[footnote] *Humb., 'Rel. Hist.', t. i., p. 519-527. Ellicot in the 'Transactions of the American Society', 1804, vol. vi., . 29. Arago makes the following observations in reference to the November phenomena: "We thus become more and more confirmed in the belief that there exists a zone composed of millions of small bodies, whose orbits cut the plane of the ecliptic at about the point which out Earth annually occupies between the 11th and 13th of November. It is a new planetary world beginning to be revealed to us." ('Annuaire', 1836, p. 296.)
The identity of the epochs was recognized with astonishment. The stream which had been seen from Jamaica to Boston (40 degrees 21' north latitude) to traverse the whole vault of heaven on the 12th and 13th of November, 1833, was again observed in the United States in 1834, on the night between the 13th and 14th of November, although on this latter occasion it showed itself with somewhat less intensity. In Europe the periodicity of the phenomenon has since been manifested with great regularity.
Another and a like regularly recurring phenomenon is that noticed in the month of August, the meteoric stream of St. Lawrence, appearing between the 9th and 14th of August. Muschenbrock,* as early as in the middle of the last century, drew attention to the frequency of meteors in the month of August' but their certain periodic return about the time of St. Lawrence's day was first shown by Quetelet, Olbers, and Benzenberg.
[footnote] *Compare Muschenbroek, 'Introd. ad Phil. Nat.', 1762, t. ii., p. 1061; Howard, 'On the Climate of London', vol. ii., p. 23, observations of the year 1806; seven years, therefore aftr the earliest observations of Brandes (Benzenberg, 'über Sternschnuppen', s. 240-244); the August observations of Thomas Forster, in Quetelet, op. cit., p. 438-453; those of Adolph Erman, Boguslawski, and Kreil, in Schum., 'Jahrb.', 1838, s. 317-330. Regarding the point of origin in Perseus, on the 10th of August, 1839, see the accurate measurements of Bessel and Erman (Schum., 'Astr. Nachr.', No. 385 und 428); but on the 10th of August, 1837, the path does not apper to have been retrograde; see Arago in 'Comptes Rendus', 1837, t. ii., p. 183.
We shall, no doubt, in time, discover other periodically appearing streams,* probably about the 22d to the p. 126 25th of April, between the 6th and 12th of December, and, to judge by the number of true falls of aërolites enumerated by Capocci, also between the 27th and 29th of November, of about the 17th of July.
[footnote] *On the 25th of April, 1095, "innumerable eyes in France saw stars falling from heaven as thickly as hail" ('ut grando, nisi lucerent, pro densitate putaretur'; Baldr., p. 88), and this occurrence was regarded by the Council of Clermont as indicative of the great movement in Christendom. (Wilken, 'Gesch. der Kreuzzüge', bd. i., s. 75.) On the 25th of April, 1800, a great fall of stars was observed in Virginia and Massachusetts; it was "a fire of rockets that lasted two hours." Arago was the first to call attention to the "trainée d'asteroïdes," as a recurring phenomenon. ('Annuaire', 1836, p. 297.) The falls of aërolites in the beginning of the month of December are also deserving of notice. In reference to their periodic recurrence as a meteoric stream, we may mention the early observation of Brandes on the night of the 6th and 7th of December, 1798 (when he counted 2000 falling stars), and very probably the enormous fall of aërolites that occurred at the Rio Assu, near the village of Macao, in the Brazils, on the 11th of December, 1836. (Brandes, 'Unterhalt. für Freunde der Physik', 1825, heft i., s. 65, and 'Comptes Rendus', t. v., p. 211.) Capocci, in the interval between 1809 and 1839, a space of thirty years, has discovered twelve authenticated cases of aërolites occurring between the 27th and 29th of November, besides others on the 13th of November, the 10th of August, and the 17th of July. ('Comptes Rendus', t. xi., p. 357.) It is singular that in the portion of the Earth's path corresponding with the months of January and February, and probably also with March, no 'periodic' streams of falling stars of aërolites have as yet been noticed; although when in the South Sea in the year 1803, I observed on the 15th of March a remarkably large number of falling stars, and they were seen to fall as in a swarm in the city of Quito, shortly before the terrible earthquake of Riobamba on the 4th of February, 1797. From the phenomena hitherto observed, the following epochs seem especially worthy of remark: 22d to the 25th of April. 17th of July (17th to the 26th of July?). (Quet., 'Corr.', 1837, p. 435.) 10th of August. 12th to the 14th of November. 27th to the 29th of November. 6th to the 12th of December. When we consider that the regions of space must be occupied by myriads of comets, we are led by analogy, notwithstanding the differences existing between isolated comets and rings filled with asteroids, to regard the frequency of these meteoric streams with less astonishment than the first consideration of the phenomenon would be likely to excite.
Although the phenomena hitherto observed appear to have been independent of the distance from the pole, the temperature of the air, and other climatic relations, there is, however, one perhaps accidentally coincident phenomenon which must not be wholly disregarded. The Northern Light, the Aurora Borealis, was unusually brilliant on the occurrence of the Borealis, was unusually brilliant on the occurrence of the splendid fall of meteors of the 12th and 13th November, 1833, described by Olmsted. It was also observed at Bremen in 1838, where the periodic meteoric fall was, however, less remarkable than at Richmond, near London. I have mentioned in another work the singular fact observed by Admiral Wrangel, and frequently confirmed to me by himself,* that when he p 127 was on the Siberian coast of the Polar Sea, he observed, during an Aurora Borealis, certain portions of the vault of heaven which were not illuminated, light up and continue luminous whenever a shooting star passed over them.
[footnote] *Ferd. v. Wrangle, 'Reise längs der Nordküste von Sibirien in den Jahren', 1820-1824, th. ii., s. 259. Regarding the recurrence of the denser swarm of the November stream after an interval of thirty-three years, see Olbers, in 'Jahrb.', 1837, s. 280. I was informed in Cumana that shortly before the fearful earthquake of 1766, and consequently thirty-three years (the same interval) before the great fall of stars on the 11th and 12th of November, 1799, a similar fiery manifestation had been observed in the heavens. But it was on the 21st of October, 1766, and not in the beginning of November, that the earthquake occurred. Possibly some traveler in Quito may yet be able to ascertain the day on which the volcano of Cayambe, which is situated there, was for the space of an hour enveloped in falling stars, so that the inhabitants endeavored to appease heaven by religious processions. ('Relat. Hist.', t. i., chap. iv., p 307; chap. x., p. 520 and 527.)
The different meteoric streams, each of which is composed of myriads of small cosmical bodies, probably intersect our Earth's orbit in the same manner as Biela's comet. According to this hypothesis, we may represent to ourselves these asteroid-meteors as composing a closed ring or zone, within which they all pursue one common orbit. The s aller planets between Mars and Jupiter present us if we except Pallas with an analogous relation in their constantly intersecting orbits. As yet, however, we have no certain knowledge as to whether changes in the periods at which the stream becomes visible, or the 'retardations' of the phenomena of which I have already spoken, indicate a regular precession of oscillation of the nodes — that is to say, of the points of intersection of the Earth's orbit and of that of the ring; or whether this ring or zone attains so considerable a degree of breadth from the irregular grouping and distances apart of the small bodies, that it requires several days for the Earth to traverse it. The system of Saturn's satellites shows us likewise a group of immense width, composed of most intimately-connected cosmical bodies. In this system, the orbit of the outermost (the seventh) satellite has such a vast diameter, that the Earth, in her revolution round the Sun, requires three days to traverse an extent of space equal to this diameter. If, therefore, in one of these rings, which we regard as the orbit of a periodical stream, the asteroids should be so irregularly distributed as to consist of but few groups sufficiently dense to give rise to these phenomena, we may easily understand why we so seldom witness such glorious spectacles as those exhibited in the November months of 1799 and 1833. The acute mind of Olbers led him almost to predict that the next appearance of the phenomenon of shooting stars and fire-balls intermixed, falling like flakes of snow, would not recur until between the 12th and 14th of November, 1867.
p 128 The stream of the November asteroids has occasionally only been visible in a small section of the Earth. Thus, for instance, a very splendid 'meteoric shower' was seen in England in the year 1837, while a most attentive and skillful observer at Braunsberg, in Prussia only saw on the same night, which was there uninterruptedly clear, a few sporadic shooting stars fall between seven o'clock in the evening and sunrise the next morning. Bessel* concluded from this "that a dense group of the bodies composing the great ring may have reached that part of the Earth in which England is situated, while the more eastern districts of the Earth might be passing at the time through a part of the meteoric ring proportionally less densely studded with bodies."