That Meteorite

"Did yon see it ? Did you lienr it V' were the questlons addressed in general conversation duriug Friday and Satur day. No one needed to be told that the " it " referred to was the brilliant meteoric phenomenon of Thursday evening. And to the Tribune otLier questions have come pouring in ; such as - "What was it? Where did it come from ? Where has it gone to ?" It is no wonder that an extraordinary degree of interest was awakened by the unexpected display of celestial pyrotechnics, as it was excepüonally grand and imposing - much more so than any that was ever before witnessed by white men in tkis región. The path of the stranger dnringits visible career may be nearly found from a comparison of the numerous observations made ; thongh many of these are too vague to be of valué in determining position and distan oe, and only one or two give precise information. Erom a comparison of the crude descriptions given, we conclude that the following is an approximate statement of the path pursüed by the meteorite while visible. From some point southwest by west of Lawrence, Kan., to j Miami county, on the eastern border of j that State ; across Missouri, from Cass to Marión counties ; across Illinois, from Adams to Iroquois counties; across Indiana, from the soüthern portion of Newton county to Fort Wayne (Allen oounty), from there across Ohio to the Southern point of Lake Erie, and over the northwe8tern corner of ! vania into New York State. The tance was nearly 1,000 miles ; the time at Chicago about 8h. 35m. p. m., of Dec. 21, 1876 ; the height above the earth's surf ace some seventy-flve miles when over Kansas, to forty miles when over Ohio. lts probable size - of that we may have somethiag to say anon. A line drawn upon the map through the places aboye mdicated wiÜ not be a straight line ; it wül be slightly convex toward the north, but scarcely bends out so much as would a great circle of the sphere if drawn through the east and west extremities of the line. The plane of the visible path, if produced, would pass some distance north from the earth's center. The plane of the motion was inclined about fifteen degrees to the plane of the ecliptic. Our celestial visitor carne to us after even a more extended travel than that of Satan, when (see Job, L, 7) he presen ted himself before the Lord after " going to and fro in the earth, and from walking up and down in it." Our meteorite carne to us from the depths of space ; where, for aught we know, it may have been pursuíng an individual flight during many millions of centuries. The accompaiying diagram will enable our readers to forrn a general idea of the relations of onr visitor, and similar bodies, to the world on which we dweil. The circle, of about 1.4 inches in diameter, representa the earth's orbit. The arrows indícate the directios of her movement, the north pole being above the plan e of the paper. The ellipse represen ts the path of the "meteorite," tho direction of motion being also indicated by arrows. Of course the reader will onderstand that the size of the ellipse, as compared with the esrth's orbit, and the proportion of its longest to its shortest diameter, are not necessarily tliose indicated by the figure. The two orbits intersect at A ; they do not necessarily intersect at any other point, though so representad in the diagram. It is evident that the meteorite may travel around the sun in its prolonged elliptic path, and the earth in her more nearly circular orbit, during countless ages, without once meeting ; just as two ships may cross and recross the Atlantic in opposito directions many times without " sighting " each other - much less col - liding. But if when the earth is at the point A, the meteorite be also very near the cornmon point of intersection, there is then danger of a collision. Whethor they will really collide or not depends upon the circumstances of the oase. The meteorite is traveling at the rate of (say) 20 miles per second, and the earth with a speed of 18; miles (at this time of the year the earth's velocity is a little greater than that); and the earth is continually pulling the stranger toward her by the force of attraction, at a rate which can be rigidly calculated through all the variations in their distance. If, now, we should project (portions of) the two orbits on paper, mark off upon them the place which each body would occupy at successive instants, if there was no mutual attraction, and then set off f rom the meteorite path, toward the earth's places, the clistances through which the body is diawn by the earth's atlraction, we ehould have the actual path of tho meteorite with reference to the earth; and could see by inspection whether the two would collide, or pass each other. In case the meteorite is found to pass into the carth's hemisphere, a further corre ction must be made for the retardation of speed (Jue to ïesistance of the air; and the figure would then show the least dibtauce between the two bodies. There is one facfc which is involved in considering the question whether, under certain geometrical circumstances, the body would fait to the earth or sot - tho character of the material of which it is composed. The friction of the atmosphere retards the motion, and that arrested motion of the inass is converted into motion of its constituent molecules or atoms - it is changed into heat. The teirperature of the body is raised to the point of incandescenoe, and may be increated many thowjanda of degrees. The estertor portions are heafced more rapidly than the interior, as the heat is generated from without ; and this unequal heating causes unequal expansión of the partióles, so that tnere Í8 a continuad tendency to break up from the oatside. The disjoined partióles fall away, and are left behind, because the surface exposed to atmospheric resistance is greater in proportion to the quantity of motion in the ma."S for small bodies than for large ones of the same material. If, now, a large meteorito were composed entirely of iron, the cohesivo attraotion of ita partióles might be (undoubtedly would be)greatenough to rithstand this strain ; and the mass would continue its journey intact, except a comparaüvely small losa by oxidation. If, again, the composition oí the meteorito be somethiug like that of the feet of Nebuchadnezzar's image - which were "pavtly of iron and partly of cluy" - the more " earthy" matter would be broken off, as in the former oase, leaving the iron to fall fis a metallic mass to the earth, or to take another excursión in space, as deterniined by the geometrical relations abo ve desoribed. This appears to have been the composition of the meteor of last July. We remark here that the finding of an iron meteorite by no means pro ves that it was chiefly composed of iron before collision with the earth. lts larger portion of less cohesivo matter may tave been sloughed off in ita passage through the air, and reached the surface of the earth as mere atonas of stardust. We do not 'propose, in this artiole, to enter upon a discussion of the chemical constitution of meteorites, or to describe those which have been found in different parts of the world. All that may be found in the text-books by those who wish to read it. But we ought not to forbear a few words as to the place of these strange bodies in the economy of the universo. Till within a few years past, though the meteorites were believed to have come from outside the earth, yet it was generally thought that there were very few bodies j of matter in the solar systsm except the sun, moon, aeven planeta, some of them haring satellites, and a few comets. We are wiser now. The facts of modern astronomy tend to the conclusión üiat the bodies above referred to are in number comparable with those we cannot see unless when they come near us, as the birds of the air are to the motes which exist all around us, but are only visible when lighted up by a sunbeam. Our latest meteorite, a body of probably more than twenty yards in diameter, is but one of a vast series of individual masses, ranging all the way up from the bulk of a grain of sand to a cloud mass so vast that a ray of light would require three months to flash from one side of it to the opposite. Our earth is a little higher up in the scale than the meteorite, as the sparrow is larger than the gnat, but both are subject to the same laws, own a similar origia, nnd have a similar destiny. Both called out of the original chaos to subserve a certain purpose ; each destüied to destmction when the work is performed for which it was created. The meteorite that rushes blazing through our atmosphere is a world on fire. It is not probable that any living beings are destroyed by the coaflagration, because that little world had long since chilled down past the point at whioh organized forma could exist on its surface. But the earth is passing slowly toward that point, too- aa our racon appears to have already passed it - and when she has ceased to be usef ui, her turn, too, wül come, though inany long eons of death may precede the grand collapse. Analogy warrants the inference that as our meteorite and our groater world "must perish in their turn aud drop to dust," so the sun and stars have the same future bef ore them, in obediencc to the creativo fiat of Him who Sees with cqual eyeB, as Lord of all, A hero perieh or a sparrow fall ; An atoin or a systeru into ruiu iiurled, And now a bob'ble burst, nd then a world.