210 



METEORS AND FALLING STARS. 



1854.] 



their being luminous bodies which present themselves indepen- 

 dently of the earth's rotation, and penetrate into our atmosphere 

 from without-— from space. The observations of Olmsted proved 

 that in the case of the November falls in 1833, 1834, and 1837, 

 the stars proceeded from the star y Leonis, but in the August 

 fall in 1839, Algol in Perseus, or a point between Perseus and 

 Taurus, was the centre of divergence. According to the accurate 

 observations of Heis, at Aix la Chapelle, as quoted in Vol. I. of 

 the Cosmos, " The falling-stars of the November period present 

 the peculiarity that their paths are more dispersed than those of 

 the August period. In each of the two periods there were simul- 

 taneously several points of departure, by no means always proceed- 

 ing/row the same constellation, as there was too great a tendency to 

 assume since the year 1833." After investigating the paths of 

 407 stars, he found that 171 came from Perseus, 83 from Leo, 

 35 from Cassiopeia, 40 from the Dragon's Head, but full 78 from 

 undetermined points. Schmidt, of Bonn, in a letter to Humboldt 

 (July, 1851), says: "If 1 deduct from the abundant falls of shoot- 

 ing-stars in November 1833 and 1834, as well as from subsequent 

 ones, that kind in which the point in Leo sent out whole swarms 

 of meteors, I am at present inclined to consider the Perseus point 

 as that point of divergence which presents not only in August, 

 but throughout the whole year, the most meteors. This point is 

 situated in Right Ascension 50-3°, and Declension Sl-o (holding 

 good for 1844-6.") He adds, "If the directions of the meteor- 

 paths are considered in their full complication and periodical 

 recurrence, it is found that there are certum points of divergence 

 which are always represented, others which ajspear only sporadi- 

 cally and changeably." 



THEORIES REGARDING THE ORIGIN OF METEORITES AND FALLING- 

 STARS. 



Passing over the opinions of those who attributed meteorites to 

 the effect of lightning in tearing up the earth and converting it 

 into a compact mass, of Aristotle, who considered them masses of 

 stone carried by a hurricane from one locality to another, and of 

 those who have supplied that mysterious region, the North Pole, 

 with an enormous volcano, hurling its eruptions to the distance 

 of many hundred miles, the hypotheses regarding their origin 

 may be reduced to three: 1st. that which makes them of atmo- 

 spheric origin; 2nd. that which gives to them a lunar or plane- 

 tary origin ; and lastly, that which is now generally received as 

 the true one, viz., that they are of cosmical origin. 



The hypotheses respecting the atmospheric origin of these 

 bodies are now generally exploded ; and yet a great deal can be 

 said in their favour. The ablest and most satisfactory paper upon 

 this subject that I have been able to procure, is one written by 

 F. G. Fischer, Esq., in the Berlin Memoirs. It is too long, and 

 discusses too many points, to admit of the compression suitable 

 to a paper like this. He lays down his positions something to 

 this effect: Owing to the many gases and exhalations which are 

 continually evolving at the surface of the earth, many matters 

 exist in the atmosphere which escape chemical investigation, either 

 from the want of tests to denote their presence, from their extreme 

 rarity, or from their accumulating only in the higher regions of 

 the atmosphere, where no experiments can be made. Owing to 

 their extreme lightness, these exhalations ascend with the rapidity 

 of lightning immediately on being disengaged, commingling only 

 when they reach a stratum of air of equal rarity. What becomes 

 of these vapours and gases, which, in the lapse of ages, must be 

 greatly augmented ? " Perhaps," says Mr. Fischer, " falling-stars, 

 fire-balls, northern lights, and meteoric stones are the means by 

 which Nature either transforms them into her own essence or 

 returns them directly to the earth." In the reduction of these 



gases to solids, he has recourse to the agency of electricity, but 

 the modus operandi he attempts not to explain. Kepler held 

 somewhat similar views, and describes fire-balls and shooting- 

 stars as " meteors arising from the exhalations of the earth, and 

 blending with the higher ether." Sir William Hamilton, while 

 giving an account of the great eruption of Vesuvius, in August, 

 1799, ascribes such phenomena to local electrical agency, deve- 

 loped by volcanic ejections. " This kind of electrical fire," says 

 he, " seems to be harmless, and never to reach the ground." (On 

 the improbability that meteoric masses are formed from metal- 

 dissolving gases, which, according to Fusimeri and others, may 

 exist in the highest strata of our atmosphere, and, previously dif- 

 fused through an almost boundless space, may suddenly assume 

 a solid condition, and on the penetration and misceability of gases, 

 Humboldt treats largely in his Relation Historique, vol. i., p. 525.) 



ORIGIN IN LTTNAB VOLCANOES. 



Another opinion is, that aerolites derive their origin from vol- 

 canoes in the moon. Chladni states that an Italian, Paolo Ter- 

 zago, was the first to surmise (1664) that these bodies were of 

 selenic origin. In 1795 Olbers commenced an investigation into 

 the amouut of the initial tangential force that would be requisite 

 to bring to the earth masses projected from the moon ; and the 

 mathematical possibility of a sufficient force existing, together 

 with the then prevalent opinion of there being active volcanoes 

 in the moon, led to the belief in some minds of the physical proba- 

 bility of such an origin. La Place, Biot, Brandes, and Poisson 

 all gave considerable attention to this ballistic problem, as Hum- 

 boldt designates it. Olbers, Brandes, and Chladni thought "that 

 the velocity of 16 to 32 miles, with which fire-balls and shooting- 

 stars entered our atmosphere," furnished a refutation to the view 

 of their selenic origin. Setting aside the resistance of the air, 

 an initial velocity of 8292 feet in a second would be required, 

 according to Olbers; to La Place, 7862; to Biot, 8282; and to 

 Poisson, 7595. Olbers has shown "that, with an initial velocity 

 of 8000 feet in a second, meteoric stones would arrive at the sur- 

 face of the earth with a velocity of only 35,000 feet. But the 

 measured velocity of meteoric stones averages five times that 

 amount, or upward of 114,000 feet to a second, and, consequently, 

 the original velocity of projection from the moon must be almost 

 110,000 feet, or fourteen times greater than La Place asserted." 

 — [Cosmos, vol. i., p. 121.) 



La Place, in one portion of his great book, cautiously observes 

 that aerolites, " in all probability, come from the depths of space," 

 but elsewhere inclines to the hypothesis of their lunar origin — 

 assuming, however, that the stones projected from the moon 

 "become satellites of our earth, describing around it more or less 

 eccentric orbits, and thus not reaching its atmosphere until several, 

 or even many revolutions have been accomplished." The distin- 

 guished chemist Berzelius has examined this hypothesis at great 

 length, and adopts it on grounds which he finds in the chemical 

 constitution and mineralogical character of these bodies. His 

 arguments, which are copied in the Edinburgh new Philosophical 

 Journal, are exceedingly ingenious, but still they are built on 

 hypothetical conjectures which can be met and answered. Von 

 Ende Beuzenberg and others coincide in his general views. The 

 great velocity of these bodies, however, as well as the direction of 

 their orbits, which, is often opposite to that of the earth, are now 

 regarded as conclusive arguments against this hypothesis. In 

 connection with this, I may just name the opinion of Olbei-s and 

 those who consider these meteoric bodies the debris or fragments 

 of a large planet which had burst, and of which the asteroids are 

 the remaining portions. The smaller fragments continue to c r- 

 culate about the sun in orbits of great eccentricity, and when they 



