The Scientific Library; Or, Repository of Useful and Polite Literature: Comprising Astronomy, Geography, Mythology, Ancient History, Modern History, and Chronology ...S. Wood & Sons, 1818 |
From inside the book
Results 1-5 of 13
Page 26
... parallel to the equator : and as the regular motion of the earth must occasion every place to describe equal parts ... parallels except the equator into two unequal parts , which will have a greater or less portion of their ...
... parallel to the equator : and as the regular motion of the earth must occasion every place to describe equal parts ... parallels except the equator into two unequal parts , which will have a greater or less portion of their ...
Page 27
... parallels into unequal parts , but the phenomena will be directly the contrary ; for all places under the southern parallels will have their days longer than ... parallel , with itself in whatever part of her orbit the earth ASTRONOMY . 27.
... parallels into unequal parts , but the phenomena will be directly the contrary ; for all places under the southern parallels will have their days longer than ... parallel , with itself in whatever part of her orbit the earth ASTRONOMY . 27.
Page 28
... parallel situation , will advance into the illuminated hemisphere , and in June will be about twenty - three and a half degrees from the terminator , the south pole being at the same distance in the dark hemisphere . In this month ...
... parallel situation , will advance into the illuminated hemisphere , and in June will be about twenty - three and a half degrees from the terminator , the south pole being at the same distance in the dark hemisphere . In this month ...
Page 41
... parallel to the equator , the sun - dials and clocks agree , as far as respects this cause , but at other times they are perceived to vary for this ob- vious reason , that equal portions of the eclip- tic . ( on account of its obliquity ) ...
... parallel to the equator , the sun - dials and clocks agree , as far as respects this cause , but at other times they are perceived to vary for this ob- vious reason , that equal portions of the eclip- tic . ( on account of its obliquity ) ...
Page 42
... parallel with the equator . But we have already premised that the elliptic form of the earth's orbit was another cause of the variation between the sun - dial and clocks or watches . Supposing the orbit of our globe to be cir- cular ...
... parallel with the equator . But we have already premised that the elliptic form of the earth's orbit was another cause of the variation between the sun - dial and clocks or watches . Supposing the orbit of our globe to be cir- cular ...
Common terms and phrases
aberration of light altitude annual revolution apparent motion appear Aries ascer ascertain astronomers called cause celestial centre circle comets computed consequently course darkness days and nights degree 15 degree 30 diameter discovered distance diurnal motion diurnal rotation divide Dominical letter earth earth's shadow east eastern side epact equa equal equator equinoctial equinox exactly extends from degree fixed stars full moon golden number gree half happen heavenly bodies heavens horizon isphere Julius Cæsar latitude less Libra light longitude luminary lunar lunar eclipses magni millions of miles minutes month moon's orbit nodes noon north or south north pole northern occasioned opposite parallel passes between degree phere planets Principal star quadrant Rectify the globe refraction satellites seasons second magnitude shadow falls situated solar eclipse south pole southern hemis southern hemisphere southern side sun and moon sun-dial sun's place supposed tides time-piece tion tude turn twelve western young readers
Popular passages
Page 13 - Amid the radiant orbs, That more than deck, that animate the sky, The life-infusing suns of other worlds ; Lo ! from the dread immensity of space Returning, with accelerated course, The rushing comet to the Sun descends ; And as he sinks below the shading earth, With awful train projected o'er the Heavens, The guilty nations tremble.
Page 100 - For I perceived that, if Light was propagated in Time, the apparent Place of a fixed Object would not be the same when ' the Eye is at Rest, as when it is moving in any other Direction, than that of the Line passing through the Eye and the Object ; and that, when the Eye is moving in different Directions, the apparent Place of the Object would be different.
Page 99 - March, 1726, the star was found to be 20" more southwardly than at the time of the first observation. It now, indeed, seemed to have arrived at its utmost limit southward, because, in several trials made about this time, no sensible difference was observed in its situation. By the middle of April it appeared to be returning back again towards the north ; and about the beginning of June it passed at the same distance from the zenith as it had done in December when it was first observed. From the quick...
Page 100 - For I perceived that, if light was propagated in time, the apparent place of a fixed object would not be the same when the eye is at rest, as when it is moving in any other direction than that of the line passing through the eye and...
Page 79 - Eclipses of the sun are more frequent than those of the moon, because his ecliptic limits are greater ; and yet we have more visible eclipses of the moon than of the sun, which is owing to their being seen from all parts of the earth where the moon is above the horizon when the eclipse happens ; whilst those of the sun can only be observed on that small portion of the hemisphere, on which the moon's shadow falls. The greatest number of eclipses, of both luminaries, which can happen in a year, is...
Page 99 - I then endeavoured to find out the cause of them. I was already convinced that the apparent motion of the stars was not owing to a nutation of the earth's axis. The next thing that offered itself was an alteration in the direction of the plumb-line, with which the instrument was constantly rectified; but this upon trial proved insufficient. Then I considered what refraction might do; but here also nothing satisfactory occurred.
Page 26 - ... if the earth's axis were perpendicular to the plane of its orbit, and the excessive variation which would result if the axis were nearly parallel to that plane.