496 PHYSICAL CONSTITUTION OF COMETS. 



parts was thirty times as broad, stretched through the celestial spaces to the 

 enormous distance of one hundred and seventy millions of miles, or about the 

 whole size of the orbit of the earth. Nor were its motions less singular. Un- 

 like any globe connected with the sun. it did not move in a continuous curve, 

 which, like the circle or ellipse, re-enters into itself, and thus constitutes, to 

 the body that has adopted it, a fixed, however eccentric home ; but spying our 

 luminary afar off, as it lay amid those outer abysses, it approached along the 

 arm of a hyperbola, rushed across the orderly orbits of our system into closest 

 neighborhood with the sun, being at that time apart from him only by a sev- 

 enth part of our distance from the moon, and, defying his attraction, by force of 

 its own enormous velocity, which then was nothing less, in one part of its 

 mass, than one third of the velocity of light, it entered on the other divergent 

 arm of its course, and sped toward new immensities. 



" It was when retiring that this unexpected visitant was seen for a brief pe- 

 riod in Europe. In the course of its approach it must have passed between us 

 arid the sun, causing a cometic eclipse, and, in so far, an interception of his 

 heating rays ; but that occurred during our night. 



' And now, what is to be made of this extraordinary apparition ? what is its 

 nature ? what its relations to our system ? and what new revelation does it 

 bring concerning the structure of the universe? Its relations with our system 

 appear to have been few and transitory ; and in this it resembles the probable 

 millions of such masses, that have, since observation began, crossed the plane- 

 tary orbits toward the sun, and, after bending round him, gone in pursuit of 

 some other fixed star. No more than three are known to belong, properly 

 speaking, to the scheme dependant on our luminary Encke's, Biela's, and 

 Halley's ; but though these do revolve around him in fixed periods, the cir- 

 cumstance must be regarded in the light of an accident, their orbits being 

 wholly unlike any other, and having little assurance of stability ; for as they 

 cross the planetary paths, every one of them may yet undergo the fate of Lex- 

 ell's, which, by the action of Jupiter, was first twisted from its diverging orbit 

 into a comparatively short ellipse ; and then, after making two consecutive 

 revolutions around the sun, so that it might have begun to deem itself a den- 

 izen, was, by the same planet twisted back again, and sent off, never to revisit 

 us, away to the chill abysses ! Strange objects, with homes so undefined 

 flying from star to star twisting and winding through tortuous courses, until, 

 perhaps, no depth of that infinite has been untraversed ! What, then, is it your 

 destiny to tell us ? To what new page of that infinite book are you an index? 

 We missed, indeed, only very narrowly, an opportunity of information which 

 might have been not the most convenient; for the earth escaped being involved 

 in the huge tail of our recent visiter, merely by being fourteen ilmjs beiiind it. 

 For one, I should have had no apprehension even in that case, of the realization 

 of geological romances, viz., of our equator being turned to the pole, and the 

 pole to the equator the ocean, meanwhile, leaping from its ancient bed. But 

 if that mist, thin though it was, had, with its next to inconceivable swiftness, 

 brushed across our globe, certainly strange tumults must have occurred in the 

 atmosphere ; and probably no agreeable modification of ihe breathing medium 

 of organic beings. Right, certainly, to be most curious about comers ; but pru- 

 dent, withal, to inquire concerning them from a greater distance than that : al- 

 though one night in November, 1837, I cannot be persuaded that the earth did 

 not venture on a similar, but comparatively small experiment. It was when 

 our globe passed from the peaceful vacant spaces into that mysterious meteor 

 region. The sky became kiflamed and red as blood; coruscations, like auro- 

 ras, darted across it ; not as usual, streaming from one district, but shilling 

 constantly, and sweeping the whole heavens." 



