The Story of the Heavens, Sir Robert Stawell Ball [snow like ashes series TXT] 📗

was discovered by Biela in 1826, and was observed again in 1832. In 1846 the astronomical world was startled to find that there were now two comets in place of one, and the two fragments were again perceived at the return in 1852. In 1859 Biela's comet could not be seen, owing to its unfavourable situation with regard to the earth. No trace of Biela's comet was seen in 1865-66, when its return was also due, nor has it ever been seen since. It therefore appears that in the autumn of 1872 the time had arrived for the return of Biela's comet, and thus the occurrence of the great shower of the Andromedes took place about the time when Biela's comet was actually due. The inference is irresistible that the shooting stars, if not actually a part of the comet itself, are at all events most intimately connected therewith. This shower is also memorable for the telegram sent from Professor Klinkerfues to Mr. Pogson at Madras. The telegram ran as follows:--"Biela touched earth on 27th. Search near Theta Centauri." Pogson did search and did find a comet, but, unfortunately, owing to bad weather he only secured observations of it on two nights. As we require three observations to determine the orbit of a planet or comet, it is not possible to compute the orbit of Pogson's, but it seems almost certain that the latter cannot be identical with either of the two components of Biela's comet. It is, however, likely that it really was a comet moving along the same track as Biela and the meteors.

Another display of the Biela meteors took place in 1885, just giving time for two complete revolutions of the swarm since 1872. The display on the 27th November, 1885, was magnificent; Professor Newton estimated that at the time of maximum the meteors came on at the rate of 75,000 per hour. In 1892 the comet ought again to have returned to perihelion, but in that year no meteors were seen on the 27th November, while many were seen on the 23rd from the same radiant. The change in the point of intersection between the orbit of the meteors and the orbit of the earth indicated by this difference of four days was found by Bredichin to be due to the perturbing action of Jupiter on the motion of the swarm.

It is a noticeable circumstance that the great meteoric showers seem never yet to have projected a missile which has reached the earth's surface. Out of the myriads of Leonids, of Perseids, or of Andromedes, not one particle has ever been seized and identified.[35] Those bodies which fall from the sky to the earth, and which we call meteorites, do not seem to come from the great showers, so far as we know. They may, indeed, have quite a different origin from that of the periodic meteors.

It is somewhat curious that the belief in the celestial origin of meteorites is of modern growth. In ancient times there were, no doubt, rumours of wonderful stones which had fallen down from the heavens to the earth, but these reports seem to have obtained but little credit. They were a century ago regarded as perfectly fabulous, though there was abundant testimony on the subject. Eye-witnesses averred that they had seen the stones fall. The bodies themselves were unlike other objects in the neighbourhood, and cases were even authenticated where men had been killed by these celestial visitors.

No doubt the observations were generally made by ignorant and illiterate persons. The true parts of the record were so mixed up with imaginary additions, that cautious men refused to credit the statements that such objects really fell from the sky. Even at the present day it is often extremely difficult to obtain accurate testimony on such matters. For instance, the fall of a meteorite was observed by a Hindoo in the jungle. The stone was there, its meteoric character was undoubted, and the witness was duly examined as to the details of the occurrence; but he was so frightened by the noise and by the danger he believed himself to have narrowly escaped, that he could tell little or nothing. He felt certain, however, that the meteorite had hunted him for two hours through the jungle before it fell to the earth!

In the year 1794 Chladni published an account of the remarkable mass of iron which the traveller Pallas had discovered in Siberia. It was then for the first time recognised that this object and others similar to it must have had a celestial origin. But even Chladni's reputation and the arguments he brought forward failed to procure universal assent. Shortly afterwards a stone of fifty-six pounds was exhibited in London, which several witnesses declared they had seen fall at Wold Cottage, in Yorkshire, in 1795. This body was subsequently deposited in our national collection, and is now to be seen in the Natural History Museum at South Kensington. The evidence then began to pour in from other quarters; portions of stone from Italy and from Benares were found to be of identical composition with the Yorkshire stone. The incredulity of those who had doubted the celestial origin of these objects began to give way. A careful memoir on the Benares meteorite, by Howard, was published in the "Philosophical Transactions" for 1802, while, as if to complete the demonstration, a great shower of stones took place in the following year at L'Aigle, in Normandy. The French Academy deputed the physicist Biot to visit the locality and make a detailed examination of the circumstances attending this memorable shower. His enquiry removed every trace of doubt, and the meteoric stones have accordingly been transferred from the dominions of geology to those of astronomy. It may be noted that the recognition of the celestial origin of meteorites happens to be simultaneous with the discovery of the first of the minor planets. In each case our knowledge of the solar system has been extended by the addition of numerous minute bodies, which, notwithstanding their insignificant dimensions, are pregnant with information.

When the possibility of stone-falls has been admitted, we can turn to the ancient records, and assign to them the credit they merit, which was withheld for so many centuries. Perhaps the earliest of all these stone-falls which can be said to have much pretension to historical accuracy is that of the shower which Livy describes as having fallen, about the year 654 B.C., on the Alban Mount, near Rome. Among the more modern instances, we may mention one which was authenticated in a very emphatic manner. It occurred in the year 1492 at Ensisheim, in Alsace. The Emperor Maximilian ordered a minute narrative of the circumstances to be drawn up and deposited with the stone in the church. The stone was suspended in the church for three centuries, until in the French Revolution it was carried off to Colmar, and pieces were broken from it, one of which is now in our national collection. Fortunately, this interesting object has been restored to its ancient position in the church at Ensisheim, where it remains an attraction to sight-seers at this day. The account is as follows:--"In the year of the Lord 1492, on the Wednesday before St. Martin's Day, November 7th, a singular miracle occurred, for between eleven o'clock and noon there was a loud clap of thunder and a prolonged confused noise, which was heard at a great distance, and a stone fell from the air in the jurisdiction of Ensisheim which weighed 260 pounds, and the confused noise was at other places much louder than here. Then a boy saw it strike on ploughed ground in the upper field towards the Rhine and the Ill, near the district of Gisgang, which was sown with wheat, and it did no harm, except that it made a hole there; and then they conveyed it from the spot, and many pieces were broken from it, which the Land Vogt forbade. They therefore caused it to be placed in the church, with the intention of suspending it as a miracle, and there came here many people to see this stone, so there were many remarkable conversations about this stone; the learned said they knew not what it was, for it was beyond the ordinary course of nature that such a large stone should smite from the height of the air, but that it was really a miracle from God, for before that time never was anything heard like it, nor seen, nor written. When they found that stone, it had entered into the earth to half the depth of a man's stature, which everybody explained to be the will of God that it should be found, and the noise of it was heard at Lucerne, at Villingen, and at many other places, so loud that the people thought that the houses had been overturned; and as the King Maximilian was here, the Monday after St. Catherine's Day of the same year, his Royal Excellency ordered the stone which had fallen to be brought to the castle, and after having conversed a long time about it with the noblemen, he said that the people of Ensisheim should take it and order it to be hung up in the church, and not to allow anybody to take anything from it. His Excellency, however, took two pieces of it, of which he kept one, and sent the other to Duke Sigismund of Austria, and there was a great deal of talk about the stone, which was suspended in the choir, where it still is, and a great many people came to see it."

Admitting the celestial origin of the meteorites, they surely claim our closest attention. They afford the only direct method we possess of obtaining a knowledge of the materials of bodies exterior to our planet. We can take a meteorite in our hands, we can analyse it, and find the elements of which it is composed. We shall not attempt to enter into any very detailed account of the structure of meteorites; it is rather a matter for the consideration of chemists and mineralogists than for astronomers. A few of the more obvious features will be all that we require. They will serve as a preliminary to the discussion of the probable origin of these bodies.

In the Natural History Museum at South Kensington we may examine a superb collection of meteorites. They have been brought together from all parts of the earth, and vary in size from bodies not much larger than a pin's head up to vast masses weighing many hundredweights. There are also models of celebrated meteorites, of which the originals are dispersed through various other museums.

Many meteorites have nothing very remarkable in their external appearance. If they were met with on the sea beach, they would be passed by without more notice than would be given to any other stone. Yet, what a history a meteorite might tell us if we could only manage to obtain it! It fell; it was seen to fall from the sky; but what was its course anterior to that movement? Where was it 100 years ago, 1,000 years ago? Through what regions of space has it wandered? Why did it never fall before? Why has it actually now fallen? Such are some of the questions which crowd upon us as we ponder over these most interesting bodies. Some of these objects are composed of very characteristic materials; take, for example, one of the more recent arrivals, known as the Rowton siderite. This body differs very much from the more ordinary kind of stony meteorite. It is an object which even a casual passer-by would hardly pass without notice. Its great weight would also attract attention, while if it be scratched or rubbed with a file, it would appear to be a mass of nearly