of their masses, and inversely as the square of their distances from each other.
Page 237 - The sun's rays are the ultimate source of almost every motion which takes place on the surface of the earth. By its heat are produced all winds, and those disturbances in the electric equilibrium of the atmosphere which give rise to the phenomena of lightning, and probably also to terrestrial action and the aurora.
Page 59 - Ocean, the first thing which strikes us is, that, the north-east and south-east monsoons, which are found the one on the north and the other on...
Page 268 - Every particle of matter in the universe attracts every other particle with a force directly proportioned to the mass of the attracting particle, and inversely to the square of the distance between them...
Page 537 - In such cases it is equally impossible not to perceive that we are looking through a sheet of stars nearly of a size, and of no great thickness compared with the distance which separates them from us. Were it otherwise we should be driven to suppose the more distant stars uniformly the larger, so as to compensate by their greater intrinsic brightness for their greater distance, a supposition contrary to all probability.
Page 555 - It appears about twelve times in eleven years, — or, more exactly, in a period of 334 days ; remains at its greatest brightness about a fortnight, being then, on some occasions, equal to a large star of the second magnitude ; decreases during about three months, till it becomes completely invisible...
Page 576 - Uranus and Saturn about the sun; and the correspondence between their calculated and observed places in such very elongated ellipses must be admitted to carry with it proof of the prevalence of the Newtonian law of gravity in their systems, of the very same nature and cogency as that of the calculated and observed places of comets round the central body of our own.
Page 22 - Now, as there is no entire continent, or even any very extensive tract of land, known, whose general elevation above the sea is any thing like half this quantity, it follows, that if we would construct...
Page 259 - What is, moreover, extremely singular in the geology of the moon is, that although nothing having the character of seas can be traced, (for the dusky spots which are commonly called seas, when closely examined, present appearances incompatible with the supposition of deep water,) yet there are large regions perfectly level, and apparently of a decided alluvial character.