A'EROLITE (Gk. 4p, a er, air + 2/Doc, lith o-3, stone), METEORIC STONE, FIREBALL, LITH, OF SHOOTING-STAR. A solid body reaching the earth from unknown points beyond the earth's atmosphere. When seen at night, aerolites usually consist of a luminous head or fireball, followed by a bright train of incandescent matter. Some times there are visible explosions, and even loud detonations are occasionally heard. In the day time the light of both fireball and train is largely lost against the sky background; it is said, how ever, that visible clouds at all times replace the luminous train.
There are numerous records and stories in all ages and countries of the fall of stones from the sky, but until comparatively recent times they were treated by scientific men as instances of popular credulity and superstition. It was not till the beginning of the nineteenth century 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 JEgospo tami, about 407 B.C., is recorded in the Pariah Chronicle (see ARUNDEL MARBLES) , and by Pht tareh and Pliny. It was still shown in the days of Pliny (died 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 pounds fell from the sky near the village of Ensisheim, 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 April 26, 1803. The celebrated French physi cist. AI. Riot. was deputed by the 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 longer been ques tioned. Nearly all the inhabitants of a large district had seen the cloud, heard the noises, and observed the stones fall. Within an ellip tical area of seven miles by three, the number of stones that had fallen could not be less than two or three thousand; the largest were seven teen pounds in weight. These are only a few out of hundreds of instances on record.
As is natural with objects of such mysteri ous origin, meteoric stones have always been regarded with religious veneration. At Emesa,
in Syria, the sun was worshipped under the form of a black stone, reported to have fallen from heaven. The holy Kaaba of Mecca, and the great stone of the pyramid of Cholula, in Mexico, both have a similar history. The exist ence of such bodies once admitted le-d to assign ing 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 Aluseum in St. Petersburg. The largest known is one in Brazil, estimated at 14,000 pounds.
One constant eharacteristie 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 adieu 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 strong ly heated but not incandescent, state when they fall. Their specific gravity ranges from two to seven or eight times that of water. Chemically, the meteoric stones have the saute constitution as our earth, the chief constituent beimg nickel iron, which occurs in variable proportions. No new element has been found in them, and only about twenty-five of those already known. These old elements are often combined in a different manner to form new minerals not yet known in the earth.
Besides these solid masses of eonsiderable size. numerous instances are on record of showers of dust over large tracts of land: and it is remarkable that such dust has generally been found to contain small. hard, angular grains re augite. Stories of the fall of gelatinous masses from the sky are ranked by Humboldt among the mythical fables of meteorology. It has been supposed that such fables may have originated in the very rapid growth of gelatinous alga•, as Nostoc.