Chambers's Edinburgh Journal, No. 450, page 29 by Various Authors
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skies. Having once shewn themselves there, and vanished, they are lost to us for ever. They are but stray and chance visitors to the domains of our sun, and refuse to submit themselves, with the more regular members of their fraternity, to the regulation-arrangements of our system, or to appear punctually at the systematic roll-call therein instituted. They are the true free-wanderers of the Infinite, passing from shore to shore of immensity, and presenting themselves, for short and uncertain intervals, to star after star. When they flit through our skies, they shew themselves in all possible positions, and move along all possible directions. They sometimes, however, yield too much to temptation, and have to suffer the penalty of a short imprisonment in consequence. Lexell's Comet, for instance, rushed in its hyperbolic path too near to Jupiter, and was caught in the attraction of its mass, and made to dance attendance on the sun through two successive elliptical revolutions. At the end of the second, the influence that had impounded the comet came, however, into play oppositely, and restored it again to its wandering life and hyperbolic courses. Its cloudy form has not presented itself amongst our stars since 1770, when its visit was thus strangely received by Jupiter.
Twenty-three comets were seen by the naked eye during the sixteenth century, 12 were seen in the seventeenth, 8 in the eighteenth, and 9 in the first half of the nineteenth. This does not, however, give anything like an adequate idea of the number of comets really in existence. When Kepler was asked how many comets he thought there were, he answered: 'As many as there are fishes in the sea.' And modern science seems determined, that the sagacious German shall not be at fault even in this predication. Two or three fresh telescopic comets are now usually found out every year. In 1847, 178 comets were known to be moving in parabolic orbits, and therefore to be in some way permanent connections of our world-system. Lalande has enumerated 700 c