The aërolites present an attractive appearance when made into sections, showing crystals and splinterlike fragments, and under the glass seem to be made up of many minute spheres ranging from those the size of a cherry down to others invisible to the naked eye. The minerals prominent in their composition are chrysolite, bronzite, augite, enstatite, feldspar, chronite, etc., showing a marked similarity to the eruptive rocks so well known on the earth. The collections of famous meteorites in the various museums of the world have constantly been examined and studied with a view to determine their origin, the question being a fascinating one to layman and scientist. Astronomers in the past have variously answered the question. The flying fragments were believed by some to be the wreckage of other worlds. Planets had perhaps collided and been rent asunder in former ages, and space filled with the flying fragments. Others thought that meteors were molten matter thrown from the earth or moon. All these theories have been relinquished in view of evidence of a more or less convincing character pointing to the conclusion that the bombardment of the earth is one of the results of the disintegration of comets. In other words, cometary matter flying not always blindly through space, but in the orbit of the comet of which it originally formed a part, constituting the missiles. It is known that the meteors were formed in a region where air and water were absent. It is equally evident that life was not a factor in the past history of the bodies, though it must be acknowledged that the hydrocarbons resembling terrestrial bitumens which are found in some meteorites suggest the possibility of vegetable life. These comets, the mysterious bodies which seem to be roving through space, misconceived planets, as it were, forced into the world half made up, offer the best known solution, as they are literally worlds without air or water, enveloped in a strange and ever-changing substitute for atmosphere; ghostly worlds, which seem to be drawn to the sun, then thrown out into space again to repeat the act until the mighty change from close contact with the fiery mass to the intense cold of distant realms wrecks them, scatters their fragments through the infinity of space where they form gigantic rings or clusters of meteoric matter, raining down upon the sun and planets and all heavenly bodies which meet them, adding fuel to the former, material substance to the latter, and in the case of the moon pitilessly bombarding her crust--illustrating the effect of the bombardment of the earth were it deprived of its atmospheric armor.