Outlines of AstronomyLongman, Brown, Green, Longmans, 1851 - 661 стор. |
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Сторінка 14
... direction to that of the ship's progress ; but , in reality , they remain at rest , and we leave them behind in the air . Still , the illusion , so far as massive objects and our own movements are concerned , remains complete ; and when ...
... direction to that of the ship's progress ; but , in reality , they remain at rest , and we leave them behind in the air . Still , the illusion , so far as massive objects and our own movements are concerned , remains complete ; and when ...
Сторінка 18
... direction in which a plumb - line * would hang ; for it is an observed fact , that in all situations , in every part of the earth , the direction of a plumb - line is exactly perpendicular to the surface of still water ; and , moreover ...
... direction in which a plumb - line * would hang ; for it is an observed fact , that in all situations , in every part of the earth , the direction of a plumb - line is exactly perpendicular to the surface of still water ; and , moreover ...
Сторінка 26
... their places , which must be rectified by ascertaining the amount and direction of the displacement so apparently produced on each , before we can come at a knowledge of the true directions in 26 OUTLINES OF ASTRONOMY .
... their places , which must be rectified by ascertaining the amount and direction of the displacement so apparently produced on each , before we can come at a knowledge of the true directions in 26 OUTLINES OF ASTRONOMY .
Сторінка 27
... direction of the straight line A S. But , in reality , when the ray of light SA reaches the atmosphere , suppose at d , it will , by the laws of optics , begin to bend downwards , and take a more inclined direction , as d c . This ...
... direction of the straight line A S. But , in reality , when the ray of light SA reaches the atmosphere , suppose at d , it will , by the laws of optics , begin to bend downwards , and take a more inclined direction , as d c . This ...
Сторінка 28
... direction which the visual ray has at the instant of arriving at the eye , without regard to what may have been ... directions around A , the visual ray will not be made to deviate laterally , but will remain constantly in the same ...
... direction which the visual ray has at the instant of arriving at the eye , without regard to what may have been ... directions around A , the visual ray will not be made to deviate laterally , but will remain constantly in the same ...
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Outlines of Astronomy John Frederick William Herschel,Sir John Frederick William Herschel Повний перегляд - 1851 |
Загальні терміни та фрази
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
Популярні уривки
Сторінка 224 - Aries, Taurus, Gemini, Cancer,, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces.
Сторінка 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.
Сторінка 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.
Сторінка 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...
Сторінка 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...
Сторінка 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.
Сторінка 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...
Сторінка 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.
Сторінка 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...
Сторінка 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.