A'EROLITES (Gr. aer, air, and lithos, stone), or METEORIC STONES, FIREBALLS, and Srtoorixo-srAns: are now classed together as being merely varieties of the same phenomenon. A. that fall during the day arc observed to be projected from a small dark cloud, accompanied by a noise like thunder or the firing of cannon; at night they proceed froni a fireball, which splits into fragments with a similar sound. It is believed that the dark cloud that accompanies the fall of A. by day would be luminous at night; and smoking, exploding fireballs have sometimes been seen luminous even in the brightness of tropical daylight. The connection between A. and fireballs is thus established. Fireballs, again, cannot be separated from shooting-stars, the two pheno mena being sometimes blended, and also being found to merge into one another, both with respect to the size of their disks, the emanation of sparks, and the velocities of their motion.
There are numerous records and stories in all ages and countries of the fall of stones from the sky, but until recent times they were treated by philosophers as instances of popular credulity and superstition. It was not till the beginning of the 19th c. that the fact was established beyond a doubt.—According to Livy, a shower of stones fell on the Alban mount, not far from Rome, about 654 B.C. The fall of a great stone at .2Egospo tami, on the Hellespont, about 467 B.c., is recorded in the Pariah Chronicle (q.v.), and mentioned by Plutarch and Pliny. It was still shown in the days of Pliny (d. 79 .A.D.), who describes it as"the size of a wagon, and of a burned color. In the year 1492 A.D., a ponderous stone, weighing 260 lbs., fell from the sky near the village of Ensisiteim, in Alsace; part of it is still to be seen in the village church. An extraordinary shower of stones fell near L'Aigle, in Normandy, on the 26th April, 1803. The celebrated French philosopher, M. Biot, was deputed by government to repair to the spot and collect the authentic facts; and since the date of his report the reality of such occurrences has no Ionger been questioned. Nearly all the inhabitants of a large district had seen the cloud, heard the noises, and observed the stones fall. Within an elliptical area of seven m. by
three, the number of stones that had fallen could not be less than two or three thousand; the largest were 17 lbs. in weight. These are only a few out of hundreds of instances on record.
As was natural with objects of such mysterious origin, meteoric stones have always been regarded with religious veneration. At Emesa, in Syria, the sun was worshiped under the form of a black stone, reported to have fallen front heaven. The holy Kaaba of Mecca, and the great stone of the pyramid of Cholula, in Mexico, have all the same history.
The existence of such bodies once admitted, led to assigning a meteoric character to strange ferruginous masses found in different countries, and which had no history, or were only adverted to in vague _tradition. Of this kind is the immense mass seen by Pallas in Siberia, now in the imperial museum at St. Petersburg. The largest known is one in Brazil, estimated at 14.000 lbs.
One constant characteristic of meteoric stones is the fused black crust, like varnish, with which the surface is coated. From the circumstance of this coat being very thin, and separated from the inner mass by a sharply defined line, it is thought to indicate some rapid action of heat which has not had time to penetrate into the substance of the stone. This view is favored by the fact that the stones are found in a strongly heated but not incandescent state when they fall. Their specific gravity ranges from two to seven or even eight times that of water.—As to their chemical composition, the predomi nating element is iron, in a native or metallic state, generally combined with a small proportion of nickel. According to Humboldt, the A. that fell in the neighborhood of Agram, in Croatia, in 1751, the Siberian stone, and specimens brought by that philoso pher from Mexico, contain 96 per cent of iron; while in those of Sienna the iron scarcely amounts to 2 per cent, and, in some Taro instances, metallic iron is altogether wanting.