Banner of Liberty Middle Town, N.Y. July 6, 1859 Page: 1 Aerolites, or Meteors The following account of Meteors, is from the North American Cyclopedia: AEROLITES, (Gr, aer, air, and lithos, stone) are stones that have fallen from the air. The fact is fully conceded, and it is also established that their composition differs from that of any other substances we are acquainted with. Aerolites have been metwith in almost all parts of the world. One in South America is estimated to weigh 30,000 pounds, and another 14,000 pounds, and there is a large one in the Yale College cabinet from the Red river in Arkansas, which weighs 1,635 pounds. Pallas discovered one in Siberia, which weighed 1,600 pounds, and contains crystals of chyreolite. They are described by Livy, Plutarch and Pliny. The latter speaks of one as large as a wagon, that fell in the Hellespont. By the ancients they were held in great reverence. Iron is the principal ingredient in these stones, varying from 85 to 90 per cent, of their weight; nezt is nickel, from 6.5 to 10.7 per cent., and then follows a long list of metals, which are nearly all found in every analysis, viz: cobalt, copper, tin, magnesium, aluminum, potassium, sodium, manganese, and other substances as sulpher, carbon, silica, phosporus, oxygen and hydrogen. To the metals named lead is now to be added, on the authority of Mr.Gleig, of England, who has discovered it in small globules in a mass of meteoric iron at Tarapaca, Chili. These substances combine to form a number of mineral compounds, some of which are often met with in terrestrial rocks, and one is perculiar to Aerolites. This compound is termed schreibersite, and is phosphuret of iron and nickel, expressed probably by the formula Ni2 Fe4 P. It occurs in small particles and little flakes, disseminated through the mass, and so closely resembles magnetic iron pyrites, that it may easily be mistaken for it. These stones are often called meteoric iron, from the metal of which they are principally composed. In appearance they resemble maleable iron; they are black on the outside and grayish white within, and like iron, affect the magnetic needle. Their specific gravity varies with the relative proportion of metalic and earthy substances. According to Brande and Thompson, it is from 3.35 to 4.28, but according to Dana ("Mineralogy,") it is rarely as low as 6, and a fragment from North Carolina gave 7.318. Van Marum, in the Haarlem Transactions, described one from the Cape of Good Hope of specific gravity - 7.604, which is about the specific gravity of maleable iron. A small one which fell in Tennessee in 1855, has the specific gravity of only 3.2. In whatever part of the world they are found, they present so remarkable a similarity of composition and appearance, that we are compelled to assign to them a common origin. Their composition differing from anything belonging to the earth (though presenting no new elements,) in connection with the circumstances attending their introduction, make it probable that their origin is in some other body than the earth. They appear instantaneously as meteors, surrounded with a bright halo, and rushing through the air in an oblique direction towards the earth with immense velocity. They shine with intense splendor, and then explode with a loud noise, sometimes at the height of thirty or fourty miles above the surface. In Normandy, in France, in the year 1803, they appeared in the form of a ball of fire, accompanied with a small rectangular cloud which did not move, and from which explosions came, the vapor being sent out in all directions on each explosion. This cloud was so high that it appeared at the same instant immediately over the heads of observes a league apart. Stones fell from the cloud with a hissing noise, as if projected with a sling, and were scattered over a tract of country two and a half leagues long by one broad. Above two thousand were collected, the largest weighing seventeen and a half pounds. Fortunately for mankind, the visits of these strangers are seldon in such numbers. They most frequently come singly, and as the unfrequented parts of the earth, and those covered with the waters, present by far the greatest surface, their fall is for the most part remote from the habitations of man. In their fall they bury themselves in the earth, so great is their velocity, and for some time they continue so hot they cannot be handled. As these bodies sometimes illuminate a tract of one hundred or two hundred miles in extent, it is probable that only a portin of the mass reaches the earth, while the main body keeps on its way through the heavens. Three hypotheses have been proposed to account for the source of Aerolites. First, that they are meteors formed in the atmosphere by the aggregation of their particles, as rain and hail are formed. Second, that they belonged to the moon, and were projected from its volcanoes with such force as to bring them within the sphere of the earth's attraction. This is the theory of Laplace. He calculated that a body projected from the moon with the velocity of 1,771 feet in the first second, would reach our earth in about two and a half days. This velocity is less than four times that commonly given to a cannon ball. The third hypothesis is that of Chladoi, the German philosopher, who published his views in a tract at Riga and Leipsic in the year 1794, and still more fully in his great work on this subject published in Vienna in 1819. It is that these bodies are small planets or fragments of planets moving through space, which on entering our atmosphere lose their velocity and fall to the earth. Such considerations lead us to the original hypothesis of Chladoi. As first proposed by him, it is thus stated in general form by Professor Nichol: "Through the interplanetary spaces, and it may be, through the interstellar spaces also, vast numbers of small masses of solid matter may be moving in irregular orbits; and these as they approach any planet of powerful gravitation, such as the earth, will be disturbed and made to fall toward its surface." There is a failure in his hypothesis to account for the heat of these bodues as they pass our atmosphere, and no theory of the compression of the atmosphere caused by their rapid motion has been able to ezplain it. But Professor Nichoi suggests "that the recent and apparently established conception regarding heat, viz: that it must be evolved as an equivalent for any destroyed mechanical effect, wholly removes the difficulty." |
