A Treatise on AstronomyLea & Blanchard, 1842 - 411 pages |
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Common terms and phrases
altitude amount angle angular appear arise ascer ascertained astronomical atmosphere axis body calculation called cause celestial centre centrifugal force circle clock comet course degree described determined deviation difference direction disc distance diurnal motion double stars earth earth's surface eccentricity ecliptic ellipse equal equator equinoctial equinox error exact fixed force former globe gravity greater heavens heliocentric hemisphere horizon inferior planet instance instrument interval Jupiter known latitude latter law of Kepler less longitude lunar mass mean measure meridian moon moon's mural circle nature nearly node nutation object observed orbit parallax passing perihelion period planet polar pole portion position proportion radius rays reader reckoning refraction respect revolution revolving right ascension rotation round satellites Saturn seen side sidereal sidereal period situation solar spectator sphere spherical stars station sun's suppose telescope tion triangle Uranus velocity visible weight whole zenith
Popular passages
Page 213 - 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 183 - They commence at the vernal equinox, and are named in order — Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricornus, Aquarius, Pisces.* They are denoted also by the following symbols : — <y>j 8, n , 93, SI, ITR, A, -n\_, / , Vj", *:, X.
Page 334 - Useful, it is true, they are to man as points of exact and permanent reference ; but he must have studied astronomy to little purpose, who can suppose man to be the only object of his Creator's care, or who does not see in the vast and wonderful apparatus around us provision for other races of animated beings.
Page xi - In entering upon any scientific pursuit, one of the student's first endeavors ought to be to prepare his mind for the reception of truth, by dismissing, or at least loosening his hold on, all such crude and hastily adopted notions respecting the objects and relations he is about to examine, as may tend to embarrass or mislead him...
Page 189 - 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 those of terrestrial magnetism and the aurora.
Page xi - ... of a nature 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 210 - ... immediate consciousness of effort, when we exert force to put matter in motion, or to oppose and neutralize force, which gives us this internal conviction of power and causation so far as it refers to the material world, and compels us to believe that whenever we see material objects put in motion from a state of rest, or deflected from their rectilinear paths and changed in their velocities if already in motion, it is in consequence of such an EFFORT somehow exerted, though not accompanied with...
Page 361 - Every year whose number is not divisible by 4 without remainder, consists of 365 days ; every year which is so divisible, but is not divisible by 100, of 366 ; every year divisible by 100, but not by 400, again of 365 ; and every year divisible by 400, again of 366.
Page 346 - This earth ? reciprocal, if land be there, Fields and inhabitants. Her spots thou seest As clouds, and clouds may rain, and rain produce Fruits in her soften'd soil, for some to eat Allotted there ; and other suns, perhaps, With their attendant moons, thou wilt descry, Communicating male and female light, Which two great sexes animate the world, Stored in each orb, perhaps, with some that live...
Page xviii - ... to place under his inspection that central thread of common sense on which the pearls of analytical research are invariably strung; but which, by the attention the latter claim for themselves, is often concealed from the eye of the gazer, and not always disposed in the straightest and most convenient form to follow by those who string them.