Youth's Book of AstronomyReed and Barber, 1838 - 256 |
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annual revolution appear ascertained asteroids astronomers atmosphere atmospheric refraction attraction axis balloon called cause celestial body centre Ceres changes circle climate clouds comets consequence constellations dark days and nights degrees diameter difference diminishes direction distance diurnal revolution earth earth's orbit east eclipse effect equal equator feet fixed stars gas balloon globe heavenly bodies heavens height Hence Herschel horizon hourly motion increased inhabitants Jupiter latitude length less longitude lunar eclipse magnitude Mars Mercury meridian millions of miles minutes months move naked eye nearest nearly nebulæ north pole northern hemisphere oblique observations orbit parallax passes penumbra period phenomena planets polar pole proportion Ptolemy quantity rays refraction respect rise satellites Saturn seasons seen shadow shines side Sirius solar eclipse solar system spots sun and moon sun's supposed surface telescope thousand three hundred tides tion tropical velocity Venus Vesta visible whole wind zodiac
Popularne fragmenty
Strona 91 - 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.
Strona 238 - SE leaving an impression upon my mind to which I can give no name, though surely one ingredient in it was fear, with a considerable deal of wonder and astonishment.
Strona 237 - We were here at once surprised and terrified by a sight surely one of the most magnificent in the world. In that vast expanse of desert, from W. and to NW of us, we saw a number of prodigious pillars of sand at different distances, at times moving with great celerity, at others stalking on with a majestic slowness ; at intervals we thought they were coming in a very few minutes to overwhelm us ; and small quantities...
Strona 238 - ... The wind raised the fine sand with which the extensive desert was covered, so as to fill the atmosphere, and render the immense space before us impenetrable to the eye beyond a few yards. The sun and clouds were entirely obscured, and a suffocating and oppressive weight accompanied the flakes and masses of sand, which, I had almost said, we had to penetrate at every step. At times we completely lost sight of the camels, though only a few yards before us.
Strona 64 - Each degree is divided into 60 equal parts called minutes, and each minute into 60 equal parts called seconds.
Strona 119 - Jupiter a moderate-sized orange, in a circle nearly half a mile across; Saturn a small orange, on a circle of four-fifths of a mile...
Strona 119 - Mercury will be represented by a grain of mustard seed, on the circumference of a circle 164 feet in diameter for its orbit ; Venus a pea, on a circle of 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 ; the Asteroids, grains of sand, in orbits of from 1000 to 1200 feet; Jupiter a moderate-sized orange, in a circle nearly half a mile across...
Strona 141 - Stars of the smallest magnitude remain distinctly visible though covered by what appears to be the densest portion of their substance, although the same stars would be completely obliterated by a moderate fog, extending only a few yards from the surface of the earth. And since it is an observed fact that even those larger comets, which have presented the appearance of a nucleus, have yet exhibited no phases, though we cannot doubt that they shine by the reflected solar light, it follows that even...
Strona 154 - Sirius, would require to be removed to 141,400 times its actual distance. We have seen, however, that the distance of Sirius cannot be so small as 200,000 times that of the sun. Hence it follows that, upon the lowest possible computation, the light really thrown out by Sirius cannot be so little as double that emitted by the sun ; or that Sirius must, in point of intrinsic splendour, be at least equal to two suns, and is, in all probability, vastly greater.
Strona 112 - There is not perhaps another object in the heavens that presents us with such a variety of extraordinary phenomena as the planet Saturn ; a magnificent globe, encompassed by a stupendous double ring ; attended by seven satellites ; ornamented with equatorial belts ; compressed at the poles ; turning upon its axis ; mutually eclipsing its ring and satellites, and eclipsed by them ; the most distant of the rings also turning upon its axis, and the same taking place with the farthest of the satellites...