MARS PLANETOIDS JUPITER SATURN URANUS NEPTUNE. 



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globe ; and flying round its primary every twenty-two hours, a rapid succession of phases 

 will be exhibited. But the rings are doubtless the chief glory of the Saturnian firma 

 ment at night, constituting a very noble spectacle, varying in their appearance according 



to the position of the place of observation. 

 From the polar regions they will scarcely be 

 perceptible, but at thirty degrees from the 

 poles a segment of them will be seen emerging 

 above the horizon, increasing in altitude as 

 equatorial latitudes are gained. Supposing 

 them appendages of the earth, the sketch may 

 convey no inaccurate idea of their appearance, at about sixty degrees from the equator. 



Sir John Ross, when in a high 

 northern latitude, observed a striking 

 aurora bestriding the sky, which he 

 describes as answering to his concep 

 tions of the aspect of Saturn's rings as 

 seen from his surface. Advancing to 

 the equator, they will span the heavens 

 like magnificent arches near the ze 

 nith, with the shadow of the planet 

 resting upon them, the satellites 

 pursuing their respective courses at 

 different distances, and the stars 

 shining on each side of the luminous 

 zones, and in the interval between 

 them. 



URANUS. This remote and obscure body, removed to about twice the distance of 

 Saturn from the sun, may be seen with the naked eye by a practised observer in fine 

 weather when the moon is absent, and appears like a fixed star of the least visible 

 magnitude, shining with a pale blue light. It was observed three tunes by Flamstead, 

 once by Bradley, once by Mayer, eleven times by Lemonnier, who registered it among the 

 stai'S ; but Herschel discovered its planetary character at Bath in 1781, and thus effected 

 an achievement, no parallel to which history before had chronicled. For some time 

 previous, astronomers had been aware of the motions of Jupiter and Saturn being subject 

 to certain perturbations which could not be explained ; and it had been conjectured that 

 some planet might revolve beyond the latter, which would account for them. The 

 verification of this idea illustrates the accuracy of astronomical observations. The planet 

 is situated at a mean distance from the sun of 1800 millions of miles, and has a path of 

 more that 10,000 millions to traverse in revolution round him, accomplished in a period 

 of eighty-four years. One circuit therefore has not been performed since it was discovered 

 to be a member of the solar system. It moves over one degree of its orbit in eighty-five 

 days, and is thus seven years in passing one constellation of the zodiac. Uranus, apparently 

 insignificant in the heavens, is the third of the planets in magnitude, eighty times larger 

 than the earth in volume, having a diameter of 35,000 miles. Six satellites, according to 

 Herschel, attend his course. But this observation has not yet been fully verified. No other 

 astronomer obtained a sight of any of these faint objects until the year 1848, when Sir John 

 Herschel detected two, and so far confirmed his father's views. Two more have since been 

 seen by Mr Lassell and M. Otto Struve. They revolve in orbits, the planes of which are 

 nearly perpendicular to the ecliptic, and in a direction from east to west singular 

 anomalies exceptions to the general laws of the system. All the other primary planets 



