Popular AstronomyHarper & brothers, 1878 - 571 من الصفحات |
المحتوى
1 | |
8 | |
10 | |
12 | |
15 | |
22 | |
26 | |
27 | |
236 | |
240 | |
241 | |
244 | |
249 | |
250 | |
252 | |
259 | |
38 | |
39 | |
41 | |
42 | |
46 | |
51 | |
55 | |
56 | |
62 | |
63 | |
65 | |
69 | |
74 | |
78 | |
81 | |
83 | |
84 | |
85 | |
86 | |
88 | |
90 | |
91 | |
93 | |
103 | |
105 | |
107 | |
108 | |
110 | |
111 | |
112 | |
116 | |
117 | |
120 | |
121 | |
123 | |
124 | |
125 | |
126 | |
127 | |
129 | |
132 | |
134 | |
137 | |
138 | |
141 | |
148 | |
149 | |
154 | |
155 | |
156 | |
159 | |
164 | |
167 | |
168 | |
169 | |
178 | |
180 | |
181 | |
188 | |
190 | |
193 | |
197 | |
204 | |
212 | |
214 | |
218 | |
220 | |
224 | |
226 | |
235 | |
262 | |
267 | |
275 | |
287 | |
289 | |
292 | |
295 | |
297 | |
304 | |
305 | |
308 | |
309 | |
311 | |
312 | |
319 | |
321 | |
326 | |
328 | |
329 | |
331 | |
339 | |
341 | |
344 | |
346 | |
347 | |
349 | |
351 | |
357 | |
359 | |
361 | |
366 | |
373 | |
375 | |
376 | |
377 | |
378 | |
382 | |
389 | |
392 | |
399 | |
406 | |
413 | |
415 | |
418 | |
425 | |
434 | |
444 | |
449 | |
452 | |
460 | |
468 | |
469 | |
473 | |
486 | |
491 | |
499 | |
501 | |
507 | |
513 | |
519 | |
522 | |
524 | |
529 | |
531 | |
533 | |
535 | |
536 | |
543 | |
567 | |
طبعات أخرى - عرض جميع المقتطفات
عبارات ومصطلحات مألوفة
angle apparent motions appear astronomers atmosphere attraction axis cause celestial equator celestial sphere centre century chromosphere circle comet Copernican system Copernicus dark described determined diameter direction disk distance diurnal motion earth entirely epicycle equator equinox eye-piece focus force glass gravitation heavenly bodies heavens hemisphere Herschel Hipparchus horizon inches instrument Jupiter Kepler known latitude latter length lens light longitude lunar magnifying power Mars mass measuring Mercury meridian method miles minutes mirror moon moon's move nearly night node object observations Observatory orbit parallax pass perihelion photosphere planet planetary pole position prism Ptolemaic system Ptolemy rays reflecting telescope reflector refraction result revolution revolving right ascension ring rotation round satellites Saturn seems seen shown sidereal solar spectroscope spectrum spots star sun's supposed surface telescope theory tion total eclipse transit transit of Venus Uranus vapors velocity Venus visible zenith
مقاطع مشهورة
الصفحة 499 - The secrets of the hoary deep; a dark Illimitable ocean, without bound, Without dimension, where length, breadth, and height, And time, and place, are lost; where eldest Night And Chaos, ancestors of Nature, hold Eternal anarchy, amidst the noise Of endless wars, and by confusion stand.
الصفحة 499 - He rules a moment ; Chaos umpire sits, And by decision more embroils the fray By which he reigns : next him high arbiter Chance governs all. Into this wild abyss, The womb of nature, and perhaps her grave...
الصفحة 81 - 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.
الصفحة 162 - Observer' at a salary of 100£ per annum, his duty being 'forthwith to apply himself with the most exact care and diligence to the rectifying the tables of the motions of the heavens and the places of the fixed stars, so as to find out the so much desired longitude of places for the perfecting the art of navigation.
الصفحة 499 - The womb of Nature, and perhaps her grave, Of neither sea, nor shore, nor air, nor fire, But all these in their pregnant causes mixed Confusedly, and which thus must ever fight, Unless the Almighty Maker them ordain His dark materials to create more worlds...
الصفحة 523 - At the present time we can only say that the nebular hypothesis is indicated by the general tendencies of the laws of nature, that it has not been proved to be inconsistent with any fact, that it is almost a necessary consequence of the only theory by which we can account for the origin and conservation of the sun's heat, but that it rests on the assumption that this conservation is to be explained by the laws of nature as we now see them in operation. Should any one be skeptical as to the sufficiency...
الصفحة 496 - Which of these is the more probable alternative we cannot " pretend to say. That the star can neither be stopped, nor bent " far from its course until it has passed the extreme limit to "which the telescope has ever penetrated, we may consider " reasonably certain. To do this will require two or three millions " of years. Whether it will then be acted on by attractive forces "of which science has no knowledge, and thus carried back to " where it started, or whether it will continue straightforward...
الصفحة 268 - coming down upon us from the north, would, in thirty seconds after they had crossed the St. Lawrence, be in the Gulf of Mexico, carrying with them the whole surface of the continent in a mass, not simply of ruin, but of glowing vapor, in which the vapors arising from the dissolution of the materials composing the cities of Boston, New York, and Chicago would be mixed in a single indistinguishable cloud.
الصفحة 496 - Much the same dilemma may be applied to the past history of this body. If the velocity of 200 miles or more per second with which it is moving exceeds any that could be produced by the attraction of all the other bodies in the universe, then it must have been flying forward through space from the beginning, and having come from an infinite distance, must be now passing through our system for the first and only time.
الصفحة 266 - That the matter of the corona is in what we may call a state of projection, being constantly thrown up by the sun, while each particle thus projected falls down again according to the law of gravitation. The difficulty we encounter here is that we must suppose velocities of projection rising as high as 200 miles per second constantly maintained in every region of the solar globe.