Outlines of astronomy |
From inside the book
Results 1-5 of 100
Page 2
... become en- larged in his imagination into vast globes , the one ap- proaching in magnitude to the earth itself , the other im- mensely surpassing it . The planets , which appear only as stars somewhat brighter than the rest , are to him ...
... become en- larged in his imagination into vast globes , the one ap- proaching in magnitude to the earth itself , the other im- mensely surpassing it . The planets , which appear only as stars somewhat brighter than the rest , are to him ...
Page 11
... become degraded in its application , and confined to superstitious and delusive at- tempts to divine future events by their dependence on pre- Aσtnp , a star ; voμos , a law ; or veμei , to tend , as a shepherd his flock ; so that ...
... become degraded in its application , and confined to superstitious and delusive at- tempts to divine future events by their dependence on pre- Aσtnp , a star ; voμos , a law ; or veμei , to tend , as a shepherd his flock ; so that ...
Page 19
... becomes less obtuse , or , in other words , the apparent angular diameter of the earth diminishes , being nowhere so ... become a tangent to the sphere at m , as is the line xy . ( 23. ) This explains what is meant by the dip of the ...
... becomes less obtuse , or , in other words , the apparent angular diameter of the earth diminishes , being nowhere so ... become a tangent to the sphere at m , as is the line xy . ( 23. ) This explains what is meant by the dip of the ...
Page 29
... becomes visible to him , as if it stood at p , by the refracted ray Part A , to which A p is a tangent . ( 41. ) The exact estimation of the amount of atmospheric refraction , or the strict determination of the angle S As , by which a ...
... becomes visible to him , as if it stood at p , by the refracted ray Part A , to which A p is a tangent . ( 41. ) The exact estimation of the amount of atmospheric refraction , or the strict determination of the angle S As , by which a ...
Page 32
... becomes to us a means of illumination . Such reflective obstacles always exist floating in the air . The whole course of a sun - beam penetrating through the chink of a window - shutter into a dark room is visible as a bright line in ...
... becomes to us a means of illumination . Such reflective obstacles always exist floating in the air . The whole course of a sun - beam penetrating through the chink of a window - shutter into a dark room is visible as a bright line in ...
Other editions - View all
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...