LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA 
 
 GIFT OF 
 
 Class 
 
BY THE AUTHOR OF THIS VOLUME. 
 
 METEORIC ASTRONOMY: 
 
 A TREATISE ON 
 
 SHOOTING STARS, FIRE BALLS, 
 AND AEROLITES. 
 
 BY DANIEL KIRKWOOD, LL.D. 
 
 12mo. Extra Cloth. $1.5O. 
 
 * # * For sale by Booksellers generally, or will be sent by mail, 
 postpaid, on receipt of the price by 
 
 J, B, LIPPINCOTT & 00,, Publishers, 
 
 715 and 717 Market St., Philadelphia. 
 
Fig. 1. 
 
 THE SOLAR SYSTEM. 
 
 [Frontispiece.] 
 
COMETS AND METEORS 
 
 THEIR PHENOMENA IN ALL AGES; 
 
 THEIR MUTUAL RELATIONS; 
 
 THEORY OF THEIR ORIGIN. 
 
 BY 
 
 DANIEL KIRK WOOD, LL.D., 
 
 PROFESSOR OF MATHEMATICS IN INDIANA UNIVERSITY, AND AUTHOR OF " METEORIC 
 ASTRONOMY." 
 
 PHILADELPHIA: 
 
 J. B. LIPPINCOTT & CO. 
 
 1873. 
 
Entered according to Act of Congress, in the year 1873, by 
 
 DANIEL KIRKWOOD, LL.D., 
 In the Office of the Librarian of Congress at Washington. 
 
te. 
 
 PREFACE. 
 
 THE origin of meteoric astronomy, as a science, 
 dates from the memorable star-shower of 1833. 
 Soon after that brilliant display it was found that 
 similar phenomena had been witnessed, at nearly 
 regular intervals, in former times. This discovery 
 led at once to another no less important, viz. : that 
 the nebulous masses from which such showers are 
 derived revolve about the sun in paths intersecting 
 the earth's orbit. The theory that these meteor- 
 clouds are but the scattered fragments of disin- 
 tegrated comets was announced by several astron- 
 omers in 1867: a theory confirmed in a remark- 
 able manner by the shower of meteors from the 
 debris of Biela's comet on the^ 27th of November, 
 1872. 
 
 To gratify the interest awakened in the public 
 mind by the discoveries here named, is the main 
 design of the following work. Among the subjects 
 considered are, cometary astronomy ; aerolites, with 
 the phenomena attending their fall; the most bril- 
 
 3 
 
 219378 
 
4 PREFACE. 
 
 liant star-showers of all ages; and the origin of 
 comets, aerolites, and falling stars. 
 
 It may be proper to remark that the language 
 used by the writer in a volume* published several 
 years since, and now nearly out of print, has been 
 occasionally adopted in the following treatise. 
 
 BLOOMINGTON, INDIANA, April, 1873. 
 
 * Meteoric Astronomy. 
 
CONTENTS. 
 
 PREFACE 
 
 CHAPTER I. 
 A GENERAL VIEW or THE SOLAR SYSTEM .... 9 
 
 CHAPTER II. 
 
 COMETS 13 
 
 COMETS VISIBLE IN THE DAY-TIME . . . . .15 
 PERIODIC COMETS^ 18 
 
 CHAPTER III. 
 
 COMETS WHOSE ELEMENTS INDICATE PERIODICITY, BUT 
 WHOSE RETURNS HAVE NOT BKKN RECOGNIZED . . 31 
 
 CHAPTER IV. 
 OTHER REMARKABLE COMETS 39 
 
 CHAPTER V. 
 THE POSITION AND ARRANGEMENT OF COMETARY ORBITS 43 
 
 CHAPTER VI. 
 THE DISINTEGRATION OF COMETS 49 
 
 CHAPTER VII. 
 
 METEORIC STONES 57 
 
 1* 5 
 
CONTENTS. 
 
 CHAPTER VIII. 
 
 PAOE. 
 
 SHOOTING-STARS METEORS OF NOVEMBER 14 . 69 
 
 CHAPTER IX. 
 OTHER METEORIC STREAMS 82 
 
 CHAPTER X. 
 THE ORIGIN OF COMETS AND METEORS 94 
 
I. 
 
 COMETS. 
 
COMETS AND METEORS. 
 
 CHAPTER I. 
 
 A GENERAL VIEW OF THE SOLAR SYSTEM. 
 
 4) 
 
 A DESCRIPTIVE treatise on COMETS and METEORS 
 may properly be preceded by a brief general view 
 of the planetary system to which these bodies are 
 related, and by which their motions, in direction 
 and extent, are largely influenced. 
 
 THE SOLAR SYSTEM consists of the sun, together 
 with the planets, comets, and meteors which revolve 
 around it as the centre of their motions. The sun 
 is the great controlling orb of this system, and the 
 source of light and heat to its various members. 
 Its magnitude is one million three hundred thou- 
 sand times greater than that of the earth, and" it 
 contains more than seven hundred times as much 
 matter as all the planets put together. 
 
 Mercury is the nearest planet to the sun; its 
 mean distance being about 35,400,000 miles. Its 
 diameter is 3000 miles, and it completes its orbital 
 revolution in 88 days. 
 
 Venus, the next member of the system, is some- 
 times our morning and sometimes our evening star. 
 Its magnitude is almost exactly the same as that of 
 the earth. It revolves round the sun in 225 days. 
 
 9 
 
10 COMETS AND METEORS. 
 
 The earth is the third planet from the sun in 
 the order of distance ; the radius of its orbit being 
 about 92,000,000 miles. It is attended by one sat- 
 ellite, the moon, the diameter of which is 2160 
 miles. 
 
 Mars is the first planet exterior to the earth's 
 orbit. It is considerably smaller than the earth, 
 and has no satellite. It revolves round the sun in 
 687 days. 
 
 The Asteroids. Since the commencement of the 
 present Century a remarkable zone of telescopic 
 planets has been discovered immediately exterior to 
 the orbit of Mars. These bodies are extremely 
 small; some of them probably containing less mat- 
 ter than the largest mountains on the earth's sur- 
 face. 131 members of the group are known at 
 present, and the number is annually increasing. 
 
 Jupiter, the first planet exterior to the asteroids, 
 is nearly 500,000,000 miles from the sun, and re- 
 volves round it in a little less than 12 years. This 
 planet is 86,000 miles in diameter, and contains 
 more than twice as much matter as all the other 
 planets, primary and secondary, put together. Ju- 
 piter is attended by four moons or satellites. 
 
 Saturn is the sixth of the principal planets in the 
 order of distance. Its orbit is about 400,000,000 
 miles beyond that of Jupiter. This planet is at- 
 tended by eight satellites, and is surrounded by 
 three broad flat rings. Saturn is 73,000 miles in 
 diameter, and its mass or quantity of matter is more 
 than that of all the other planets except Jupiter. 
 
 Uranus is at double the distance of Saturn, or 
 nineteen times that of the earth. Its diameter is 
 
A GENERAL VIEW OF THE SOLAR SYSTEM. 11 
 
 about 34,000 miles, and its period of revolution 84 
 years. It is attended by at least four satellites. 
 
 Neptune is the most remote known member of 
 the system; its distance being 2,800,000,000 miles. 
 It is somewhat larger than Uranus; has certainly 
 one satellite, and probably several more. Its period 
 is about 165 years. A cannon-ball flying outward 
 from the sun at the uniform velocity of 500 miles 
 per hour would not reach the orbit of Neptune in 
 less than 639 years. 
 
 These planets all move round the sun in the same 
 direction, from west to east. Their motions are 
 nearly circular, and also nearly in the same plane. 
 Their orbits, except that of Neptune, are repre- 
 sented in the frontispiece. It is proper to remark, 
 however, that all representations of the solar system 
 by maps and planetariums must give an exceedingly 
 erroneous view either of the magnitudes or dis- 
 tances of its various members. If the earth, for 
 instance, be denoted by a ball half an inch in di- 
 ameter, the diameter of the sun, according to the 
 same scale (16,000 miles to the inch), will be between 
 four and five feet; that of the earth's orbit, about 
 1000 feet; while that of Neptune's orbit will be 
 nearly six miles. To give an accurate representa- 
 tion of the solar system at a single view is therefore 
 plainly impracticable. 
 
 THE ZODIACAL LIGHT. This term was first applied 
 by Dominic Cassini, in 1683, to a faint nebulous 
 aurora, somewhat resembling the milky way, ap- 
 parently of a conical or lenticular form, having its 
 base toward the sun and its axis nearly in the di- 
 rection of the ecliptic. The most favorable time for 
 
12 COMETS AND METEORS. 
 
 observing it is when its axis is most nearly perpen- 
 dicular to the horizon. This, in our latitudes, oc- 
 curs in March, for the evening, and in October, for 
 the morning. The angular distance of its vertex 
 from the sun is frequently seventy or eighty de- 
 grees, while sometimes, though rarely (except within 
 the tropics), it exceeds even one hundred degrees. 
 It was noticed in the latter part of the 16th century 
 by Tycho Brahe. The first accurate description of 
 the phenomenon was given, however, by Cassini. 
 This astronomer supposed the appearance to be pro- 
 duced by the blended light of innumerable bodies 
 too small to be separately observed, a theory still 
 very generally accepted. In other words, the zo- 
 diacal light is probably a swarm of infinitesimal 
 planets;^ the greater part of the cluster being inte- 
 rior to Mercury's orbit. 
 
 The distances between the different members of 
 our planetary system, vast as they may seem, sink 
 into insignificance when compared with the inter- 
 vals which separate us from the so-called fixed stars. 
 Alpha Centauri, the nearest of those twinkling lu- 
 minaries, is 7000 times more distant than Neptune 
 from the sun. Even light itself, which moves 
 185,000 miles in a second, is more than three years 
 in traversing the mighty interval. 
 
CHAPTER II. 
 
 COMETS. 
 
 THE term comet which signifies literally a hairy 
 star may be applied to all bodies that revolve about 
 the sun in very eccentric orbits. The sudden ap- 
 pearance, vast dimensions, and extraordinary aspect 
 of these celestial wanderers, together with their rapid 
 and continually varying motions, have never failed 
 to excite the attention and wonder of all observers. 
 Nor is it surprising that in former times, when the 
 nature of their orbits was wholly unknown, they 
 should have been looked upon as omens of impend- 
 ing evil, or messengers of an angry Deity. Even 
 now, although modern science has reduced their 
 motions to the domain of law, determined approxi- 
 mately their orbits, and assigned in a number of 
 instances their periods, the interest awakened by 
 their appearance is in some respects still unabated. 
 
 The special points of dissimilarity between planets 
 and comets are the following: The former are 
 dense, and, so far as we know, solid bodies; the 
 latter are many thousand times rarer than the earth's 
 atmosphere. The planets all move 'from west to 
 east; many comets revolve in the opposite direction. 
 The planetary orbits are but slightly inclined to the 
 plane of the ecliptic; those of comets may have any 
 inclination whatever. *The planets are observed in 
 
 2 13 
 
14 COMETS AND METEORS. 
 
 all parts of their orbits; comets, only in those parts 
 nearest the sun. 
 
 The larger comets are attended by a tail, or train 
 of varying dimensions, extending generally in a 
 direction opposite to that of the sun. The more 
 condensed part, from which the tail proceeds, is 
 called the nucleus; and the nebulous envelope imme- 
 diately surrounding the nucleus is sometimes termed 
 the coma. These different parts are seen in Fig. 2, 
 which represents the great comet of 1811. 
 
 Zeno, Democritus, and other Greek philosophers 
 held that comets were produced by the collection of 
 several stars into clusters. Aristotle taught that 
 they were formed by exhalations, which, rising from 
 the earth's surface, ignited in the upper regions of 
 the atmosphere. This hypothesis, through the great 
 influence of its author, was generally received for 
 almost two thousand years. Juster views, however, 
 were entertained by the celebrated Seneca, who 
 maintained that comets ought to be ranked among 
 the permanent works of nature, and that their dis- 
 appearance was not an extinction, but simply a 
 passing beyond the reach of our vision. The ob- 
 servations of Tycho Brahe first established the fact 
 that comets move through the planetary spaces far 
 beyond the limits of our atmosphere. The illustrious 
 Dane, however, supposed them to move in circular 
 orbits. Kepler, on the other hand, was no less in 
 error in considering their paths to be rectilinear. 
 James Bernoulli supposed comets to be the satel- 
 lites of a very remote planet, invisible on account 
 of its great distance, such satellites being seen only 
 in the parts of their orbits ifearest the earth. Still 
 
THE GREAT COMET OY 1811. 
 
 rage II. 
 
COMETS. 15 
 
 more extravagant was the hypothesis of Descartes, 
 who held that they were originally fixed stars, which, 
 having gradually lost their light, could no longer 
 retain their positions, but were involved in the vor- 
 tices of the neighboring stars, when such as were 
 thus brought within the sphere of the sun's illumi- 
 nating power again became visible. 
 
 Comets visible in the daytime. 
 
 Comets of extraordinary brilliancy have some- 
 times been seen during the daytime. At least 
 thirteen authentic instances of this phenomenon 
 have been recorded in history. The first was the 
 comet which appeared about the year 43 B.C., just 
 after the assassination of Julius Csesar. The Romans 
 called it the Julium Sidus, and regarded it as a celes- 
 tial chariot sent to convey the soul of Caesar to the 
 skies. It was seen two or three hours before sunset, 
 and continued visible for eight successive days. The 
 great comet of 1106, described as an object of ter- 
 rific splendor, was seen simultaneously with the sun, 
 and in close proximity to it. Dr. Halley supposed 
 this and the Julian comet to have been previous 
 visits of the great comet of 1680. In the year 1402 
 two comets appeared, one about the middle of 
 February, the other in June, both of which were 
 visible while the sun was above the horizon. One 
 was of such magnitude and brilliancy that the 
 nucleus and even the tail could be seen at midday. 
 The comet of 1472, one of the most splendid re- 
 corded in history, was visible in full daylight, when 
 nearest the earth, on the 21st of January. This 
 
16 COMETS AND METEORS. 
 
 comet, according to Laugier, moves very nearly in 
 the plane of the ecliptic, its inclination being less 
 than two degrees. Its least distance from our globe 
 was only 3,300,000 miles. The comet of 1532, sup- 
 posed by some to be identical with that of 1661, was 
 also visible in full sunshine. The apparent magni- 
 tude of its nucleus was three times greater than that 
 of Jupiter. The comet of 1577 was seen with the 
 naked eye by Tycho Brahe before sunset. It was 
 by observations on this body that Aristotle's doc- 
 trine in regard to the origin, nature, and distance 
 of comets was proved to be erroneous. It was 
 simultaneously observed by Tycho at Oranienberg, 
 and Thaddeus Hageeius at Prague; the points of 
 observation being more than 400 miles apart, and 
 nearly on the same meridian. The comet was found 
 to have no sensible diurnal parallax; in other words, 
 its apparent place in the heavens was the same to 
 each observer, which could not have been the case 
 had the comet been less distant than the moon. The 
 comet which passed its perihelion on the 8th of No- 
 vember, 1618, was distinctly seen by Marsilius when 
 the sun was above the horizon. The great comet 
 of 1744 was seen without the aid of a glass at one 
 o'clock in the afternoon, only five hours after its 
 perihelion passage. The diameter of this body was 
 nearly equal to that of Jupiter. It had six tails, the 
 greatest length of which was about 30,000,000 miles, 
 or nearly one-third of the distance of the earth from 
 the sun. The spaces between the tails were as dark 
 as the rest of the heavens, while the tails themselves 
 were bordered with a luminous edging of great 
 beauty. 
 
COMETS. 17 
 
 The great comet of 1843 was distinctly visible to 
 the naked eye, at noon, on the 28th of February. 
 It appeared as a brilliant body, within less than two 
 degrees from the sun. This comet passed its peri- 
 helion on the 27th of February, at which time its 
 distance from the sun's surface was only about one- 
 fourth of the moon's distance from the earth. This 
 is the nearest approach to the sun ever made by any 
 known comet. The velocity of the body in peri- 
 helion was about 1,280,000 miles an hour, or nearly 
 nineteen times that of the earth in its orbit. The 
 apparent length of its tail was sixty-five degrees, and 
 its true length 150,000,000 miles. The first comet 
 of 1847, discovered by Mr. Hind, was also seen near 
 the sun on the day of its perihelion passage. That 
 discovered by Klinkerfues on the 10th of June, 1853, 
 and which passed its perihelion on the 1st of Sep- 
 tember, was seen at Olmutz in the daytime, August 
 31, when only twelve degrees from the sun. After 
 passing its perihelion, it was again observed, at noon, 
 on the 2d, 3d, and 4th of September. Finally, the 
 great comet of 1861 was seen before sunset, on 
 Monday evening, July 1, by Rev. Henry W. Ballan- 
 tine, of Bloomington, Indiana. It was again de- 
 tected on the following evening just as the sun was 
 in the horizon. 
 
 Besides the thirteen comets which we have enu- 
 merated, at least four others have been seen in 
 the daytime; all, however, under peculiar circum- 
 stances. Seneca relates that during a great solar 
 eclipse, 63 years before our era, a large comet was 
 observed not far from the sun. "Philostorgius 
 says that on the 19th of July, A. D. 418, when 
 
 2* 
 
18 COMETS AND METEORS. 
 
 the sun was eclipsed and stars were visible, a great 
 comet, in the form of a cone, was discovered near 
 that luminary, and was afterwards observed during 
 the nights/'* The comet which passed its peri- 
 helion on the 18th of November, 1826, was observed 
 by both Gambart and Flaugergues to transit the 
 solar disk, the least distance of the nucleus from 
 the sun's surface being about 2,000,000 miles. The 
 second comet of 1819 and the comet of 1823 are 
 both known in like manner to have passed between 
 the sun and the earth. Unfortunately, however, 
 the transits were not observed. 
 
 A few cometary orbits are hyperbolas, more 
 ellipses, and a still greater number parabolas. 
 Comets moving in ellipses remain permanently 
 within the limits of solar influence. Others, how- 
 ever, visit our system but once, and then pass offio 
 wander indefinitely in the sidereal spaces. 
 
 Comets of known periodicity. 
 
 I. Halley's Comet. 
 
 As comets are subject to great changes of appear- 
 ance, one can never be identified by any description 
 of its magnitude, brilliancy, etc., at the time of a 
 previous return. This can be done only by a com- 
 parison of orbits. If, for example, we find the ele- 
 ments of an orbit very nearly corresponding in every 
 particular with those of a former comet, there is a 
 degree of probability, amounting almost to cer- 
 
 * Hind. 
 
19 
 
 tainty, that the two are identical. Sir Isaac Newton, 
 in his Principia, published shortly after the appear- 
 ance of the comet of 1682, explained how the periods 
 of those mysterious visitors might thus be ascer- 
 tained, thus directing the attention of astronomers 
 to the subject. Dr. Halley soon after undertook a 
 thorough discussion of all the recorded cometary 
 observations within his reach. In the course of his 
 investigations he discovered that the path of the 
 comet observed by Kepler in 1607 coincided almost 
 exactly with that of the one which passed its peri- 
 helion in 1682. Hence he concluded that they were 
 the same. He found also that the comet of 1531, 
 whose course had been particularly observed by 
 Apian, moved in the same path. The interval 
 between the consecutive appearances being nearly 
 76 years, Halley announced this as the time of 
 the comet's revolution, and boldly predicted its 
 return in 1758 or 1759. The law of universal gravi- 
 tation had at this time just been discovered and 
 announced. But although its application to the 
 determination of planetary and cometary perturba- 
 tions had not been developed, Halley was well aware 
 that the attractive influence of Jupiter and Saturn 
 might accelerate or retard the motion of the cornet, 
 so as to produce a considerable variation in its period. 
 During the interval from 1682 to 1759, the applica- 
 tion of the higher mathematics to problems in physi- 
 cal astronomy had been studied with eminent suc- 
 cess. The disturbing effect of the two large planets, 
 Jupiter and Saturn, was computed with almost 
 incredible labor by Clairaut, Lalande, and Madame 
 Lepaute. The result as announced by Clairaut to 
 
20 COMETS AND METEORS. 
 
 the Academy of Sciences in November, 1758, was 
 that the period must be 618 days longer than that 
 immediately preceding, and that the comet accord- 
 ingly would pass its perihelion about the 13th of 
 April, 1759. It was stated, however, that, being 
 pressed for want of time, they had neglected certain 
 quantities which might somewhat affect the result. 
 The comet, in fact, passed its perihelion in March, 
 within less than a month of the predicted time. 
 When it is considered that the attraction of the 
 earth was not taken into the account, and that 
 Uranus, whose influence must have been sensible, 
 had not then been discovered, this must certainly 
 be regarded as a remarkable approximation. 
 
 But during the next interval of 76 years the theory 
 of planetary perturbations had been more perfectly 
 developed. The masses of Jupiter and Saturn had 
 been determined with greater accuracy, and Uranus 
 had been added to the known members of the plan- 
 etary system. A nearer approximation to the exact 
 time of the comet's perihelion passage in 1835 was 
 therefore to be expected. Prizes were offered by 
 two of the learned societies of Europe the Academy 
 of Sciences at Turin, and the French Institute for 
 the most perfect discussion of its motions. That of 
 the former was awarded to Damoiseau, that of the 
 latter to Pontecoulant. The times assigned by these 
 distinguished mathematicians for the comet's peri- 
 helion passage were very nearly the same, and dif- 
 fered but a few days from the true time. Had the 
 present received mass of Jupiter been used in the 
 calculations, Pontecoulant, it is believed, would not 
 have been in error as much as 24 hours. It may be 
 
HALLEY'S COMET. 21 
 
 proper to remark that, during the entire period from 
 1759 to 1835, the position of Neptune was such that 
 it could produce no considerable effect on the motion 
 of the comet. 
 
 This interesting object will again return about 
 1911. 
 
 The visit of 1531 was the earliest that Halley suc- 
 ceeded in determining with any degree of certainty. 
 Peter Apian, by whom it was at that time observed, 
 was the first European to ascertain the fact that, as 
 a general thing, the tails of comets are turned from 
 the sun.* To confirm this discovery, he carefully 
 followed the body in its progress through the con- 
 stellations. By means of his recorded observations 
 Halley was enabled to identify this comet with that 
 of 1607 and 1682. The great comet of 1456 he con- 
 jectured to be the same, from the date of its appear- 
 ance. Pingre subsequently confirmed this -suspicion 
 by a^ careful examination of the few trustworthy 
 records that could be collected from the writers of 
 that period. 
 
 From the earlier descriptions of this comet we 
 infer that its brilliancy is gradually diminishing. In 
 1456 its tail, which was slightly curved like a sword 
 or sabre, extended two-thirds of the distance from the 
 horizon to the zenith. The appearance of such an 
 object, in a grossly superstitious age, excited through- 
 out Europe the utmost consternation. The Moslems 
 had just taken Constantinople, and were threatening 
 
 * The Chinese, however, as appears from Blot's researches, had 
 observed the same fact 700 years earlier. See Humboldt's Cosmos, 
 vol. iv. (Bohn's ed.), p. 544. 
 
22 COMETS AND METEORS. 
 
 to advance westward into Europe. Pope Calix- 
 tus III., regarding the comet as confederate with 
 the Turk, ordered prayers to be offered three times 
 a day for deliverance from both. The alarm, how- 
 ever, was of short duration. Within ten days of its 
 appearance the comet reached its perihelion. Re- 
 ceding from the sun, the sword-like form began to 
 diminish in brilliancy and extent; and finally, to the 
 great relief of Europe, it entirely disappeared. 
 
 The perihelion passage of 1456 was, until recently, 
 the earliest known. It was shown by Laugier, how- 
 ever, in 1843, that among the notices of comets ex- 
 tracted by Edward Biot from the Chinese records, 
 were observations of a body in 1378, which was un- 
 doubtedly the comet of Halley. Further researches 
 among these annals enabled the same astronomer to 
 recognize two ancient returns, one in 760, the other 
 in 451. Still more recently the distinguished Eng- 
 lish astronomer, Mr. Hind, has traced back the re- 
 turns to the year 11 B.C. He remarks, however, 
 that previous to that epoch, "the Chinese descrip- 
 tions of comets are too vague to aid us in tracing 
 any more ancient appearances," and that " European 
 writers of these remote times render us no assist- 
 ance." Let us now inquire whether the comet had 
 probably made any former approach to the sun in 
 an orbit nearly identical with the present. It is 
 well known that the modern period of this body is 
 considerably less than the ancient. Thus, the mean 
 period since A.D. 1456 has been 75.88 years; while 
 from 11 B.C. to 1456 A.D. it was 77.27 years. In de- 
 termining the approximate . dates of former returns, 
 the ancient period should evidently be employed. 
 
HALLEY'S COMET. 23 
 
 , it is a remarkable fact that of more than 70 
 comets,* or objects supposed to be comets, whose 
 appearance was recorded during the six centuries 
 immediately preceding the year 11 B.C., but one 
 that of 166 B.C. was observed at a date correspond- 
 ing nearly to that of a former return of Halley's 
 comet. Of this object it is merely recorded that " a 
 torch was seen in the heavens." Whether this was 
 a comet or some other phenomenon, it is impossible 
 to determine. But as the comet of Halley was 
 more brilliant in ancient than in modern times, it 
 seems highly improbable that seven consecutive re- 
 turns of so conspicuous an object should have been 
 unrecorded, especially as twelve comets per century f 
 were observed during the same period. It would 
 appear, therefore, that the perihelion passage of 
 11 B.C. was in fact the first ever made by the comet, 
 or at least the first in an orbit nearly the same as 
 the present. 
 
 The motion of Halley's comet is retrograde. The 
 point of its nearest approach to the sun is situated 
 within the orbit of Yenus. Its greatest distance 
 from the centre of the system is nearly twice that 
 of Uranus, or 36 times that of the earth. The 
 comet is, consequently, subject to great changes of 
 temperature. When nearest the sun its light and 
 heat are, almost four times greater than the earth's; 
 when most remote, they are 1200 times less. In 
 the former position, the sun would appear much 
 larger than to us; in the latter, his apparent di- 
 
 * See the Catalogues of Chambers and Williams. 
 f The average number. 
 
24 COMETS AND METEORS. 
 
 ameter would not greatly exceed that of Jupiter, as 
 viewed from the earth. It would be difficult to con- 
 jecture what the consequences might be, were our 
 planet transported to either of these extremes of 
 the cometary path. In the perihelion, the waters 
 of the ocean would undoubtedly be reduced to a 
 state of vapor; in the aphelion, they would be 
 solidified by congelation. 
 
 II. Encke's Comet. 
 
 It was formerly supposed that all comets have 
 their aphelia far beyond the limits of the planetary 
 system. In 1818, however, a small comet was dis- 
 covered by Pons, the orbit of which was subse- 
 quently found to be wholly interior to that of Ju- 
 piter. Its elements were presented by Bouvard, in 
 1819, to the Board of Longitude at Paris. The 
 form and position of the orbit were immediately 
 found to correspond with those of a comet observed 
 by several astronomers in 1805. The different ap- 
 pearances were consequently regarded as returns of 
 the same body. Its elliptic orbit was calculated by 
 Encke, who found its period to be only about three 
 years and four months. Its perihelion is within the 
 orbit of Mercury; its aphelion, between the as- 
 teroids and the orbit of Jupiter. . 
 
 Encke's comet is invisible to the naked eye, ex- 
 cept in very favorable circumstances; it has no tail; 
 its motion, like that of the planets, is from west 
 to east; and its orbit is inclined about 13 to the 
 ecliptic. 
 
 A comparison of the successive periods of this 
 
BIELA'S COMET. 25 
 
 interesting object has led to the discovery that its 
 time of revolution is gradually diminishing; a fact 
 regarded by Encke and other astronomers as indi- 
 cating the existence of an ethereal medium. 
 
 Ill, Biela's Comet. 
 
 The discovery of Encke's comet of short period 
 was followed, in 1826, by that of another, whose 
 revolution is completed in about six years and eight 
 months. It was observed on the 27th of February, 
 by M. Biela, an Austrian officer; accordingly it 
 has since been known as Biela s comet. On com- 
 puting its elements and comparing them with those 
 of former comets, it was found to have been ob- 
 served in 1772 and 1805. Damoiseau having cal- 
 culated the dimensions of the comet's elliptic path 
 and the time of its return, announced as the result 
 of his computations the remarkable fact that the 
 orbits of the earth and cornet intersect each other, 
 and that the comet would cross the earth's path on 
 the 29th of October, 1832. This produced no little 
 alarm among the uneducated, especially in France. 
 Even some journalists are said to have predicted 
 the destruction of our globe by a collision with the 
 comet. When the latter, however, passed the point 
 of intersection at the predicted time, the earth was 
 at a distance of 50,000,000 miles. 
 
 At the return of 1845-6, Biela's comet exhibited 
 a most remarkable appearance. Instead of a single 
 comet, it appeared as two distinct bodies moving 
 together side by side, at a distance from each other 
 somewhat less than that of the moon from the earth. 
 
 3 
 
ZO COMETS AND METEORS. 
 
 Astronomers, anxious to determine whether the 
 eometary fragments had continued separate during 
 an entire revolution, awaited the next return with 
 no ordinary interest. The two bodies appeared at 
 the predicted time (September, 1852); their distance 
 apart having increased to 1,250,000 miles. In 1859 
 the comet, on account of its proximity to the sun, 
 entirely escaped detection. At the return in 1865-6 
 the position of the object was quite favorable for 
 observation, yet the search of astronomers was 
 again unsuccessful. In 1872 the body escaped de- 
 tection, both in Europe and America. One frag- 
 ment was seen, however, at Madras, India, on the 
 mornings of the 2d and 3d of December, several 
 weeks after its perihelion passage. The comet's 
 non-appearance in 1866 and its greatly diminished 
 magnitude in 1872 leave no room to doubt its pro- 
 gressive dissolution. This subject will again be re- 
 ferred to in discussing the phenomena of meteoric 
 showers. 
 
 IV. Faye's Comet. 
 
 On the 22d of November, 1843, M. Faye, of the 
 Paris Observatory, discovered a comet, which was 
 shown by Dr. Goldschmidt to revolve in an elliptic 
 orbit, the perihelion of which is exterior to the 
 orbit of Mars, and the aphelion immediately be- 
 yond that of Jupiter. The eccentricity is, therefore, 
 less than that of any other comet previously dis- 
 covered. Its period is about 7 years and 5 months. 
 
 It is possible that a comet moving in a parabola 
 or hyperbola, with the sun in the focus, may be 
 thrown into an elliptic orbit by the disturbing in- 
 
27 
 
 fluence of Jupiter or one of the other large planets. 
 The celebrated Leverrier undertook to determine 
 whether the comet of Faye had in this manner 
 been recently fixed as a permanent member of the 
 solar system. He found that it could not have been 
 so introduced since 1747, and, consequently, that it 
 must have completed at least thirteen revolutions 
 before its discovery. 
 
 This comet has been observed at each return 
 from 1843 to the present time. 
 
 V. De Vico's Comet. 
 
 On the 22d of August, 1844, De Vico, of Rome, 
 discovered a comet whose orbit is included between 
 those of the earth and Jupiter. Its period is 1996 
 days, or about 5J years. This body, from some 
 cause, perhaps a gradual dissolution, has not 
 been observed at any subsequent return. 
 
 VI. Brorsen's Comet. 
 
 On the 26th of February, 1846, Mr. Brorsen, of 
 Kiel, discovered a faint comet, the mean distance 
 and period of which are almost identical with those 
 of De Vico's. This comet was not observed during 
 the perihelion passage of 1851, on account of its 
 unfavorable position with respect to the sun. It 
 has, however, been subsequently detected. 
 
 VII. D'Arresf s Comet. 
 
 Dr. D'Arrest discovered a comet on the 27th of 
 June, 1851, which was soon found to move in an 
 
28 COMETS AND METEORS. 
 
 elliptic orbit, with a period of about 6J years. It 
 entirely escaped observation, both in Europe and 
 America, during its perihelion passage in 1857. It 
 was observed, however, at the Cape of Good Hope. 
 Its invisibility in 1864 was due to its unfavorable 
 position. At its return in 1870, it was first seen on 
 the 31st of August, by Dr. Winnecke, of Carlsruhe. 
 
 VIII. Turtle's Comet, 
 
 A faint telescopic comet was discovered at the 
 Observatory of Harvard College, on the evening of 
 January 4, 1858, by Mr. H. P. Tuttle. The same 
 body was independently found one week later by 
 Dr. Bruhns, of Berlin. From observations made 
 at Cambridge, Massachusetts, and Ann Arbor, 
 Michigan, its elements were soon computed by dif- 
 ferent astronomers; the result in each case coin- 
 ciding so closely with the elements of the second 
 comet of 1790, as to place its identity wholly beyond 
 doubt. Its period is nearly 13 years and 8 months. 
 It had returned, therefore, without detection, in the 
 years 1803, 1817, 1831, and 1844. On its approach 
 to perihelion in 1871, it was first detected by M. 
 Borelly, of Marseilles. 
 
 IX, Winnecke's Comet. 
 
 The second comet of 1858 was discovered on the 
 8th of March, by Dr. Winnecke, of Bonn. This 
 proved to be identical with the third comet of 1819, 
 whose period was computed by Encke to be about 
 5J years. It had therefore returned uuperceived 
 
29 
 
 no less than six times between 1819 and 1858. At 
 its return in 1863 it again escaped detection. The 
 perihelion passage of 1869 was made on the 30th of 
 June. The comet was seen as early as April 13, 
 and, after passing the sun, as late as October 11. 
 " Schonfeld states that in part of April and May it 
 appeared to have not one, but several, centres of 
 condensation, and Yogel says that, in the beginning 
 of June, ib had a much greater resemblance to a 
 star-cluster than to a nebula." This phenomenon, 
 it may be remarked, bore a striking resemblance to 
 the appearances observed in the comets of 389, 
 1618, and 1661. 
 
 X. Tempers Comet. 
 
 On the 19th of December, 1865, M. Tempel, of 
 Marseilles, discovered a small comet, which con- 
 tinued visible four weeks, passing its perihelion Jan- 
 uary 11, 1866. Dr. Oppolzer, of Vienna, after a 
 careful determination of its elements, announced 
 the interesting fact that its orbit very nearly inter- 
 sects those of the earth and Uranus; the perihelion 
 being situated immediately within the former, and 
 the aphelion a short distance exterior to the latter. 
 The period, according to the same astronomer, is 
 33 years and 65 days. The identity of this comet 
 with that of 1366 was suggested by Professor H. A. 
 Newton soon after its appearance, a suggestion 
 which subsequent research has strongly corrobo- 
 rated. It is also highly probable that the comet 
 observed in China, September 29, 1133, was a for- 
 mer return of the same body. In 1366 it was con- 
 
 3 
 
30 COMETS AND METEORS. 
 
 spicuous to the naked eye, while in 1866 it was 
 wholly invisible without a telescope, a fact indic- 
 ative of its gradual dissolution. The connection of 
 this comet with the meteors of November 14 will 
 be elsewhere considered. 
 
 XI. The Second Comet of 1867. 
 
 Another comet of short period was discovered by 
 M. Tempel on the 3d of April, 1867. Its orbit is 
 the least eccentric of all known comets: the peri- 
 helion being exterior to the orbit of Mars; the 
 aphelion interior to that of Jupiter. Its motion is 
 direct, and it completes a revolution in 5 years and 
 8 months. 
 
CHAPTER III. 
 
 COMETS WHOSE ELEMENTS INDICATE PERIODICITY, BUT 
 WHOSE RETURNS HAVE NOT BEEN RECOGNIZED. 
 
 I. The Group whose periods are nearly equal to that of 
 
 Uranus. 
 
 SINCE the commencement of the present century 
 five comets have been discovered, which form, with 
 Halley's, an interesting and remarkable group. 
 The first of these was detected by Pons, on the 20th 
 of July, 1812 ; the second by Olbers, on the 6th of 
 March, 1815; the third by De Yico, on the 28th of 
 February, 1846; the fourth by Brorsen, on the 20th 
 of July, 1847; and the last by Westphal, on the 
 27th of June, 1852. The periods of these bodies 
 are all nearly equal, ranging from 68 to 76 years; 
 their eccentricities are not greatly different ; the 
 motions of all, except that of Halley's, are direct ; 
 and the distances of their aphelia are somewhat 
 greater than Neptune's distance from the sun. Of 
 this group, the comets of 1812 and 1846 seem 
 worthy of special notice. The former became vis- 
 ible to the naked eye shortly after its discovery, and 
 each continued visible about ten weeks. Their 
 elements are as follows : 
 
 Perihelion Passage. 
 
 Long, of 
 Perih'n. 
 
 Long, of 
 A. Node. 
 
 Incl. 
 
 Peri'n 
 Dist. 
 
 Eccen- 
 tricity. 
 
 Pe- 
 riod. 
 
 Direc- 
 tion. 
 
 Com- 
 puter. 
 
 1812, Sept. 15d.7/i. 
 
 92 51' 
 
 253 33' 
 
 73 57' 
 
 0.7771 
 
 0.94454 
 
 70.68y 
 
 D 
 
 Encke. 
 
 1846, Mar. 5d.l2h. 
 
 90 31' 
 
 77 37' 
 
 85 6' 
 
 O.C637 
 
 0.96224 
 
 73.715 
 
 D 
 
 Peirce. 
 
32 
 
 COMETS AND METEORS. 
 
 The wonderful similarity of these elements, except 
 in the longitude of the ascending node, is at once 
 apparent. It will also be noticed that the longitude 
 of the descending node of the latter is very nearly 
 coincident with that of the ascending node of the 
 former. These remarkable coincidences are pre- 
 sented to the eye in the following diagram, where 
 
 Fig. 3. 
 
 the dotted ellipse represents the orbit of the comet 
 of 1812, and the continuous curve that of the comet 
 of 1846. 
 
COMETS WHOSE ELEMENTS INDICATE PERIODICITY. 33 
 
 It is infinitely improbable that these coincidences 
 should be accidental; they point undoubtedly to a 
 common origin of the two bodies. 
 
 According to the theory now generally accepted, 
 comets enter the solar system ab extra, move in 
 parabolas or hyperbolas around the sun, and, if un- 
 disturbed by the planets, pass off beyond the limits 
 of the sun's attraction, to be seen no more. If in 
 their motion, however, they approach very near any 
 of the larger planets, their direction is changed by 
 planetary perturbation, their orbits being some- 
 times transformed into ellipses. The new orbits of 
 such bodies would pass very nearly through the 
 points at which their greatest perturbation occurred ; 
 and accordingly we find that the aphelia of a large 
 proportion of the periodic comets are near the orbits 
 of the major planets. "I admit," says M. Hoek, 
 " that the orbits of comets are by nature parabolas 
 or hyperbolas, and that in the cases when elliptical 
 orbits are met with, these are occasioned by planet- 
 ary attractions, or derive their character from the 
 uncertainty of our observations. To allow the con- 
 trary would be to admit some comets as permanent 
 members of our planetary system, to which they 
 o ught to have belonged since its origin, and so to 
 assert the simultaneous birth of that system and of 
 these comets. As for me, I attribute to these a 
 primitive wandering character. Traveling through 
 space, they move from one star to another in order 
 to leave it again, provided they do not meet any 
 obstacle that may force them to remain in its 
 vicinity. Such an obstacle was Jupiter, in the 
 neighborhood of our sun, for the comets of Lexell 
 
34 COMETS AND METEORS. 
 
 and Brorsen, and probably for the greater part of 
 periodical comets ; the other part of which may be 
 indebted for their elliptical orbits to the attractions 
 of Saturn and the remaining planets. 
 
 " Generally, then, comets come to us from some 
 star or other. The attraction of our sun modifies 
 their orbit, as had been done already by each star 
 through whose sphere of attraction they had passed. 
 We can put the question if they come as single 
 bodies or united in systems." 
 
 The conclusion of this astronomer's interesting 
 discussion is that 
 
 " There are systems of comets in space that are broken 
 up by the attraction of our sun, and whose members attain, 
 as isolated bodies, the vicinity of the earth during a course 
 of several years."* 
 
 In the researches here referred to, it is shown by 
 Professor Hoek that the comets of 1860 III., 1863 L, 
 and 1863 IV. formed a group in space previous to 
 their entrance into our system. The same fact has 
 also been demonstrated in regard to other comets 
 which need not here be specified. Now, the comets 
 of 1812 and 1846 IV. have their aphelia near the 
 orbit of Neptune, and hence the original parabolas 
 in which they moved were probably transformed 
 into ellipses by the 'perturbations of that planet. 
 Before entering the solar domain, they were doubt- 
 less members of a cometary system. Passing 
 Neptune near the same time, and at some distance 
 from each other, their different relative positions 
 with regard to the disturbing body may account 
 
 * Monthly Notices of the K. A. S., vol. xxv., p. 243. 
 
COMETS OF THE JOVIAN GROUP. 35 
 
 for the slight differences in the elements of their 
 orbits. 
 
 Comets of the Jovian Group. 
 
 Besides the eight comets enumerated in Chapter 
 II. whose aphelia are in the vicinity of Jupiter's orbit, 
 five others have been observed which belong ap- 
 parently to the same cluster. These are the comets 
 of 1585, 1743 L, 1766 II., 1783, and 1819 IY. " The 
 fact that these comets have not been re-observed on 
 their successive returns through perihelion may be 
 explained either by the difficulty of observing them, 
 owing to their unfavorable positions, and to the 
 circumstances of observers not expecting their re- 
 appearance, their periodic character not being then 
 suspected, or because they may have been thrown 
 by the disturbing action of the larger planets into 
 orbits such as to keep them continually out of the 
 range of view of terrestrial observers."* 
 
 LexelPs comet of 1770 is the most remarkable 
 instance known of the change produced in the 
 orbits of these bodies by planetary attraction. This 
 comet passed so near Jupiter in 1779 that the attrac- 
 tion of the latter was 200 times greater than that of 
 the sun. The consequence was that the comet, 
 whose mean distance corresponded to a period of 
 5 J years, was thrown into an orbit so entirely differ- 
 ent that it has never since been visible. 
 
 * Dr. Lardner. 
 
36 COMETS AND METEORS. ' 
 
 PETERS' COMET. 
 
 A telescopic comet was discovered by Dr. Peters 
 on the 26th of June, 1846, which continued to be 
 observed till the 21st of July. Its period, according 
 to the discoverer, is about 13 years, and its aphelion, 
 like that of Tuttle's comet, is in the vicinity of 
 Saturn's orbit. It was expected to return in 1859, 
 and again in 1872, but each time escaped detection, 
 owing probably to the fact that its position was un- 
 favorable for observation. 
 
 STEPHAN'S COMET (1867 L). 
 
 In January, 1867, M. Stephan, of Marseilles, dis- 
 covered a new comet, the elements of which, after 
 two months' observations, were computed by Mr. 
 G. M. Searle, of Cambridge, Massachusetts. The 
 perihelion of this body is near the orbit of Mars ; its 
 aphelion near that of Uranus, the least distance of 
 the orbits being about 2,000,000 miles. The present 
 form of the cometary path is doubtless due to the 
 disturbing action of Uranus. The comet completes 
 its revolution in 33.62 years; consequently (as has 
 been pointed out by Mr. J. R. Hind) five of its 
 periods are almost exactly equal to two periods of 
 Uranus. The next approximate appulse of the two 
 bodies will occur in 1985, when the form of the 
 comet's orbit may be sensibly modified. 
 
 ELLIPTIC COMETS WHOSE APHELIA ARE AT A MUCH 
 GREATER DISTANCE THAN NEPTUNE'S ORBIT. 
 
 In October, 1097, a comet was seen both in Eu- 
 rope and China, which was noted for the fact of its 
 
THE GREAT COMET OF 1858. 37 
 
 having two' distinct tails, making with each other 
 an angle of about 40. From a discussion of the 
 Chinese observations (which extended through a 
 longer period than the European), Laugier con- 
 cluded that this body is identical with the third 
 comet of 1840, which was discovered by G-alle on 
 the 6th of March. If, therefore, it has made no 
 intermediate return without being observed, it must 
 have a period of about 743 years. Jt is also highly 
 probable, from the similarity of elements, that the 
 comet which passed its perihelion on the 5th of June, 
 1845, was a reappearance of the comet of 1596, the 
 period of revolution being 249 years. The elements 
 of the great comet of 1843 are somewhat uncertain. 
 There is a probability, however, of the identity of 
 this body with the comet of 1668. This would make 
 the period 175 years. The third comet of 1862 is 
 especially interesting from its connection with the 
 August meteors. Its period, according to Dr. Op- 
 polzer, is 121J years. 
 
 THE GREAT COMET OF 1858 
 
 was one of the most remarkable in the nineteenth 
 century. It was discovered on the 2d,of June, by 
 Donati, of Florence, and first became visible to the 
 naked eye about the last of August. The comet 
 attained its greatest brilliancy about the 10th of 
 October, when its distance from the earth was 
 50,000,000 miles. The length of its tail somewhat 
 exceeded this distance. If, therefore, the comet had 
 been at that time directly between the sun and the 
 
 4 
 
38 COMETS AND METEORS. 
 
 earth, the latter must have been enveloped for a 
 number of hours in the cometic matter. 
 
 The observations of this comet during a period of 
 five months enabled astronomers to determine the 
 elements of its orbit within small limits of error. It 
 completes a revolution, according to Newcomb, in 
 1854 years, in an orbit somewhat more eccentric 
 than that of Halley's comet. It will not return 
 before the 38th. century, and will only reach its 
 aphelion about the year 2800. Its motion per second 
 when nearest the sun is 36 miles; when most remote, 
 only 234 yards. 
 
CHAPTEK IV. 
 
 OTHER REMARKABLE COMETS. 
 
 IT remains to describe some of the most remark- 
 able comets of which we have any record, but of 
 which we have no means of determining with cer- 
 tainty whether they move in ellipses, parabolas, or 
 hyperbolas. 
 
 In the year 466 B.C., a large comet appeared sim- 
 ultaneously with the famous fall of meteoric stones 
 near ^Egospotamos. The former was supposed 
 by the ancients to have had some agency in pro- 
 ducing the latter phenomenon. Another of extra- 
 ordinary magnitude appeared in the year 373 B.C. 
 This comet was so bright as to throw shadows, and 
 its tail extended one-third of the distance from the 
 horizon to the zenith. The years 156, 136, 130, and 
 48, before our era, were also signalized by the ap- 
 pearance of very large comets. The apparent mag- 
 nitude of the first of these is said to have equaled 
 that of the sun itself; while its light was sufficient 
 to diminish sensibly the darkness of the night. 
 The second is said to have filled a fourth part of 
 the celestial hemisphere. The comet of 130 B.C., 
 sometimes called the comet of Mithridates, because 
 of its appearance about the time of his birth, is said 
 to have rivaled the sun in splendor. 
 
 In A.D. 178 a large comet was visible during a 
 
 39 
 
40 COMETS AND METEORS. 
 
 period of nearly three months. Its nucleus had a 
 remarkably red or fiery appearance, and the great- 
 est length of its tail exceeded 60. The most bril- 
 liant comets of the sixth century were probably 
 those of 531 and 582. The train of the latter, as 
 seen in the west soon after sunset, presented the 
 appearance of a distant conflagration. 
 
 Great comets appeared in the years 975, 1264, 
 and 1556. Of these, the comet of 1264 had the 
 greatest apparent magnitude. It was first seen 
 early in July, and attained its greatest brilliancy in 
 the latter part of August, w r hen its tail was 100 in 
 length. It disappeared on the 3d of October, about 
 the time of the death of Pope Urban IV., of which 
 event the comet, in consequence of this coincidence, 
 was considered the precursor. These comets, on 
 account of the similarity of their elements, were 
 believed by many astronomers to be the same, and 
 to have a period of about 300 years. In the case of 
 identity, however, another reappearance should 
 have occurred soon after the middle of the nineteenth 
 century. As no such return was observed, we may 
 conclude that the comets were not the same, and 
 that their periods are wholly unknown. 
 
 The comet discovered on the 10th of November, 
 
 1618, was one of the largest in modern times; its 
 tail having attained the extraordinary length of 
 104. The comet of 1652, so carefully observed by 
 Hevelins, almost equaled the moon in apparent 
 magnitude. It shone, however, with a lurid, dismal 
 light. The tail of the comet of 1680 was 90 in 
 length. This body is also remarkable for its near 
 
 approach to the sun ; its least distance from the 
 
OTHER REMARKABLE COMETS. 41 
 
 solar surface having been only 147,000 miles. It 
 will always be especially memorable, however, for 
 having furnished Newton the data by means of 
 which he first showed that comets in their orbital 
 motions are governed by the same principle that 
 regulates the planetary revolutions. 
 
 Of all the comets which appeared during the eight- 
 eenth century, that which passed its perihelion on the 
 7th of October, 1769, had the greatest apparent mag- 
 nitude. It was discovered by Messier on the 8th of 
 August, and continued to be observed till the 1st of 
 December. On the llth of September the length 
 of its tail was 97. The comet discovered on the 
 26th of March, 1811, is in some respects the most 
 remarkable on record. It was observed during a 
 period of 16 months and 22 days, the longest 
 period of visibility known. On account of its situ- 
 ation with respect to the earth, the apparent length 
 of its tail was much less than that of some other 
 cornets ; its true length, however, was at one time 
 120,000,000 miles; and Sir William Herschel found 
 that on the 12th of October the greatest circular 
 section of the tail was 15,000,000 miles in diameter. 
 The same astronomer found the diameter of the 
 head of the comet to be 127,000 miles, and that of 
 the envelope at least 643,000. As a general thing, 
 the length of. a comet-train increases very rapidly 
 as the body approaches the sun. But the perihelion 
 distance of the comet of 1811 was considerably 
 greater than the distance of the earth from the 
 sun ; while its nearest approach to the earth was 
 110,000,000 miles. Its true magnitude, therefore, 
 
 has probably not been surpassed by any other ob- 
 
 4* 
 
42 COMETS AND METEORS. 
 
 served ; and had its perihelion been very near the 
 sun, it must have exhibited an appearance of terrific 
 grandeur. This comet has an elliptic orbit, and its 
 period, according to Argelander, is 3065 years. 
 
 The great comet of 1861 was discovered on the 
 13th of May, by Mr. John Tebbut/Jr., of New 
 South Wales. In this country, as well as in Eu- 
 rope, it was first generally observed on the evening 
 of June 30, 19 days after its perihelion passage. 
 Sir John Herschel, who observed it in Kent, Eng- 
 land, remarks that it far exceeded in brilliancy any 
 comets he had ever seen, not excepting those of 
 1811 and 1858. According to Father Secchi, of the 
 Collegio Romano, the length of its tail was 118. 
 This, with a single exception,* is the greatest on 
 record. The computed orbit is elliptical ; the 
 period, 419 years. 
 
 * The tail of the first comet of 1865 (observed in the Southern 
 Hemisphere) attained the unprecedented length of 150. M. N. 
 R. A. S., vol. xxv., p. 220. 
 
CHAPTEE Y. 
 
 THE POSITION AND ARRANGEMENT OF COMETARY ORBITS. 
 
 THE cosmical masses from which comets are de- 
 rived seem to traverse in great numbers the inter- 
 stellar spaces. In consequence of the sun's pro- 
 gressive motion, these nebulous bodies are some- 
 times drawn toward the centre of our system. If, 
 in this approach, they are not disturbed by any of 
 the large planets, they again recede in parabolas or 
 hyperbolas. When, however, as must sometimes 
 be the case, they pass near Jupiter, Saturn, Uranus, 
 or Neptune, their orbits may be transformed into 
 elongated ellipses. The periodicity of many comets 
 may thus be accounted for. 
 
 In the present chapter it is proposed to consider 
 the probable consequences of the sun's motion 
 through regions of space in which cometary matter 
 is widely diffused ; to compare our theoretical de- 
 ductions with observed phenomena; and thus refer 
 to their physical cause a variety of facts which have 
 hitherto received no satisfactory explanation.* 
 
 1. As comets, at least in many instances, owe 
 their periodicity to the disturbing action of the 
 major planets, and as this planetary influence is 
 
 * This chapter is the substance of a paper read before the 
 American Philosophical Society, November 19, 1869. 
 
 43 
 
44 COMETS AND METEORS. 
 
 sometimes sufficient, especially in the case of Ju- 
 piter and Saturn, to change the direction of cometary 
 motion, the great majority of periodic comets should 
 move in the same direction with the planets. Now, 
 of the comets known to be elliptical, 70 per cent. 
 have direct motion. In this respect, therefore, theory 
 and observation are in striking harmony. 
 
 2. When the relative positions of a comet and 
 the disturbing planet are such as to give the trans- 
 formed orbit of the former a small perihelion dis- 
 tance, the comet must return to the point at which 
 it received its greatest perturbation ; in other words, 
 to the orbit of the planet. The aphelia of the comets 
 of short period ought therefore to be found, for the 
 most part, in the vicinity of the orbits of the major planets. 
 This, as already shown in Chapters II. and III., is 
 strikingly the case. The actual distances of these 
 aphelia, however, as compared with the respective 
 distances of Jupiter, Saturn, Uranus and Neptune, 
 are presented at one view in the following tables : 
 
 I. COMETS WHOSE APHELION DISTANCES ARE NEARLY EQUAL TO 
 5.20, THE RADIUS OF JUPITER'S ORBIT. 
 
 Comets. Aph. Dist. 
 
 1. Encke's 4.09 
 
 2. 1819 IV 4.81 
 
 3. De Vico's 5 02 
 
 4. Pigott's (1783) 5.28 
 
 5. 1867 II 5.29 
 
 6. 1743 1 5.32 
 
 7. 1766 II 5.47 
 
 8. 1819 III 5.55 
 
 9. Brorsen's 5.64 
 
 10. D'Arrest's 5.75 
 
 11. Paye's 5.93 
 
 12. Biela's... .. 6.19 
 
POSITION, ETC., OF COMETAKY ORBITS. 45 
 
 II. COMETS WHOSE APHELION DISTANCES ARE NEARLY EQUAL 
 
 TO 9.54, THE KADIUS OF SATURN'S ORBIT. 
 
 Comets. Aph-. Dist. 
 
 1. Peters' (1846 VI.) 9.45 
 
 2. Tattle's (1858 I.) 10.42 
 
 III. COMETS WHOSE APHELION DISTANCES ARE NEARLY EQUAL 
 
 TO 19.18, THE KADIUS OF URANUS'S ORBIT. 
 
 Comets. Aph. Dist. 
 
 1. 1867 1 19.28 
 
 2. November meteors 19.65 
 
 3. 1866 1 19.92 
 
 IV. COMETS WHOSE APHELION DISTANCES ARE NEARLY EQUAL 
 
 TO 30.04, THE RADIUS OF NEPTUNE'S ORBIT. 
 
 Comets. Aph. Dist. 
 
 1. Westphal's (1852 IV.) 31.97 
 
 2. Pons' (1812) 33.41 
 
 3. Gibers' (1815) 34.05 
 
 4. De Vice's (1846 IV.) 34.35 
 
 5. Brorsen's (1847V.) 35.07 
 
 6. Halley's * 35.37 
 
 The coincidences here pointed out (some of which 
 have been noticed by others) appear, then, to be 
 necessary consequences of the motion of the solar 
 system through spaces occupied by meteoric nebulae. 
 Hence the observed facts receive an obvious expla- 
 nation. 
 
 In regard to comets of long period we have only 
 to remark that, for anything we know to the con- 
 trary, there may be causes of perturbation far ex- 
 terior to the orbit of Neptune. 
 
 3. From what we observe in regard to the larger 
 bodies of the universe a clustering tendency being 
 
 * Halley's comet in aphelio is too remote from the plane of the 
 ecliptic to be much disturbed by Neptune. Has the original 
 position of the orbit been changed by Jupiter's influence? 
 
46 COMETS AND METEORS. 
 
 everywhere apparent, it seems highly improbable 
 that cometic matter should be uniformly distributed 
 in the sidereal spaces. We would expect, on the 
 contrary, to find it collected in groups or clusters. 
 This view is also in remarkable harmony with the 
 facts of observation. In 150 years, from 1600 to 
 1750, 16 comets were visible to the naked eye; of 
 which 8 appeared in the 25 years from 1664 to 1689. 
 Again, during 60 years, from 1750 to 1810, only 5 
 comets were visible to the naked eye, while in 
 the next 50 years there were double that num- 
 ber. The probable cause of such variations is suf- 
 ficiently obvious. As the sun in its progressive 
 motion approaches a cometary group, the latter is 
 drawn toward the centre of our system ; the nearer 
 members with greater velocity than the more re- 
 mote. Those of the same cluster would enter the 
 solar domain at periods not very distant from each 
 other ; the forms of their orbits depending upon 
 their original relative positions with reference to 
 the sun's course, and also on planetary perturba- 
 tions. It is evident also that the passage of the 
 solar system through a region of space compara- 
 tively destitute of cometic clusters would be indi- 
 cated by a corresponding paucity of comets. 
 
 4. The line of apsides of a large proportion of 
 comets will be approximately coincident with the 
 solar orbit. The point towards which the sun is 
 moving is in longitude about 260. The quadrants 
 bisected by this point and that directly opposite 
 extend from 215 to 305, and from 35 to 125. 
 The number of cometary perihelia found in these 
 quadrants up to July, 1868 (periodic comets being 
 
POSITION, ETC., OP COMETARY ORBITS. 47 
 
 counted but once) was 159, or 62 per cent. ; in the 
 other two quadrants, 98, or 38 per cent. 
 
 This tendency of the perihelia to crowd together 
 in two opposite regions has been noticed by different 
 writers. 
 
 5. Comets whose positions before entering our 
 system were very remote from the solar orbit must 
 have overtaken the sun in its progressive motion; 
 hence their perihelia must fall, for the most part, in' 
 the vicinity of,the point towards which the sun is 
 moving; and they must in general have very small 
 perihelion distances. Now, what are the observed 
 facts in regard to the longitudes of the perihelia of 
 the comets which have approached within the least 
 distance of the sun's surface? But three have had a 
 perihelion distance less than 0.01. All these, it will 
 be seen by the following table, have their perihelia 
 in close proximity to the point referred to: 
 
 I. COMETS WHOSE PERIHELION DISTANCES ARE LESS THAN 0.01. 
 
 Perihelion Passage. Per. Dist. Long, of Per. 
 
 1. 1668, Feb ................ 28rf.'l3A. 0.0047 277 2' 
 
 2. 1680, Dec ................ 17 23 00062 262 49 
 
 3. 1843, Feb ................ 27 9 0.0055 278 39 
 
 In Table II. all but the last have their perihelia in 
 the same quadrant. 
 
 II. COMETS WHOSE PERIHELION DISTANCES ARE GREATER THAN 
 
 0.01 AND LESS THAN 0.05. 
 
 Perihelion Passage. 
 1 1689 Nov 29<2 
 
 4h 
 
 Per. Dist. 
 0189 
 
 Long, of Per. 
 269 41' 
 
 2 1816 March 1 
 
 8 
 
 0485 
 
 267 35 
 
 3 1826 Nov 18 
 
 9 
 
 00268 
 
 315 31 
 
 4 1847 March . 30 
 
 6 
 
 0425 
 
 276 2 
 
 5. 1865, Jan... ...14 
 
 7 
 
 0.0260 
 
 141 15 
 
 The perihelion of the first comet in Table III. is 
 
48 COMETS AND METEORS. 
 
 remote from the direction of the sun's motion; that 
 of the second is distant but 14, and ofvthe third 
 21. 
 
 III. COMETS WHOSE PERIHELION DISTANCES ABE GREATER 
 
 THAN 0.05 AND LESS THAN 0.1. 
 
 Perihelion Passage. Per. Dist. Long, of Per. 
 
 1. 1593, July ISd. 13A. 0.0891 176 19' 
 
 2. 1780, Sept 30 22 0.0963 246 35 
 
 3. 1821, March 21 12 0.0918 239 29 
 
 With greater perihelion distances the tendency of 
 the perihelia to crowd together round the point indi- 
 cated is less distinctly marked. 
 
 6. Few comets of small perihelion distance should 
 have their perihelia in the vicinity of longitude 80, 
 the point opposite that towards which the sun is 
 moving. Accordingly we find, by examining a 
 table of cometary elements, that with a perihelion 
 distance less than 0.1 there is not a single perihelion 
 between 35 and 125; between 0.1 and 0.2 but 3; 
 and between 0.2 and 0.3 only 1. 
 
CHAPTER VI. 
 
 THE DISINTEGRATION OF COMETS. 
 
 THE fact that in several instances meteoric streams 
 move in orbits identical with those of certain comets 
 was first established by the researches of Signor 
 Schiaparelli. The theory, however, of an intimate 
 relationship between comets and meteors was advo- 
 cated by the writer as long since as 1861,*- several 
 years previous to the publication of Schiaparelli's 
 memoirs. In the essay here referred to it was 
 maintained 
 
 1. That meteors and meteoric rings u are the debris 
 of ancient but now disintegrated comets whose mat- 
 ter has become distributed around their orbits." 
 
 2. That the separation of Biela's comet as it ap- 
 proached the sun in December, 1845, was but one 
 in a series of similar processes which would proba- 
 bly continue until the individual fragments would 
 become invisible. 
 
 3. That certain luminous meteors have entered 
 the solar system from the interstellar spaces. f 
 
 4 That the orbits of some meteors and periodic 
 comets have been transformed into ellipses by plan- 
 etary perturbation ; and 
 
 * Danville Quarterly Review, December, 1861. 
 f Others, it was supposed, might have originated within the 
 system, a view which the writer has not wholly abandoned. 
 
 5 49 
 
50 COMETS AND METEORS. 
 
 5. That numerous facts some observed in ancient 
 and some in modern times have been decidedly 
 indicative of cometary disintegration. 
 
 What was thus proposed as theory has been since 
 confirmed as undoubted facts. When the hypothe- 
 sis was originally advanced, the data required for 
 its mathematical demonstration were entirely want- 
 ing. The evidence, however, by which it was sus- 
 tained was sufficient to give it a high degree of 
 probability. 
 
 The existence of a divellent force by which comets 
 near their perihelia have been separated into parts 
 is clearly shown by the following facts. Whether 
 this force, as suggested by Schiaparelli, is simply the 
 unequal attraction of the sun on different parts of 
 the nebulous mass, or whether, in accordance with 
 the views of other astronomers, it is to be regarded 
 as a cosrnical force of repulsion, is a question left for 
 future discussion. 
 
 HISTORICAL FACTS. 
 
 1. Seneca informs us that Ephoras, a Greek writer 
 of the fourth century before Christ had recorded the 
 singular fact of a comet's separation into two distinct 
 parts.* This statement was deemed incredible by 
 the Roman philosopher, inasmuch as the occurrence 
 was then without a parallel. More recent observa- 
 tions of similar phenomena leave no room to ques- 
 tion the historian's veracity. 
 
 2. The head of the great comet of A.D. 389, ac- 
 
 * " Quaest. Nut.," lib. vii., cap. xvi. 
 
HISTORICAL FACTS. 51 
 
 cording to the writers of that period, was " composed 
 of several small stars." (Hind's "Comets," p. 103.) 
 
 3. On Jane 27, A.D. 416, two comets appeared in 
 the constellation Hercules, and pursued nearly the 
 same apparent path. Probably at a former epoch 
 the pair had constituted a single comet.* 
 
 4. On August 4, 813, "a comet was seen which 
 resembled two moons joined together." They sub- 
 sequently separated, the fragments assuming differ- 
 ent forms, f 
 
 5. The Chinese annals record the appearance of 
 three comets one large and two smaller ones at 
 the same time, in the year 896 of our era. " They 
 traveled together for three days. The little ones 
 disappeared first, and then the large one."J The 
 bodies were probably fragments of a large comet 
 which, on approaching the sun, had been separated 
 into parts a short time previous to the date of their 
 discovery. 
 
 6. The third comet of 1618. The great comet of 
 1618 exhibited decided symptoms of disintegration. 
 When first observed (on November 30), its appear- 
 ance was that of a lucid and nearly spherical mass. 
 On the eighth day the process of division was dis- 
 tinctly noticed, and on the 20th of December it 
 resembled a cluster of small stars. 
 
 7. The comet 0/1661. The elements of the comets 
 of 1532 and 1661 have a remarkable resemblance, 
 
 * Chambers' " Descr. Astr.," p. 374. 
 f Ibid., p. 383. 
 % Ibid., p. 388. 
 
 g Hevelius, "Cometographia," p. 341. See also Grant's "Hist, 
 of Phys. Astr.," p. 302. 
 
52 COMETS AND METEORS. 
 
 and previous to the year 1790 astronomers regarded 
 the bodies as identical. The similarity of the ele- 
 ments is seen at a glance in the following table: 
 
 Comet of 1532. Comet of 1661. 
 
 Longitude of perihelion 111 48' 115 16' 
 
 Longitude of ascending node 87 23 81 54 
 
 Inclination 32 36 33 I 
 
 Perihelion distance 0.5192 0.4427 
 
 Motion Direct. Direct. 
 
 The elements of the former are by Gibers; those 
 of the letter by Mechain. The return of the comet 
 about 1790, though generally expected, was looked 
 for in vain. As a possible explanation of this fact, 
 it is interesting to recur to an almost forgotten state- 
 ment of Hevelius. This astronomer observed in the 
 comet of 1661 an apparent breaking up of the body 
 into separate fragments.* The case may be analo- 
 gous to that of Biela's comet. 
 
 8. The identity of the comets of 1866 and 1366, 
 first suggested by Professor H. A. Newton, is now 
 unquestioned. The existence then of a meteoric 
 swarm, moving in the same track, is not the only 
 evidence of the original comet's partial dissolution. 
 The comet of 1866 was invisible to the naked eye ; 
 that of 1366, seen under nearly similar circum- 
 stances, was a conspicuous object. The statement 
 of the Chinese historian that " it appeared nearly as 
 large as a tow measure, "f though somewhat indefi- 
 nite, certainly justifies the conclusion that its magni- 
 tude has greatly diminished during the last 500 
 years. The meteors moving in the same orbit are 
 doubtless the products of this gradual separation. 
 
 * "Cometographia," p. 417. 
 f Williams' " Chinese Observations of Comets," p. 73. 
 
HISTORICAL FACTS. 53 
 
 9. The bipartition of Biela's comet in 1845, as 
 well as the non-appearance of the two fragments in 
 1865 and 1872,* were referred to in a previous 
 chapter. 
 
 The comet of Halley, if we may credit the descrip- 
 tions given by ancient writers, has been decreasing 
 in brilliancy from age to age. The same is true in 
 regard to several others believed to be periodic. The 
 comet of A.D. 1097 had a tail 50 long! At its return, 
 in March, 1840, the length of its tail was only 5. 
 The third comet of 1790 and the first of 1825 are 
 supposed, from the similarity of their elements, 
 to be identical. Each perihelion passage occurred 
 in May, yet the tail at the former appearance wa'k 
 4 in length, at the latter but 2J. Other instances 
 might be specified of this apparent gradual disso- 
 lution. It would seem, indeed, extremely improb- 
 able that the particles driven off from comets in 
 their approach to the sun, forming tails extending 
 millions of miles from the principal mass, should 
 again be collected around the same nuclei. 
 
 The fact, then, that meteors move in the same 
 orbits with comets is but a consequence of that dis- 
 ruptive process so clearly indicated by the phe- 
 nomena described. In this view of the subject, 
 comets even such as move in elliptic orbits are 
 not to be regarded as permanent members of the 
 solar system. Their debris becomes gradually scat- 
 tered around the orbit. Some parts of the nebulous 
 ring will be more disturbed than others by planet- 
 
 * One of the parts was seen at Madras, India, on the mornings 
 of December 2 and 3, 1872. 
 
 5* 
 
54 COMETS AND METEOKS. 
 
 ary perturbation. Portions of such streams as 
 nearly intersect the earth's path sometimes pene- 
 trate the atmosphere. Their rapid motion renders 
 them luminous. If very minute, they are burnt up 
 or dissipated without leaving any solid deposit; we 
 then have the phenomena of shooting-stars. "When, 
 however, as is sometimes the case, they contain a 
 considerable quantity of solid matter, they reach 
 the earth's surface as meteoric stones. 
 
II. 
 
 METEORS 
 
CHAPTER VII. 
 
 METEORIC STONES. 
 
 ALTHOUGH numerous instances of the fall of aero- 
 lites had been recorded, some of them apparently 
 well authenticated, the occurrence long appeared 
 too marvelous and improbable to gain credence 
 with scientific men. Such a shower of rocky frag- 
 ments occurred, however, on the 26th of April, 
 1803, at L'Aigle, in France, as forever to dissipate 
 all doubt on the subject. Similar displays since 
 that time have been frequently witnessed; indeed 
 scarcely a year passes without the fall of meteoric 
 stones in some part of the earth, either singly or in 
 clusters. It would not comport with the design of 
 the present treatise to give an extended list of these 
 phenomena. The following account, however, in- 
 cludes the most important instances in which the 
 fall of meteoric stones has been actually observed : 
 
 (1.) 1478 B.C. According to the celebrated Pa- 
 rian chronicle, an aerolite, or thunder-stone, as it 
 was called, fell in the island of Crete, about 1478 
 years before the Christian era. This is undoubt- 
 edly the most ancient stone-fall on record. Mete- 
 oric masses have been found, however, the fall of 
 which probably occurred at an epoch still more 
 ancient. 
 
 (2.) 1200 B.C. A number of stones, which were 
 
 5T 
 
58 COMETS AND METEORS. 
 
 anciently preserved in Orchomenos, a town of 
 Boeotia, were said to have fallen from heaven about 
 twelve centuries before our era. 
 
 (3.) 1168 B.C. A mass of iron, as we learn from 
 the Parian chronicle, was seen to descend upon 
 Mount Ida, in Crete. 
 
 (4.) 654 B.C. According to Livy, a number of 
 meteoric stones fell on the Albau Hill, near Rome, 
 about the year 654 B.C. 
 
 (5.) 616 B.C., January 14. It is related in the 
 Chinese annals that on the 14th of January, 616 
 B.C., a meteoric stone-fall broke several chariots and 
 killed ten men. 
 
 (6.) 466 B.C. A mass of rock, described as " of 
 the size of two millstones," fell at ^Egospotamos, 
 in Thrace. An attempt to rediscover this meteoric 
 mass, so celebrated in antiquity, was recently made, 
 but without success. Notwithstanding this failure, 
 Humboldt expressed the hope that, as such a body 
 would be difficult to destroy, it may yet be found, 
 " since the region in which it fell is now become so 
 easy of access to European travelers." 
 
 (7.) 465 B.C. The famous stone called the " Mo- 
 ther of the Gods," and which is described or alluded 
 to by many ancient writers, was said to have fallen 
 from the skies. The poet Pindar was seated on a 
 hill at the time of its descent, and the meteorite 
 struck the earth near his feet. The stone, as it fell, 
 was encircled by fire. "It is said to have been of 
 moderate dimensions, of a black hue, of an irregu- 
 lar, angular shape, and of a metallic aspect. An 
 oracle had predicted that the Romans would con- 
 tinue to increase in prosperity if they were put 
 
METEORIC STONES. 59 
 
 in possession of this precious deposit ; and Publius 
 Scipio Nasico was accordingly deputed to Attalus, 
 King of Pergamus, to obtain and receive the sacred 
 idol, whose worship was instituted at Rome 204 
 years before the Christian era." Edinburgh Ency- 
 clopedia. 
 
 (8.) A.D. 921. An immense aerolite fell into the 
 river (a branch of the Tiber) at Kami, in Italy. It 
 projected three or four feet above the surface of the 
 water. 
 
 (9.) 1492, November 1. An aerolite, weighing 
 276 pounds, fell at Ensisheirn, in Alsace, penetra- 
 ting the earth to the depth of three feet. This 
 stone, or the greater part of it, may still be seen at 
 Ensisheim. 
 
 (10.) 1511, September 14. At noon an almost 
 total darkening of the heavens occurred at Crema. 
 /'During this midnight gloom," says a writer of 
 that period, " unheard-of thunders, mingled with 
 awful lightnings, resounded through the heavens. 
 . On the plain of Crerna, where never before 
 was seen a stone the size of an egg, there fell 
 pieces of rock of enormous dimensions and of im- 
 mense weight. It is said that ten of these were 
 found, weighing 100 pounds each." A monk was 
 struck dead at Crema by one of these rocky frag- 
 ments. This terrific display is said to have lasted 
 two hours, and 1200 aerolites were subsequently 
 found. 
 
 (11.) 1637, November 29. A stone, weighing 54 
 pounds, fell on Mount Vaison, in Provence. 
 
 (12.) 1650, March 30. A Franciscan monk was 
 killed at Milan by the fall of a meteoric stone. 
 
60 COMETS AND METEORS. 
 
 (13.) 1674. Two Swedish sailors were killed on 
 shipboard by the fall of an aerolite. 
 
 (14.) 1751, May 26. Two meteoric masses, con- 
 sisting almost wholly of iron, fell near Agram, the 
 capital of Croatia. The larger fragment, which 
 weighs 72 pounds, is now in Vienna. 
 
 (15.) 1790, July 24. Between 9 and 10 o'clock 
 at night a very large meteor was seen near Bor- 
 deaux, France. Over Barbotan a loud explosion 
 was heard, which was followed by a shower of me- 
 teoric stones of various magnitudes. 
 
 (16.) 1794, July. A fall of about a dozen aero- 
 lites occurred at Sienna, Tuscany. 
 
 (17.) 1795, December 13. A large meteoric 
 stone fell near Wold Cottage, in Yorkshire, Eng- 
 land. " Several persons heard the report of an ex- 
 plosion in the air, followed by a hissing sound ; and 
 afterward felt a shock, as if a heavy body had fallen, 
 to the ground at a little distance from them. One 
 of these, a plowman, saw a huge stone falling to- 
 ward the earth, eight or nine yards from the place 
 where he stood. It threw up the mould on every 
 side ; and after penetrating through the soil, lodged 
 some inches deep in solid chalk-rock. Upon being 
 raised, the stone was found to weigh 56 pounds. It 
 fell in the afternoon of a mild, but hazy day, during 
 which there was no thunder or lightning; and the 
 noise of the explosion was heard through a consid- 
 erable district." Milners Gallery of Nature, p. 134. 
 
 (18.) 1796, February 19. A stone of 10 pounds' 
 weight fell in Portugal. 
 
 (19.) 1803, April 26. This remarkable shower 
 was referred to on a previous page. At 1 o'clock 
 
METEORIC STONES. 61 
 
 P.M., the heavens being almost cloudless, a tremen- 
 dous noise, like that of thunder, was heard, and at 
 the same time an immense fire-ball was seen mov- 
 ing with great rapidity through the atmosphere. 
 This was followed by a violent explosion, which 
 lasted several minutes, and which was heard not 
 only at L'Aigle, but in every direction around it to 
 the distance of 70 miles. Immediately after, a great 
 number of meteoric stones fell to the earth, gene- 
 rally penetrating to some distance beneath the sur- 
 face. Nearly 3000 of these fragments were found 
 and collected, the largest weighing about 17 pounds. 
 The occurrence very naturally excited great atten- 
 tion. M. Biot, under the authority of the govern- 
 ment, repaired to the place, collected the various 
 facts in regard to the phenomenon, took the testi- 
 mony of witnesses, etc., and finally embraced the 
 results of his investigations in an elaborate memoir. 
 (20.) 1807, December 14. A large meteor ex- 
 ploded over Weston, Connecticut. The height, di- 
 rection, velocity and magnitude of this body were 
 discussed by Dr. Bowditch in a memoir commu- 
 nicated to the American Academy of Arts and 
 Sciences in 1815. The appearance of the meteor 
 occurred about 6h. 15m. A.M., -just after daybreak. 
 Its apparent diameter was half that of the full 
 moon; its time of flight, about 30 seconds. Within 
 less than a minute from the time of its disappear- 
 ance three distinct reports, like those of artillery, 
 were heard over an area several miles in diameter. 
 Each explosion was followed by the fall of meteoric 
 stones. Unlike most aerolites, these bodies when 
 first found were so soft as to be easily pulverized 
 
62 COMETS AND METEORS. 
 
 between the fingers. On exposure to the air, how- 
 ever, they gradually hardened. The weight of the 
 largest fragment was 35 pounds. 
 
 (21.) 1859, November 15. Between 9 and 10 
 o'clock in the morning an extraordinary meteor 
 was seen in several of the New England States, 
 New York, New Jersey, the District of Columbia, 
 and Virginia. The apparent diameter of the head 
 was nearly equal to that of the sun, and it had a 
 train, notwithstanding the bright sunshine, several 
 degrees in length. Its disappearance on the coast 
 of the Atlantic was followed by a series of the most 
 terrific explosions. It is believed to have descended 
 into the water, probably into Delaware Bay. A 
 highly interesting account of this meteor, by Pro- 
 fessor Loomis, may be found in the American Jour- 
 nal of Science and Arts for January, 1860. 
 
 (22.) 1860, May 1. About 20 minutes before 1 
 o'clock, P.M., a shower of meteoric stones fell in the 
 southwest corner of Guernsey county, Ohio. Full 
 accounts of the phenomena are given in Silliman's 
 Journal for July, 1860, and January and July, 1861, 
 by Professors E. B. Andrews, E. W. Evans, J. L. 
 Smith, and D. W. Johnson. From these interesting 
 papers we learn that the course of the meteor was 
 about 40 west of north. Its visible track was over 
 Washington and Noble counties, and the prolonga- 
 tion of its projection, on the earth's surface, passes 
 directly through New Concord, in the southeast 
 corner of Muskingum county. The meteor when 
 first seen was about 40 miles from the earth's sur- 
 face. The sky, at the time, was for the most part 
 covered with clouds over northwestern Ohio, so 
 
METEORIC STONES. 63 
 
 that if any portion of the meteoric mass continued 
 on its course it was invisible. The velocity of the 
 meteor, in relation to the earth's surface, was from 
 three to four miles per second ; and hence its abso- 
 lute velocity in the solar system must have been 
 somewhat greater than that of the earth. 
 
 "At New Concord,* Muskingum county, where 
 the meteoric stones fell, and in the immediate 
 neighborhood, there were many distinct and loud 
 reports heard. At New Concord there was first 
 heard in the sky, a little southeast of the zenith, a 
 loud detonation, which was compared to that of a 
 cannon fired at the distance of half a mile. After 
 an interval of ten secondsy another similar report. 
 After two or three seconds another, and so on with 
 diminishing intervals. Twenty-three distinct 'de- 
 tonations were heard, after which the sounds be- 
 came blended together and were compared to the 
 rattling fire of an awkward squad of soldiers, and 
 by others to the roar of a railway train. These 
 sounds, with their reverberations, are thought to 
 have continued for two minutes. The last sounds 
 seemed to come from a point in the southeast 45 
 below the zenith. The result of this cannonading was 
 the falling of a large number of stony meteorites upon 
 an area of about 10 miles long by 3 wide. The sky 
 was cloudy, but some of the stones were seen first 
 as ' black specks', then as ' black birds', and finally 
 falling to the ground. A few were picked up within 
 20 or 30 minutes. The warmest was no warmer 
 
 * New Concord is close to the Guernsey county line. Nearly 
 all the stones fell in Guernsey. 
 
64 COMETS AND METEORS. 
 
 than if it had lain on the ground exposed to the 
 sun's rays. They penetrated the earth from two to 
 three feet. The largest stone, which weighed 103 
 pounds, struck the earth at the foot of a large oak- 
 tree, and, after cutting off two roots, one five inches 
 in diameter, and grazing a third root, it descended 
 two feet ten inches into hard clay. This stone was 
 found resting under a root that was not cut off. 
 This would seemingly imply that it entered the 
 earth obliquely." 
 
 Over thirty of the stones which fell were discov- 
 ered, while doubtless many, especially of the smaller, 
 being deeply buried beneath the soil, entirely es- 
 caped observation. The weight of the largest ten 
 was 418 pounds. 
 
 (23.) 1860, July 14. About 2 o'clock P.M. on 
 the 14th of July, 1860, a shower of aerolites fell at 
 Dhurmsala, in India. The fall was attended by a 
 tremendous detonation, which greatly terrified the 
 inhabitants of the district. The natives, supposing 
 the stones to have been thrown by some of their 
 deities from the summit of the Himalayas, carried 
 off many fragments to be kept as objects of religious 
 veneration. Lord Canning and Mr. J. R. Saunders 
 succeeded, however, in obtaining numerous speci- 
 mens, which they forwarded to the British Museum 
 and several European cabinets. They are earthy 
 aerolites, of a specific gravity somewhat greater 
 than that of granite. 
 
 (24.) 1864, May 14. Early in the evening a very 
 large and brilliant meteor was seen in France, 
 from Paris to the Spanish border. At Montauban 
 and in the vicinity loud explosions were heard, 
 
METEORIC STONES. 65 
 
 which were followed by showers of meteoric stones 
 near the villages of Orgueil and Nohic. The prin- 
 cipal facts in regard to the meteor are the following: 
 
 Elevation when first seen, over 55 miles 
 
 " at the time of its explosion 20 " 
 
 Inclination of its path to the horizon 20 or 25 
 
 Velocity per second, about 20 miles, 
 
 or equal to that of the earth's orbital motion. 
 
 "This example," says Professor Newton, "affords 
 the strongest proof that the detonating and stone- 
 producing meteors are phenomena not essentially 
 unlike." 
 
 (^5.) 1868, January 30. It is obviously a mat- 
 ter of much importance that the composition and 
 general characteristics of aerolites, together with 
 the phenomena attending their fall, should be care- 
 fully noted; as such facts have a direct bearing on 
 the theory of their origin. In this regard the me- 
 moirs of Professors J. Gr. Galle, of Breslau, and Gr. 
 vom Rath, of Bonn, on a meteoric fall which oc- 
 curred at Pultusk, Poland, on the 30th of January, 
 1868, have more than ordinary interest. These me- 
 moirs establish the fact that the aerolites of the 
 Pultusk shower entered our atmosphere as a swarm or 
 cluster of distinct meteoric masses. It is shown, 
 moreover, by Dr. Galle that this meteor-group had 
 a proper motion when it entered the solar system of 
 at least from 4J to 7 miles per second. 
 
 The foregoing list contains but a small proportion 
 of the meteoric stones whose fall has been actually 
 observed. But, besides these, other masses have 
 been found so closely similar in structure to aero- 
 lites whose descent has been witnessed, as to leave 
 
 6* 
 
66 COMETS AND METEORS. 
 
 no doubt in regard to their origin. One of these is 
 a mass of iron and nickel, weighing 1680 pounds, 
 found by the traveler Pallas, in 1749, at Abakansk, 
 in Siberia. This immense aerolite may be seen in 
 the Imperial Museum at St. Petersburg. On the 
 plain of Otumpa, in Buenos Ayres, is a meteoric 
 mass 7J feet in length, partly buried in the ground. 
 Its estimated weight is about 16 tons. A specimen 
 of this stone, weighing 1400 pounds, has been re- 
 moved and deposited in one of the rooms of the 
 British Museum. A similar block, of meteoric 
 origin, weighing more than six tons, was discov- 
 ered some years since in the province of Bahia, in 
 Brazil. 
 
 GENERAL REMARKS. 
 
 1. A Committee on Luminous Meteors was ap- 
 pointed several years since by the British Associa- 
 tion for the Advancement of Science. This com- 
 mittee, consisting at present of James Glaisher, 
 F.R.S., Robert P. Greg, F.R.S., Alexander S. Her- 
 schel, F.E.A.S., and Charles Brooke, F.R.S., report 
 from year to year not only their own observations 
 on aerolites, fire-balls, and falling stars, but also such 
 facts bearing upon the subject as can be derived 
 from other sources. An analysis of these reports 
 justifies the conclusion that meteoric stone-falls, like 
 star-showers, occur with greater frequency than 
 usual on or about particular days. These epochs, 
 established with more or less certainty, are the fol- 
 lowing : 
 
METEORIC STONES. 
 
 67 
 
 () 
 
 (6.) 
 (c.) 
 
 January 
 
 ) February 
 
 (/.) March 
 
 (9-) il 
 
 (A.) April 
 
 (i.) 
 
 (J.) May 
 
 (*) " 
 
 (Z.) " 
 (wi.) June 
 
 4th. 
 16th. 
 29th. 
 10th. 
 
 15th 18th. 
 
 6th. 
 
 12th. 
 
 1st. 
 
 10th 14th. 
 
 8th 9th. 
 
 13th 14th. 
 
 17th 19th. 
 
 3d. 
 
 9th. 
 
 (o.) June 
 (p.) 
 (q.) July 
 (r.) 
 (s.) August 
 
 12th. 
 
 16th. 
 
 3d 4th. 
 
 14th 17th. 
 
 5th 7th. 
 
 llth. 
 
 4th 10th. 
 13th. 
 5th. 
 
 12th 13th. 
 27th 30th. 
 5th. 
 
 8th 14th. 
 27th. 
 
 (w.) September 
 (17.) October 
 (w>.) November 
 
 (*) " 
 
 (2/0 " 
 
 (z.) December 
 
 (*'.) 
 
 (*".) 
 
 2. It is worthy of remark that no new elements 
 have been found in meteoric stones. Humboldt, in 
 his " Cosmos," called attention to this interesting 
 fact. " I would ask," he remarks, " why the elemen- 
 tary substances that compose one group of cosmical 
 bodies, or one planetary system, may not in a great 
 measure be identical? Why should we not adopt 
 this view, since we may conjecture that those plan- 
 etary bodies, like all the larger or smaller agglom- 
 erated masses revolving round the sun, have been 
 thrown off from the once far more expanded solar 
 atmosphere, and have been formed from vaporous 
 rings describing their orbits round the central body?" 
 
 3. But while aerolites contain no elements but 
 such as are found in the earth's crust, the manner 
 in which these elements are combined and arranged 
 is so peculiar that a skillful mineralogist will readily 
 distinguish them from terrestrial substances. 
 
 4. Of the eighteen or nineteen elements hitherto 
 observed in meteoric stones, iron is found in the 
 greatest abundance. The specific gravities vary from 
 1.94 to 7.90J. : the former being that of the stone of 
 
68 COMETS AND METEORS. 
 
 Alais; the latter that of the meteorite of Wayne 
 county, Ohio, described by Professor J. L. Smith in 
 SUliman's Journal for November, 1864, p. 385. 
 
 5. The average number of aerolitic falls in a year 
 was estimated by Schreibers at 700. Baron Reichen- 
 bach, however, after a discussion of the data at hand, 
 makes the number much larger. He regards the 
 probable annual average for the entire surface of the 
 earth as not less than 4500. This would give twelve 
 daily falls. They are of every variety as to. magni- 
 tude, from a weight of less than a single ounce to over 
 fifteen tons. The baron even suspects the meteoric 
 origin of large masses of dolerite which all former 
 geologists had considered native to our planet. 
 
 6. An analysis of any extensive table of meteor- 
 ites and fire-balls proves that a greater number of 
 aerolitic falls have been observed during the months 
 of June and July, when the earth is near its aphe- 
 lion, than in December and January, when near its 
 perihelion. It is found, however, that the reverse 
 is true in regard to bolides, or fire-balls. These 
 facts are susceptible of an obvious explanation. The 
 fall of meteoric stones would be more likely to escape 
 observation by night than by day, on account of the 
 relatively small number of observers. But the days 
 are shortest when the earth is in perihelion, and 
 longest when in aphelion; the ratio of their lengths 
 being nearly equal to that of the corresponding num- 
 bers of aerolitic falls. On the other hand, it is obvious 
 that fire-balls, unless very large, would not be visible 
 during the day. The observed number will therefore 
 be greatest when the nights are longest; that is, 
 when the earth is near its perihelion. This, it will be 
 found, is precisely in accordance with observation. 
 
CHAPTEE VIII. 
 
 . SHOOTING-STARS. METEORS OF NOVEMBER 14. 
 
 ALTHOUGH shooting-stars have doubtless been ob- 
 served in all ages of the world, it is only within the 
 last half century that they have attracted the special 
 attention of scientific men. A few efforts had been 
 made to determine the height of such meteors, but 
 the first general interest in the subject was excited 
 by the brilliant meteoric display of November 13, 
 1833. This shower of fire can never be forgotten 
 by those who witnessed it. The meteors were ob- 
 served from the West Indies to British America, 
 and from 60 to 100 west longitude from Green- 
 wich. As early as 10 o'clock on the evening of the 
 12th shooting-stars were observed with unusual fre- 
 quency; their motions being generally westward. 
 Soon after midnight their numbers became so ex- 
 traordinary as to attract the attention of all who 
 happened to be in the open air. The meteors, how- 
 ever, became more and more numerous till 4, or 
 half past 4, o'clock ; and the fall did not entirely 
 cease till ten minutes before sunrise. From 2 to 6 
 o'clock the numbers were so great as to defy all 
 efforts at counting them ; while their brilliancy was 
 such that persons sleeping in rooms with uncur- 
 tained windows were aroused by their light. The 
 
 69 
 
70 COMETS AND METEORS. 
 
 meteors varied in apparent magnitude from the 
 smallest visible points to fire-balls equaling the moon 
 in diameter. Occasionally one of the larger class 
 would separate into several parts, and in some in- 
 stances a luminous train remained visible for three or 
 four minutes. ~No sound whatever accompanied the 
 display. It was noticed by many observers that all 
 the meteors diverged from a point near the star 
 Gamma Leonis ; in other words, their paths if traced 
 backward would intersect each other at a particular 
 locality in the constellation Leo. In some parts of 
 the country the inhabitants were completely terror- 
 stricken by the magnificence of the display. In the 
 afternoon of the day on which the shower occurred 
 the writer met with an illiterate farmer who, after 
 describing the phenomena as witnessed by himself, 
 remarked that " the stars continued to fall till none 
 were left," and added, " I am anxious to see how 
 the heavens will appear this evening; I believe we 
 shall see no more stars." A gentleman of South 
 Carolina described the effect on the negroes of his 
 plantation as follows: " I was suddenly awakened 
 by the most distressing cries that ever fell on my 
 ears. Shrieks of horror and cries for mercy I could 
 hear from most of the negroes of the three planta- 
 tions, amounting in all to about 600 or 800. While 
 earnestly listening for the cause I heard a faint 
 voice near the door, calling my name. I arose, and, 
 taking my sword, stood at the door. At this mo- 
 ment I heard the same voice still beseeching me to 
 arise, and saying, l my Grod, the world is on fire !' 
 I then opened the door, and it is difficult to say 
 which excited me the most, the awfulness of the 
 
SHOOTING-STARS. 71 
 
 scene, or the distressed cries of the negroes. Up- 
 wards of a hundred lay prostrate on the ground, 
 some speechless, and some with the bitterest cries, 
 but with their hands raised, imploring God to save 
 the world and them. The scene was truly awful ; for 
 never did rain fall much thicker than the meteors 
 fell towards the earth ; east, west, north, and south, 
 it was the same." 
 
 At the time of this wonderful meteoric display 
 Captain Hammond, of the ship Restitution, had just 
 arrived at Salem, Massachusetts, where he observed 
 the phenomenon from midnight till daylight. He 
 recollected with astonishment that precisely one 
 year before, viz., on the 13th of November, 1832, he 
 had observed a similar appearance (although the 
 meteors were less numerous) at Mocha, in Arabia. 
 It was found, moreover, as a further and most re- 
 markable coincidence, that an extraordinary fall of 
 meteors had been witnessed on the 12th of Novem- 
 ber, 1799. This was seen and described by Andrew 
 Ellicott, Esq., who was then at sea near Cape 
 Florida. It was also observed by Humboldt and 
 Boupland, in Cumana, South America. Baron 
 Humboldt's description of the shower is as follows : 
 "From half after two, the most extraordinary lumin- 
 ous meteors were seen toward the east. Thousands 
 of bolides and falling stars succeeded each other 
 during four hours. They filled a space in the sky 
 extending from the true east 30 toward the north 
 and south. In an amplitude of 60 the meteors 
 were seen to rise above the horizon at E.N.E. and 
 at E., describe arcs more or less extended, and fall 
 toward the south, after having followed the direc- 
 
72 COMETS AND METEORS. 
 
 tion of the meridian. Some of them attained a 
 height of 40, and all exceeded 25 or 30. Mr. 
 Bonpland relates, that from the beginning of the 
 phenomenon there was not a space in the firmament 
 equal in extent to three diameters of the moon, that 
 was not filled at every instant with bolides and fall- 
 ing stars. The Guaiqueries in the Indian suburb 
 came out and asserted that the firework had begun 
 at one o'clock. The phenomenon ceased by degrees 
 after four o'clock, and the bolides and falling stars 
 became less frequent; but we still distinguished 
 some toward the northeast a quarter of an hour 
 after sunrise." 
 
 This wonderful correspondence of dates excited 
 a very lively interest throughout the scientific world. 
 It was inferred that a recurrence of the phenomenon 
 might be expected, and accordingly arrangements 
 were made for systematic observations on the 12th, 
 13th, and 14th of November. The periodicity of 
 the shower was thus, in a very short time, placed 
 wholly beyond question. The facts in regard to 
 the phenomena of November 13, 1833, were col- 
 lected and discussed by Ol mated, Twining, and 
 other astronomers. The inquiry, however, very 
 naturally arose whether any trace of the same me- 
 teoric group could be found in ancient times. To 
 determine this question many old historical records 
 were ransacked by the indefatigable scientist, Ed- 
 ward C. Herrick, in our own country, and by Arago, 
 Quetelet, and others, in Europe. These examina- 
 tions led to the discovery of ten undoubted returns 
 of the November shower previous to that of 1799. 
 The descriptions of these former meteoric falls are 
 
SHOOTING-STARS. 73 
 
 given by Professor II. A. Newton in the American 
 Journal of Science, for May, 1864. They occurred 
 in the years 902, 931, 934, 1002, 1101, 1202, 1366, 
 1533, 1602, and 1698. Historians represent the me- 
 teors of A.D. 902 as innumerable, and as moving 
 like rain in all directions. The exhibition of 1202 
 was scarcely less magnificent. "On the last day of 
 Muharrem," says a writer of that period, " stars 
 shot hither and thither in the heavens, eastward and 
 westward, and flew against one another like a scat- 
 tering swarm of locusts, to the right and left; this 
 phenomenon lasted until daybreak; people were 
 thrown into consternation, and cried to God the 
 Most High with confused clamor." The shower of 
 1366 is thus described in a Portuguese chronicle, 
 quoted byllumboldt: "In the year 1366, twenty- 
 two days of the month of October being past, three 
 months before the death of the king, Don Pedro 
 (of Portugal), there was in the heavens a movement 
 of stars such as men never before saw or heard of. 
 At midnight, and for some time after, all the stars 
 moved from the east to the west; and after beino- 
 
 o 
 
 collected together, they began to move, some in one 
 direction and others in another. And afterward 
 they fell from the sky in such numbers, and so 
 thickly together, that as they descended low in the 
 air they seemed large and fiery, and the sky and 
 the air seemed to be in flames, and even the earth 
 appeared as if ready to take fire. That portion of 
 the sky where there were no stars seemed to be 
 divided into many parts, and this lasted for a long 
 time." 
 
 t 
 
74 COMETS AND METEORS. 
 
 The Showers of 1866-9. 
 
 The fact that all great displays of the November 
 meteors have taken place at intervals of 33 or 34 
 years, or some multiple of that period, had led to a 
 general expectation of a brilliant shower in 1866. 
 In this country, however, the public curiosity was 
 much disappointed.* The numbers seen were 
 greater than on ordinary nights, but not such as 
 would have attracted any special attention. The 
 greatest number recorded at any one station was 
 seen at New Haven by Professor Newton. On the 
 night of the 12th 694 were counted in five hours and 
 twenty minutes, and on the following night, 881 in 
 five hours. A more brilliant display was, however, 
 witnessed in Europe. Meteors began to appear in 
 unusual frequency about 11 o'clock on the night of 
 the 13th, and their numbers continued to increase 
 with great rapidity for more than two hours ; the 
 maximum being reached a little after 1 o'clock. A 
 writer in Edinburgh, Scotland, thus describes the 
 phenomenon as observed at that city: "Standing 
 on the Calton Hill, and looking westward, with 
 the observatory shutting out the lights of Princes 
 Street, it was easy for the eye to delude the im- 
 agination into fancying some distant enemy bom- 
 barding Edinburgh Castle from long range; and 
 the occasional cessation of the shower for a few 
 
 * The first indication of the approaching shower was the ap- 
 pearance of meteors in unusual numbers at Malta, on the 13th of 
 November, 1864. In 1865, as observed at Greenwich and other 
 stations, they were still more numerous. 
 
SHOOTING-STARS. 75 
 
 seconds, only to break out again with more numer- 
 ous and more brilliant drops of tire, served to coun- 
 tenance this fancy. Again, turning eastward, it was 
 possible now and then to catch broken glimpses of 
 the train of one of the meteors through the grim 
 dark pillars of that ruin of most successful manu- 
 facture, the National Monument; and in fact from 
 no point in or out of the city was it possible to 
 watch the strange rain of stars, pervading as it did 
 all points of the heavens, without pleased interest 
 and a kindling of the imagination, and often a 
 touch of deeper feeling that bordered on awe." At 
 London about 1 o'clock a single observer counted 
 200 in two minutes. The whole number seen at 
 Greenwich was 8485. The shower was also observed 
 in different countries on the continent. 
 
 In 1867 the display was generally observed 
 throughout the United States. From the able and 
 interesting reports of Commodore Sands and Pro- 
 fessors Newcomb, Harkness, and Eastman, we de- 
 rive the following facts in regard to the shower as 
 seen at Washington, D. C.: 
 
 Commencement \h. Om. A.M. Nov. 14. 
 
 Maximum 4 20 " " 
 
 End 5 " " 
 
 Number of meteors per hour at maximum 3000 
 
 Mean height on first appearance 75 miles. 
 
 " u on disappearance 55 " 
 
 Position of radiant, R. A. 151, Decl. 22 . 
 
 The shower of 1868 was in some respects quite 
 remarkable, though the number of meteors was less 
 than in 1866 or 1867. At New Haven the fall com- 
 menced about midnight, and from 2 o'clock till day- 
 
76 COMETS AND METEORS. 
 
 break over 5000 meteors were counted. The time 
 of maximum could not be accurately determined, 
 as no decrease in the numbers was observable till 
 dawn. The display was also witnessed in England 
 and in Cape Colony, South Africa. The times of 
 maxima in these countries differed so materially as 
 to indicate a decided stratification of the meteoric 
 stream. The entire depth, moreover, where crossed 
 by the earth in 1868, was much greater than at the 
 part traversed either iu 18d6 or 1867. 
 
 In 1869 the shower was observed at Port Sa'id, 
 Lower Egypt, by G. L. Tupman, Esq.; in Florida, 
 U. S., by Commander William Gibson, TJ.S.K ; 
 and at Santa Barbara, California, by Mr. G. David- 
 son and Mrs. E. Davidson. The first observed 112 
 meteors in Ih. 54m., from 2h. 30m. to 4h. 24m., 
 Alexandria mean time; the numbers during this 
 interval being nearly equal, though slightly decreas- 
 ing. Throughout the morning (November 14) the 
 sky was only partly clear. The two observers 
 at Santa Barbara saw 556 in 2h. 25rn., ending at 
 3h. 43m. A.M. In Florida also the display was 
 quite brilliant, though inferior to that of 1868. It 
 should be remarked that the morning in many parts 
 of the United States was cloudy. No considerable 
 number of the meteors of this stream has been ob- 
 served in any part of the world since 1869. 
 
 DISCUSSION OF THE PHENOMENA. 
 
 Since the memorable display of November 13, 
 1833, the phenomena of shooting-stars have been 
 observed and discussed with a very lively interest. 
 
SHOOTING-STARS. 77 
 
 Among the first laborers in this department of re- 
 search the names of Olmsted, Herrick, and Twin- 
 ing must ever hold a conspicuous place. The fact 
 that the position of the radiant point did not change 
 with the earth's rotation at once placed the cosmi- 
 cal origin of the meteors wholly beyond question. 
 The theory of a ring of nebulous matter revolving 
 round the sun in an elliptic orbit a theory some- 
 what different from that proposed by Olmsted 
 was found to afford a simple and satisfactory 
 explanation of the phenomena. This hypothesis 
 of an eccentric stream of meteors intersecting the 
 earth's orbit was adopted by Humboldt, Arago, and 
 others, shortly after the occurrence of the meteoric 
 shower of 1833. 
 
 A few years previous to the display of 1866 it 
 was shown by Professor Newton, of Yale College, 
 that the distribution of meteoric matter around the 
 ring or orbit is far from uniform ; that the motion 
 is retrograde ; that the node of the orbit has an an- 
 nual forward motion of 102".6 with respect to the 
 equinox, or of 52". 4 with respect to the fixed stars ; 
 that the periodic time must be limited to five 
 accurately determined periods, viz.: 180.05 days, 
 185.54 days, 354.62 days, 376.5 days, or 33.25 years; 
 and that the inclination of the orbit to the ecliptic 
 is about 17. Professor Newton, for reasons as- 
 signed, regarded the third period named as the 
 most probable. He remarked, however, that by 
 computing the secular motion of the node for each 
 periodic time, and comparing the result with the 
 known precession, it was possible to determine 
 which of the five periods is the correct one. 
 
 7* 
 
78 COMETS AND METEORS. 
 
 For the application of this crucial test, a prob- 
 lem of more than ordinary interest, we are in- 
 debted to Professor J. 0. Adams, of Cambridge, 
 England. By an elegant analysis it was first shown 
 that for either of the iirst four periods designated 
 by Professor Newton, the annual motion of the 
 node, resulting from planetary perturbation, would 
 be considerably less than one half of the observed 
 motion. It only remained, therefore, to examine 
 whether the period of 33J years would give a mo- 
 tion of the node corresponding with observation. 
 Professor Adams found that in this time the longi- 
 tude of the node is increased 20' by the action of 
 Jupiter, V by the action of Saturn, and V by that 
 of Uranus. The effect of the other planets is 
 scarcely perceptible. The calculated motion in 33 J 
 years is therefore 28'. The observed motion in the 
 same time, according to Professor Newton, as pre- 
 viously stated, is 29'. This remarkable accordance 
 was at once accepted by astronomers as satisfactory 
 evidence that the period is about 33.25 years. 
 
 Having determined the periodic time, the mean 
 distance, or semi-axis major, is found by Kepler's 
 third law to be 10.34. The aphelion is consequently 
 situated at a comparatively short distance beyond the 
 orbit of Uranus. The orbit is represented in Fig. 4. 
 
 It was stated at the close of Chapter VI. that 
 shooting-stars are the dissevered fragments of 
 cometic matter, which, penetrating our atmosphere, 
 are rendered luminous by the resistance so encoun- 
 tered. The discovery that comets and meteors are 
 actually moving in the same orbits was first an- 
 nounced by Signor Schiaparelli in 1867. The 
 
SHOOTING-STARS. 
 
 79 
 
 coincidence of the orbits of Tempel's comet* as 
 computed by Dr. Oppolzer, and the meteors of 
 
 Fig. 4. 
 
 November 14 as determined by Schiaparelli, is 
 too close to be regarded as merely accidental. 
 These elements are as follows : 
 
 Nov. Meteors. Tempel's Comet. 
 
 Perihelion passage Nov. 10.092, 1866. Jan. 11.160, 1866. 
 
 Passage of descending node. Nov. 13.576, 
 
 Longitude of perihelion 56 26' 60 28' 
 
 Longitude of ascending node... 231 28' 231 26' 
 
 * See page 30. 
 
80 .COMETS AND METEORS. 
 
 Nov. Meteors. Tempers Comet. 
 
 Inclination 17 44' 17 18' 
 
 Perihelion distance 0.9873 0.9765 
 
 Eccentricity 0.9046 0.9054 
 
 Semi-major axis 10.3400 10.3240 
 
 Periodic time 33.2500 y. 33.1760 y. 
 
 Motion Retrograde. Retrograde. 
 
 The fact is thus obvious that the meteors of No- 
 vember 14 are the products of the comet's gradual 
 dissolution. It has been stated that the comets of 
 1366 and 1866 are probably identical. The interval 
 indicates a period of 33.283 years greater by 39 
 days than that found by Oppolzer. With this 
 value of the periodic time and the known secular 
 variation of the node it is found that the cornet 
 and Uranus were in close proximity about the be- 
 ginning of the year 547 B.C. It is therefore not im- 
 probable that the former was then thrown into its 
 present orbit by the attraction of the latter. The 
 celebrated Leverrier designated the year 126 of our 
 era as the probable epoch of the comet's entrance 
 into our system. This date, however, is incompat- 
 ible with the period here adopted. It is worthy of 
 remark, moreover, as bearing on this question, that 
 the extension of the cluster in the tenth century, as 
 indicated by the showers of 902, 931, and 934, was 
 too great to have been effected in so short a period 
 as 800 years. 
 
 With the period of 33.283 years it is easy to find 
 that the comet will make a near approach to the earth 
 about the 16th or 17th of November, 1965, and to 
 Uranus in 1983. At one of these epochs the comet- 
 ary orbit will probably undergo considerable trans- 
 formation. 
 
SHOOTING-STARS. 81 
 
 "We have seen that the comet of 1866, and also 
 the meteoroids following in its path, have their 
 perihelion at the orbit of the earth, and their aphe- 
 lion at the orbit of Uranus. Both planets, therefore, 
 at each encounter with the current not only appro- 
 priate a portion of the meteoric matter, but entirely 
 change the orbits of many meteoroids. In regard 
 to the devastation produced by the earth in passing 
 through the cluster, it is sufficient to state that, ac- 
 cording to Weiss, the meteor orbits resulting from 
 the disturbance will have all possible periods from 
 21 months to 390 years. It may be regarded, there- 
 fore, as evidence of the recent* introduction of this 
 meteor-stream into the solar system that the comet 
 of 1866, which constitutes a part of the cluster, has 
 not been deflected from the meteoric orbit by either 
 the earth or Uranus. 
 
 * Recent in comparison with the origin of the August meteors, 
 which constitute a continuous ring. 
 
CHAPTER IX. 
 
 OTHER METEORIC STREAMS. 
 
 The Meteors of August 7-11. Muschenbroek, in 
 his "Introduction to Natural Philosophy," published 
 in 1762, stated as the result of his own observations 
 that shooting-stars are more abundant in August 
 than in any other part of the year. The fact, how- 
 ever, that a maximum occurs on the 9th or 10th of 
 the month was first shown by Quetelet in 1835. 
 Since that time the shower has been regularly ob- 
 served both in Europe and America; the number 
 of meteors at the maximum sometimes amounting 
 to 160 per hour. Their tracks when produced back- 
 ward intersect each other at a particular point in 
 the constellation Perseus. 
 
 Of the 315 meteoric displays given in Quetelet's 
 catalogue, 63 belong to the August epoch. Their 
 dates up to the commencement of the present cen- 
 tury are as follows : 
 
 1. 
 
 2. 
 3. 
 4. 
 5. 
 6. 
 7. 
 8. 
 9. 
 10. 
 
 A.D. 811, July 25th. 
 
 820, 
 
 25th-30th. 
 
 824, 
 
 26th-28th. 
 
 830, 
 
 26th. 
 
 833, 
 
 27th. 
 
 835, 
 
 26th. 
 
 841, 
 
 25th-30th 
 
 924, 
 
 27th-30th. 
 
 925, 
 
 27th-30th. 
 
 926, 
 
 27th-30th. 
 
 82 
 
OTHER, METEORIC STREAMS. 83 
 
 11. AD. 933, July 25th-30th. 
 
 12 1243, Aug. 2d. 
 
 13 1451, 7th. 
 
 14 1709, 8th. 
 
 15 1779, 9th-10th. 
 
 16 1781, " 8th. 
 
 17 1784, " 6th-9th. 
 
 18 1789, " 10th. 
 
 19 1798, 9th. 
 
 20 1799, " 9th-10th. 
 
 21 1800, " 10th. 
 
 As the earth is about five days in crossing the 
 ring, its breadth in some parts cannot be less than 
 8,000,000 miles. 
 
 In 1866 Professor Schiaparelli, on computing the 
 orbit of this meteoric stream, noticed the remark- 
 able agreement of its elements with those of Swift's 
 or Tattle's comet* (1862,111.), as computed by Dr. 
 Oppolzer. These coincidences are exhibited in the 
 following table: 
 
 Meteors of August 10. Comet III. of 1862. 
 
 Longitude of perihelion 343 38 7 344 41' 
 
 Ascending node 138 16' 137 27' 
 
 Inclination 63 3' 66 25' 
 
 Perihelion distance 0.9643 0.9626. 
 
 Period 105 years (?) 121.5 years. 
 
 Motion Retrograde. Retrograde. 
 
 It appears, therefore, that the third comet of 1862 
 is a part of the meteoric stream whose orbit is 
 crossed by the earth on the 10th of August. 
 
 The characteristics of different meteor-zones afford 
 interesting indications in regard to their relative age, 
 
 * Mr. Swift, of Marathon, N. Y., had two or three days pri- 
 ority in the discovery of this comet, but unfortunately delayed 
 his announcement of the fact. 
 
84 COMETS AND METEORS. 
 
 the magnitude and composition of their corpus- 
 cles, etc. Thus, if we compare the streams of 
 August 10 and November 14, we shall find that 
 the former probably entered our system at a com- 
 paratively remote epoch. We have seen that at each 
 return to perihelion the meteoric cluster is extended 
 over a greater arc of its orbit. Now, Tattle's comet 
 and the August meteors undoubtedly constituted a 
 single group previous to their entering the solar 
 domain. It is evident, however, from the annual 
 return of the shower during the last 90 years, that 
 the ring is at present nearly if not quite continuous. 
 That the meteoric mass had completed many revo- 
 lutions before the ninth century of our era is mani- 
 fest from the frequent showers observed between 
 the years 811 and 841. At the same time, the long 
 interval of 83 years between the last observed dis- 
 play in the ninth century, and the first in the tenth, 
 seems to indicate the existence of a wide chasm in 
 the ring no more than a thousand years since. 
 
 Neither the period of the meteors nor that of the 
 comet can yet be regarded as accurately ascertained. 
 The latter, however, in all probability, exceeds the 
 former by several years. Now, at each passage of 
 the earth through the elliptic stream, those meteor- 
 oids nearest the disturbing body must be thrown 
 into orbits differing more or less from that of the 
 primitive group. In like manner the near approach 
 of the comet to the earth at an ancient epoch may 
 account for the lengthening of its periodic time. 
 
OTHER METEORIC STREAMS. 85 
 
 The Meteors of November 27. 
 
 Professor Scbiaparelli's brilliant discovery of the 
 relation between comets and meteors may now be 
 ranked with the established truths of astronomy. 
 His hypothesis, however, in regard to the origin of 
 meteoric streams has not been generally accepted. 
 Comets and meteors, according to. his theory, are 
 derived from cosmical clouds existing in great num- 
 bers in stellar space. These nebulae, in consequence 
 of their own motion or that of the sun, are drawn 
 towards the centre of our system. By the unequal 
 influence of the sun's attraction on different parts, 
 such clouds are transformed into currents of great 
 length before reaching the limits of the planetary 
 system. Shooting -stars, fire-balls, aerolites, and 
 comets being all of the same nature, differing merely 
 in size, sometimes fall towards the sun as parts of 
 the same current. 
 
 The views of Dr. Weiss, of Vienna, differ from 
 those of Schiaparelli, in that he regards comets as 
 the original bodies by whose disintegration meteor- 
 streams are gradually formed.* " Cosmical clouds," 
 he remarks, " undoubtedly appear in the universe, 
 but only of such density that in most cases they 
 possess sufficient coherence to withstand the destruc- 
 tive operation of the sun's attraction, not only up 
 to the boundaries of our solar system, but even 
 within it. Such cosmical clouds will always appear 
 to us as comets when they pass near enough to the 
 
 * Astr. Nach., Nos. 1710, 1711. For a fuller statement of 
 Schiaparelli's theory, see Silliman's Journal for May, 1867. 
 
 8 
 
86 COMETS AND METEORS. 
 
 earth to become visible. Approaching the sun, 
 the comet undergoes great physical changes, which 
 finally affect the stability of its structure : it can no 
 longer hold together: parts of it take independent 
 orbits around the sun, having great resemblance to 
 the orbit of the parent comet. "With periodical 
 comets, this process is repeated at each successive 
 approach to the sun. Gradually the products of 
 disintegration are distributed along the comet's 
 orbit, and if the earth's orbit cuts this, the phe- 
 nomenon of shooting-stars is produced." 
 
 These views of the distinguished astronomer of 
 Vienna are confirmed by the star-shower of Novem- 
 ber 27, 1872. That the orbits of the earth and 
 Biela's comet intersect at the point passed by the 
 former about the last of November, and that in 
 1845 the comet separated into two visible parts, has 
 been stated in a 'previous chapter. The comet's 
 non-appearance in December, 1865, and in Septem- 
 ber, 1872, was regarded by astronomers as presump- 
 tive evidence of its progressive dissolution. A me- 
 teoric shower, resulting from the earth's collision 
 with the cometary debris, was accordingly expected 
 about the 27th of November. 
 
 The first indication of the approaching display 
 appeared on the evening of November 24, when 
 meteors in unusual numbers were observed by Pro- 
 fessor Newton, at New Haven, Connecticut. On 
 Wednesday evening, the 27th, from the close of 
 twilight till 8 o'clock, a decided shower of shooting- 
 stars was noticed in various parts of the United 
 States. At Greencastle, Indiana, Professor Joseph 
 Tingiey counted 110 meteors in 40 minutes, and at 
 
OTHER METEORIC STREAMS. 87 
 
 Princeton, in the same State, Mr. D. Eckley Hunter 
 counted 70 in 80 minutes. The numbers seen at 
 New Haven were considerably greater. The fact 
 that the display commenced before daylight had 
 entirely closed seemed to indicate that only the 
 termination of the shower had been observed in 
 this country. Accordingly the display was soon 
 found to have been witnessed from 60 E. to 90 W. 
 of Greenwich, or through 150 of longitude. In 
 England the first bolide of the swarm was seen by 
 M. M. Brinkley, at 3 o'clock, P.M., in full daylight. 
 The meteors were most numerous in the southern 
 part of the continent, particularly in Italy. At the 
 Observatory of Breslau, according to M. Faye, 3000 
 were seen from 6h. 30m. to 7h. 50m. Dr. Heis re- 
 ported that at Miinster 2500 per hour were counted 
 by two observers. At Naples, Signor Gasparis ob- 
 served two meteors per second. At Turin, M. Denza, 
 Director of the Observatory, reported 33,400 in 6h. 
 30m.; many of various and delicate colors, and 
 followed by long and brilliant trains. At some 
 points the numbers were so great that an accurate 
 enumeration was wholly impossible. In short, the 
 display was decidedly the most brilliant that has 
 occurred since that of November 13, 1833. 
 . But some of the most interesting circumstances 
 in connection with the phenomena of November 
 27, 1872, remain to be detailed. Astronomers with- 
 out exception regarded the display as due to the 
 earth's passage through the debris following in the 
 path of Biela's comet. In accordance with this view 
 Dr. Klinkerfues, of Gottingen, concluded that the 
 comet itself, or rather its largest portion, ought to 
 
88 COMETS AND METEORS. 
 
 be found in the region of the heavens nearly opposite 
 to that from which the meteoroids appeared to radi- 
 ate.* As this point in the southern hemisphere 
 could not he observed in Europe, he conceived the 
 happy idea of detecting the fugitive by means of the 
 electric telegraph. The following was accordingly dis- 
 patched to Mr. Pogson, Director of the Government 
 Observatory at Madras, in Southern India: "Biela 
 touched earth on 27th; search near Theta Centauri." The 
 first two mornings after the receipt of this dispatch 
 were cloudy at Madras. On the third, however, the 
 cometary fragment was found, and its motion ac- 
 curately measured. The observer described it as 
 circular and rather bright, with no traces of a tail. 
 But one fragment could be detected. On the next 
 morning, December 3, the comet was again observed. 
 Its diameter had sensibly increased ; it had a bright 
 nucleus, and still presented a circular aspect. A faint 
 tail was also noticed, equal in length to one-fourth 
 of the moon's apparent diameter. The following 
 mornings being again cloudy, no further observa- 
 tions could be obtained. This cometary mass will 
 be in close proximity to the earth about the last of 
 November, 1892. Another brilliant meteoric shower 
 may therefore be expected at that epoch. 
 
 The Meteors of April 20. 
 
 Meteoric showers have occurred about the 20th 
 of April in the following years : 
 
 * The radiant of the Eiela meteors is near Gamma Andromedse. 
 
OTHER METEORIC STREAMS. 89 
 
 B.C. 687 
 
 15 
 
 A.D. 582 
 
 1093 
 
 1094 
 
 1095 
 
 1096 
 
 1122) 
 
 1123] 
 
 1803 
 
 The probability that these meteors are derived 
 from a ring which intersects the earth's orbit, was 
 first suggested by Arago in 1836. A comparison of 
 dates led Herrick to designate 27 years as the proba- 
 ble period of the cluster. In the Astronomische Nach- 
 richten, No. 1632, Dr. Weiss called attention to the 
 fact that the orbit of the first comet of 1861 very 
 nearly intersects that of the earth, in longitude 
 210 the point passed by the latter at the epoch 
 of the April meteoric shower. A relation between 
 the meteors and the comet, indicating an approx- 
 imate equality of periods, was thus suggested as 
 probable. But the come, according to Oppolzer, 
 does not complete a revolution in less than 415 
 years. If, therefore, the meteoric period is nearly 
 the same, the known dates of star-showers indicate 
 a diffusion of meteoroids around one half of the 
 orbit previous to the display of the year 15 B.C. No 
 subsequent perturbation, then, of a particular part 
 could sensibly afiect the general orbit of the stream. 
 The infrequency of the display renders, therefore, 
 the hypothesis of a long period extremely improb- 
 able. 
 
 The entire interval between 687 B.C. and A.D. 1803 
 8* 
 
90 COMETS AND METEORS. 
 
 is 2490 years, or 92 periods of 27.0652 years; and 
 the known dates are all satisfied by the following 
 scheme : 
 
 B.C. 687 to B.C. 15.... 672 years = 25 periods of 26.8800 y. each. 
 15 to A.D. 582... .597 " =22 27.1363 " 
 
 A.D. 582 to 1095... .513 " =19 " 27.0000 " 
 1095 to 1122.... 27 " = 1 " 27.0000 " 
 1122 to 1803... .681 " =25 " 27.2400 
 
 With a period of 27 years, the perihelion being 
 interior to the earth's orbit, the aphelion distance of 
 the meteors would be very nearly equal to the dis- 
 tance of Uranus. The next shower, if the assumed 
 period be correct, ought to occur about 1884. It is 
 worthy of remark that near the time of the last 
 (hypothetical) return Mr. Du Chaillu witnessed the 
 meteors of this epoch, in considerable numbers, in 
 the interior of Africa. 
 
 The Meteors of December 12. 
 
 Meteoric showers have occurred about the 12th 
 of December in the following years: 
 
 1. A.D. 901. "The whole hemisphere was filled 
 with those meteors called falling-stars from mid- 
 night till morning, to the great surprise of the be- 
 holders in Egypt." 
 
 2. In 930 a remarkable shower of falling stars 
 was observed in China. 
 
 3. Extraordinary meteoric phenomena were ob- 
 served at Zurich at the same epoch in 1571. 
 
 4. On the night of the llth and 12th of Decem- 
 ber, 1833, a great number of shooting-stars were 
 
OTHER METEORIC STREAMS. 91 
 
 seen at Parma. At the maximum as many as ten 
 were visible at the same time. 
 
 5. (Doubtful.) 1861, 1862, and 1863. Maximum 
 probably in 1862. The meteors at this return were 
 far from being comparable in numbers with the an- 
 cient displays. The shower, however, was distinctly 
 observed. E. P. Greg, Esq., of Manchester, Eng- 
 land, says the period of December 12, 1862, was 
 " exceedingly well defined." 
 
 These dates indicate a period of about 29J years. 
 Thus: 
 
 901 to 930 1 period of 29.000 years. 
 
 930 to 1571 22 periods of 29.136 " 
 
 1571 to 1833 9 periods of 29.111 " 
 
 1833 to 1862 1 period of 29.000 " 
 
 Meteors of October 16-20. 
 
 Meteoric showers were observed from the 16th to 
 the 20th of October in the years 288, 1436, 1439, 
 1743, and 1798. These dates render it somewhat 
 probable that the period is about 27 J years. Thus : 
 
 A.D. 288 to 1439 42 periods of 27.405 years each. 
 
 1439 to 1743.. 11 " 27.636 " " 
 
 1743 to 1798 2 " 27.500 " " 
 
 If these periods are correct, it is a remarkable 
 coincidence that the aphelion distances of the me- 
 teoric rings of April 20, October 18, November 14, 
 and December 12, as well as those of the comets 
 1866 L, and 1867 I., are all nearly equal to the 
 mean distance of Uranus. 
 
92 COMETS AND METEORS. 
 
 The Meteors of April 30, May 1. 
 
 Professor Schiaparelli, in his list of meteoric 
 showers whose radiant points are derived from ob- 
 servations made in Italy during the years 1868, 1869, 
 and 1870, describes one as occurring on April 30 
 and May 1; the radiant being in the Northern 
 Crown. The same shower has also been recognized 
 by R. P. Greg, F.R.S., of Manchester, England. 
 This meteor-stream, it is now proposed to show, is 
 probably derived from one much more conspicuous 
 in ancient times. 
 
 In Quetelet's " Physique du Globe" we find mete- 
 oric displays of the following dates. In each case the 
 corresponding day for 1870 is also given,* in order 
 to exhibit the close agreement of the epochs : 
 
 1. A.D. 401, April 9th; corresponding to April 29th, for 1870. 
 
 2. 
 
 538, 
 
 " 6th; 
 
 April 25th, 
 
 3. 
 
 839, 
 
 " 17th; 
 
 May 1st, 
 
 4. 
 
 927, 
 
 " 17th; 
 
 April 30th, 
 
 5. 
 
 934, 
 
 " 18th; 
 
 May 1st, 
 
 6. 
 
 1009, 
 
 " 16th; 
 
 April 28th, 
 
 The epochs of 927 and 934 suggest as probable 
 the short period of 7 years. It is found accordingly 
 that the entire interval of 608 years from 401 to 
 1009 is equal to 89 mean periods of 6.8315 years 
 each. With this approximate value the six dates 
 are all represented as follows : 
 
 From A.D. 401 to A.D. 538, 20 periods of 6.85 years. 
 538 to 839, 44 " 6.84 " 
 
 839 to 927, 13 " 6.77 " 
 
 927 to 934, 1 " 7.00 " 
 
 934 to 1009, 11 " 6.82 " 
 
 * Making proper allowance for the precession of the equinoxes. 
 
OTHER METEORIC STREAMS. 93 
 
 This period nearly corresponds to those of sev- 
 eral comets whose aphelion distances are somewhat 
 greater than the mean distance of Jupiter. So long 
 as the cluster occupied but a small arc of the orbit 
 the displays would evidently be separated by con- 
 siderable intervals. The comparative paucity of 
 meteors in modern times may be explained by the 
 fact that the ring has been subject to frequent per- 
 turbations by Jupiter. 
 
 Groups in which the Meteoroids are sparsely scattered. 
 
 By the labors of Heis,Greg,Herschel, Schiaparelli, 
 and others, the radiants of more than fifty sparsely 
 strewn meteor-systems have been determined. Of 
 these the following, which are well defined, seem 
 worthy of special study: 
 
 DATE. POSITION OF RADIANT. 
 
 R. A. N. Decl. 
 
 January 1-4 234 51 
 
 January 18 232 36 
 
 April 25 142 53 
 
 The orbits and periods, except in the few cases 
 previously considered, are entirely unknown. Some 
 of the observed clusters are probably the debris of 
 ancient comets whose aphelia were in the vicinity of 
 Jupiter's orbit. 
 
CHAPTER X. 
 
 THE ORIGIN OF COMETS AND METEORS. 
 
 THE fact that comets and meteors, or at least a 
 large proportion of such bodies, have entered the 
 solar system from stellar space, is now admitted by 
 all astronomers. The question, however, in regard 
 to the origin and nature of these cosmical clouds 
 still remains undecided. The theory that they con- 
 sist of matter expelled with great velocity from the 
 fixed stars appears to harmonize the greatest num- 
 ber of facts, and is accordingly entitled to respect- 
 ful consideration. The evidence by which it is sus- 
 tained may be briefly stated as follows : 
 
 1. The observations of Zollner, Respighi, and 
 others, have indicated the operation of stupendous 
 eruptive forces beneath the solar surface. The rose- 
 colored prominences, which Janssen and Lockyer 
 have shown to be masses of incandescent hydrogen, 
 are regarded by Professor Respighi as phenomena 
 of eruption. *' They are the seat of movements of 
 which no terrestrial phenomenon can afford any 
 idea; masses of matter, the volume of which is 
 many hundred times greater than that of the earth, 
 completely changing their position and form in the 
 space of a few minutes." The nature of this 
 eruptive force is not understood. We may as- 
 sume, however, that it was in active operation 
 94 
 
THE OEIGIN OF COMETS AND METEORS. 95 
 
 long before the sun had contracted to its present 
 dimensions. 
 
 2. With an initial velocity of projection equal to 
 380 miles per second, the matter thrown off from 
 the sun would be carried beyond the limits of the 
 solar system, never to return. With velocities some- 
 what less, it would be transported to distances cor- 
 responding to those of the aphelia of the periodic 
 comets. 
 
 3. On the 7th of September, 1871, Professor 
 Young, of Dartmouth College,* witnessed an extra- 
 ordinary explosion on the sun's surface. The ob- 
 server, with his telescope, followed the expelled 
 matter to an elevation of over 200,000 miles. The 
 mean velocity between the altitudes of 100,000 and 
 200,000 miles was 166 miles per second. This rate 
 of motion in vacuo would indicate an initial velocity 
 of about 260 miles per second. But the sun is sur- 
 rounded by an extensive atmosphere, whose resist- 
 ance must have greatly retarded the velocity of the 
 outrush before reaching the height of 100,000 miles. 
 The original velocity of these hydrogen clouds was 
 therefore sufficient, in all probability, to have car- 
 ried them, if unresisted, beyond the solar domain. 
 Solid or dense matter propelled with equal force 
 would doubtless have been driven off never to re- 
 turn, t 
 
 ^4. This eruptive force, whatever be its nature, is 
 probably common to the sun and the so-called fixed 
 
 * Boston Journal of Chemistry, November, 1871. 
 f See Mr. Proctor's interesting discussion of this subject in the 
 Monthly Notices of the K.A.S., vol. xxxii. 
 
96 COMETS AND METEORS. 
 
 stars. If so, the dispersed fragments of ejected 
 matter ought to be found in the spaces intervening 
 between sidereal systems. Accordingly, the phe- 
 nomena of comets and meteors have demonstrated 
 the existence of such matter, widely diffused, in the 
 portions of space through which the solar system is 
 moving. 
 
 5. According to Mr. Sorby the microscopic struc- 
 ture of the aerolites he has examined points evi- 
 dently to the fact that they have been at one time 
 in a state of fusion from intense heat, a fact in 
 striking harmony with this theory of their origin. 
 
 6. The velocity with which some meteoric bodies 
 have entered the atmosphere has been greater than 
 that which would have been acquired by simply 
 failing toward the sun from any distance, however 
 great. On the theory of their sidereal origin, this 
 excess of velocity has been dependent on the primi- 
 tive force of expulsion. The shower of aerolites 
 which fell at Pultusk, Poland, on the 30th of Janu- 
 ary, 1868,* is not only a remarkable illustration of 
 the fact here stated, but also of another which may 
 be accounted for by the same theory, viz. : that 
 meteoric bodies sometimes enter the solar system in 
 groups or clusters. 
 
 7. A striking argument in favor of this theory 
 may be derived from the researches of the late Pro- 
 fessor Graham, considered in connection with those 
 of Dr. Huggins and other eminent spectroscopists. 
 Professor Graham found large quantities of hydrogen 
 confined in the pores or cavities of certain meteoric 
 
 * See Chapter VII. 
 
THE ORIGIN OF COMETS AND METEORS. 
 
 97 
 
 masses. Now, the spectroscope has shown that the 
 sun's rose-colored prominences consist of immense 
 volumes of incandescent hydrogen ; that the same 
 element exists in great abundance in many of the 
 fixed stars, and even in certain nebulse ; and that 
 the star in the Northern Crown, whose sudden out- 
 burst in 1866 so astonished the scientific world, af- 
 forded decided indications of its presence. 
 
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