Comets and Meteors Part 5

(12.) 1650, _March_ 30.--A Franciscan monk was killed at Milan by the fall of a meteoric stone.

(13.) 1674.--Two Swedish sailors were killed on s.h.i.+pboard by the fall of an aerolite.

(14.) 1751, _May_ 26.--Two meteoric ma.s.ses, consisting 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 Bordeaux, France. Over Barbotan a loud explosion was heard, which was followed by a shower of meteoric stones of various magnitudes.

(16.) 1794, _July_.--A fall of about a dozen aerolites occurred at Sienna, Tuscany.

(17.) 1795, _December_ 13.--A large meteoric stone fell near Wold Cottage, in Yorks.h.i.+re, England. "Several persons heard the report of an explosion 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 toward 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 considerable district."--_Milner's 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 P.M., the heavens being almost cloudless, a tremendous noise, like that of thunder, was heard, and at the same time an immense fire-ball was seen moving 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, generally penetrating to some distance beneath the surface. Nearly 3000 of these fragments were found and collected, the largest weighing about 17 pounds. The occurrence very naturally excited great attention. M. Biot, under the authority of the government, repaired to the place, collected the various facts in regard to the phenomenon, took the testimony of witnesses, etc., and finally embraced the results of his investigations in an elaborate memoir.

(20.) 1807, _December_ 14.--A large meteor exploded over Weston, Connecticut. The height, direction, velocity and magnitude of this body were discussed by Dr. Bowditch in a memoir communicated 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 disappearance 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 between the fingers. On exposure to the air, however, 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 suns.h.i.+ne, 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 Professor Loomis, may be found in the _American Journal 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 Was.h.i.+ngton and n.o.ble counties, and the prolongation of its projection, on the earth's surface, pa.s.ses directly through New Concord, in the southeast corner of Muskingum county. The meteor when first seen was about 40 miles from the earth's surface. The sky, at the time, was for the most part covered with clouds over northwestern Ohio, so that if any portion of the meteoric ma.s.s 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 absolute velocity in the solar system must have been somewhat greater than that of the earth.

"At New Concord,[21] 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 seconds, another similar report. After two or three seconds another, and so on with diminis.h.i.+ng intervals. Twenty-three distinct detonations were heard, after which the sounds became 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 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."

[21] New Concord is close to the Guernsey county line. Nearly all the stones fell in Guernsey.

Over thirty of the stones which fell were discovered, while doubtless many, especially of the smaller, being deeply buried beneath the soil, entirely escaped 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 specimens, 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, which were followed by showers of meteoric stones near the villages of Orgueil and Nohic. The princ.i.p.al 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...o...b..tal motion.

"This example," says Professor Newton, "affords the strongest proof that the detonating and stone-producing meteors are phenomena not essentially unlike."

(25.) 1868, _January_ 30.--It is obviously a matter of much importance that the composition and general characteristics of aerolites, together with the phenomena attending their fall, should be carefully noted; as such facts have a direct bearing on the theory of their origin. In this regard the memoirs of Professors J. G. Galle, of Breslau, and G. vom Rath, of Bonn, on a meteoric fall which occurred at Pultusk, Poland, on the 30th of January, 1868, have more than ordinary interest. These memoirs establish the fact that the aerolites of the Pultusk shower _entered our atmosphere_ as a swarm or cl.u.s.ter of distinct meteoric ma.s.ses. 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 4-1/2 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 ma.s.ses have been found so closely similar in structure to aerolites whose descent has been witnessed, as to leave no doubt in regard to their origin. One of these is a ma.s.s 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 ma.s.s 7-1/2 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 removed and deposited in one of the rooms of the British Museum. A similar block, of meteoric origin, weighing more than six tons, was discovered some years since in the province of Bahia, in Brazil.

GENERAL REMARKS.

1. A Committee on Luminous Meteors was appointed several years since by the British a.s.sociation for the Advancement of Science. This committee, consisting at present of James Glaisher, F.R.S., Robert P. Greg, F.R.S., Alexander S. Herschel, F.R.A.S., and Charles Brooke, F.R.S., report from year to year not only their own observations on aerolites, fire-b.a.l.l.s, and falling stars, but also such facts bearing upon the subject as can be derived from other sources. An a.n.a.lysis 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 following:

(_a._) January 4th.

(_b._) " 16th.

(_c._) " 29th.

(_d._) February 10th.

(_e._) " 15th--18th.

(_f._) March 6th.

(_g._) " 12th.

(_h._) April 1st.

(_i._) " 10th--14th.

(_j._) May 8th--9th.

(_k._) " 13th--14th.

(_l._) " 17th--19th.

(_m._) June 3d.

(_n._) " 9th.

(_o._) " 12th.

(_p._) " 16th.

(_q._) July 3d--4th.

(_r._) " 14th--17th.

(_s._) August 5th--7th.

(_t._) " 11th.

(_u._) September 4th--10th.

(_v._) October 13th.

(_w._) November 5th.

(_x._) " 12th--13th.

(_y._) " 27th--30th.

(_z._) December 5th.

(_z'._) " 8th--14th.

(_z"._) " 27th.

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 elementary 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 planetary bodies, like all the larger or smaller agglomerated ma.s.ses 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. .h.i.therto observed in meteoric stones, iron is found in the greatest abundance. The specific gravities vary from 1.94 to 7.901: the former being that of the stone of Alais; the latter that of the meteorite of Wayne county, Ohio, described by Professor J. L. Smith in _Silliman's Journal_ for November, 1864, p.

385.

5. The average number of aerolitic falls in a year was estimated by Schreibers at 700. Baron Reichenbach, 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 magnitude, from a weight of less than a single ounce to over fifteen tons. The baron even suspects the meteoric origin of large ma.s.ses of dolerite which all former geologists had considered native to our planet.

6. An a.n.a.lysis of any extensive table of meteorites and fire-b.a.l.l.s proves that a greater number of aerolitic falls have been observed during the months of June and July, when the earth is near its aphelion, than in December and January, when near its perihelion. It is found, however, that the reverse is true in regard to bolides, or fire-b.a.l.l.s.

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 numbers of aerolitic falls. On the other hand, it is obvious that fire-b.a.l.l.s, 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.

CHAPTER VIII.

SHOOTING-STARS.--METEORS OF NOVEMBER 14.

Although shooting-stars have doubtless been observed 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 observed from the West Indies to British America, and from 60 to 100 west longitude from Greenwich. As early as 10 o'clock on the evening of the 12th shooting-stars were observed with unusual frequency; their motions being generally westward. Soon after midnight their numbers became so extraordinary as to attract the attention of all who happened to be in the open air. The meteors, however, 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.