IV. METEORITES.
The nineteenth century will be forever memorable for its witnessing the closing career and final destruction of a famous comet. First noticed in France, in 1772, and rediscovered, in 1826, by an Austrian officer named Biela, it bears his name. His computation showed that it traversed its orbit in six and one half years. When it reappeared in 1846, and again in 1852, it was seen to have split into two unequal fragments. It has not been seen since; but at every time when its return should have taken place the earth has passed through showers of meteors supposed to be its constituent particles, and to indicate its entire disintegration.
During the meteoric shower of 1885, on the 27th of November, a large iron meteorite fell in Mazapil, Mexico, and chemical and physical investigation joined to pronounce it a part of the lost Biela’s comet.
The large cabinets of the world contain hundreds of specimens of meteorites, known to be such by their chemical composition, but only a few have actually been seen to fall. The most remarkable fall ever witnessed was that of May 10, 1879, in Iowa, in which the heaviest stone weighed 437 pounds. On April 8, 1893, an aerolite fell near Osawatomie, Kansas, and struck the monument to John Brown that had been erected through the efforts of Horace Greeley in 1863. The meteor broke off the left arm of the statue. A Texas meteorite, owned by Yale University, weighs 1635 pounds. A meteorite that fell in Jiminez, in 1892, now deposited in the city of Mexico, weighs twenty tons; and one lying on the coast of Labrador, which it is proposed to bring to the United States, is said to be still more massive.
V. DO METEORS OFTEN STRIKE THE EARTH?
It must not be thought that meteors usually strike the earth. In truth, but few of them do. The earth is surrounded by them, cold, dark, invisible, because unillumined. It is only when they become heated by rapidly impinging on the atmosphere that they can be seen at all; and unless they come near enough to become subject to the dominant power of the earth’s attraction, they pass off into space unnoticed, and their presence unsuspected.
JAMES H. COFFIN,
Late Professor of Astronomy, Lafayette College, Easton, Pa.
A case in point is the brilliant “fire-ball” of July 20, 1860, that moved rapidly over the United States, from Wisconsin to Cape Cod, and then passed off into the skies. The entire time of its visible flight over a path of thirteen hundred miles was about two minutes. It was seen about ten o’clock in the evening. It was estimated to be from one hundred to five hundred feet in diameter, allowing for an increase as it expanded by reason of its striking with such velocity the lower and denser layers of the air. Its size and brilliancy were such as to arrest the attention of hundreds of persons, some of whom crouched in fear, and even alleged that they heard it hiss as it flew over their heads. Some fishermen in Lake Huron had ropes over the sides of their boat, ready to spring into the water if it came too near.