Outlines of astronomy |
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Page xix
... Meridian circle . Fixation of polar and horizontal points . The level , plumb- line , artificial horizon . Principle of collimation . Collimators of Rittenhouse , Kater , and Bohnenberger . Of compound instruments with co - ordinate ...
... Meridian circle . Fixation of polar and horizontal points . The level , plumb- line , artificial horizon . Principle of collimation . Collimators of Rittenhouse , Kater , and Bohnenberger . Of compound instruments with co - ordinate ...
Page 58
... meridian of a station on the earth's surface , is a great circle of the globe passing through both poles and through the place . The plane of the meridian is the plane in which that circle lies . ( 86. ) DEF . 5. The sensible and the 58 ...
... meridian of a station on the earth's surface , is a great circle of the globe passing through both poles and through the place . The plane of the meridian is the plane in which that circle lies . ( 86. ) DEF . 5. The sensible and the 58 ...
Page 59
... meridian line is the line of intersection of the plane of the meridian of any station with the plane of the sensible horizon , and therefore marks the north and south points of the horizon , or the directions in which a spectator must ...
... meridian line is the line of intersection of the plane of the meridian of any station with the plane of the sensible horizon , and therefore marks the north and south points of the horizon , or the directions in which a spectator must ...
Page 62
... meridian of a spectator is the great circle marked out on the sphere by the prolongation of the plane of his terrestrial meridian . If the earth be sup- posed at rest , this is a fixed circle , and all the stars are carried across it in ...
... meridian of a spectator is the great circle marked out on the sphere by the prolongation of the plane of his terrestrial meridian . If the earth be sup- posed at rest , this is a fixed circle , and all the stars are carried across it in ...
Page 63
... meridian of the place of observation . We shall always reckon it positively from the upper culmination ( art . 125. ) westwards , or in conformity with the apparent diurnal motion , completely round the circle from 0 ° to 360 ° . Hour ...
... meridian of the place of observation . We shall always reckon it positively from the upper culmination ( art . 125. ) westwards , or in conformity with the apparent diurnal motion , completely round the circle from 0 ° to 360 ° . Hour ...
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Common terms and phrases
61 Cygni amount angle angular appear apsides ascertained astronomers attraction axis bright calculation celestial Centauri circle comet Cygni described diameter difference direction disc distance disturbing force Ditto diurnal diurnal motion double stars earth ecliptic effect epoch equal equator equinoctial equinox error exact excentricity fixed globe gravity greater heavens hemisphere horizon inclination increase instance interval Julian period Jupiter latitude latter length less light longitude lunar magnitude mass mean measure meridian micrometrical moon moon's nearly nebula node normal force nutation object observed orbit Orionis parallax parallel perihelion period perturbations phænomena phænomenon planet planetary pole portion position precisely proper motion proportion reckoned refraction remarkable respect result revolution right ascension rotation round satellites Saturn seen sidereal sidereal day situation solar solar apex sphere spherical station sun's suppose surface syzygies tangential force telescope tion Uranus variation velocity visible whole
Popular passages
Page 241 - Aries, Taurus, Gemini, Cancer,, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces.
Page 294 - 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 351 - On the other hand, in the regions beneath the dark side, a solar eclipse of fifteen years in duration, under their shadow, must afford (to our ideas) an inhospitable asylum to animated beings, ill compensated by the faint light of the satellites. But we shall do wrong to judge of the fitness or unfitness of their condition from what we see around us, when, perhaps, the very combinations which convey to our minds only images of horror, may be in reality theatres of the most striking and glorious displays...
Page 259 - 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 353 - 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.
Page 58 - 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 285 - The consequence must be absolute aridity below the vertical sun, constant accretion of hoar frost in the opposite region, and, perhaps, a narrow zone of running water at the borders of the enlightened hemisphere. It is possible, then, that evaporation on the one hand, and condensation on the other, may to a certain extent preserve an equilibrium of temperature, and mitigate the extreme severity of both climates.
Page xxv - ... adverse to notions he may have previously formed for himself, or taken up, without examination, on the credit of others. Such an effort is, in fact, a commencement of that intellectual discipline which forms one of the most important ends of all science. It is the first movement of approach...
Page 353 - 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...