In the case of the fall of meteoric stones, which occasionally occur, it has sometimes been noticed that the sound caused by the explosion of the meteorite, or its passage through the air, is heard before the meteorite is seen to fall. This has been explained by the fact that owing to the resistance of the air to a body moving at first with a high velocity its speed is so reduced that it strikes the earth with a velocity less than that of sound. Hence the sound reaches the earth before the body strikes the ground.[236]
The largest meteoric stone preserved in a museum is that known as the Anighita, which weighs 36½ tons, and was found at Cape York in Greenland. It was brought to the American Museum of Natural History by Commander R. E. Peary, the Arctic explorer.
The second largest known is that of Bacubirito in Mexico, the weight of which is estimated at 27½ tons.
The third largest is that known as the Williamette, which was found in 1902 near the town of that name in Western Oregon (U.S.A.). It is composed of metallic nickel-iron, and weighs about 13½ tons. It is now in the American Museum of Natural History.
A large meteorite was actually seen, from the deck of the steamer African Prince, to fall into the Atlantic Ocean, on October 7, 1906! The captain of the vessel, Captain Anderson, describes it as having a train of light resembling “an immense broad electric-coloured band, gradually turning to orange, and then to the colour of molten metal. When the meteor came into the denser atmosphere close to the earth, it appeared, as nearly as is possible to describe it, like a molten mass of metal being poured out. It entered the water with a hissing noise close to the ship.”[237] This was a very curious and perhaps unique phenomenon, and it would seem that the vessel had a narrow escape from destruction.
In Central Arizona (U.S.A.) there is a hill called Coon Butte, or Coon Mountain. This so-called “mountain” rises to a height of only 130 to 160 feet above the surrounding plain, and has on its top a crater of 530 to 560 feet deep; the bottom of the crater—which is dry—being thus 400 feet below the level of the surrounding country. This so-called “crater” is almost circular and nearly three-quarters of a mile in diameter. It has been suggested that this “crater” was formed by the fall of an enormous iron meteorite, or small asteroid. The “crater” has been carefully examined by a geologist and a physicist. From the evidence and facts found, the geologist (Mr. Barringer) states that “they do not leave, in my mind, a scintilla of doubt that this mountain and its crater were produced by the impact of a huge meteorite or small asteroid.” The physicist (Mr. Tilghmann) says that he “is justified, under due reserve as to subsequently developed facts, in announcing that the formation at this locality is due to the impact of a meteor of enormous and unprecedented size.” There are numerous masses of meteoric iron in the vicinity of the “crater.” The so-called Canyon Diabolo meteorite was found in a canyon of that name about 2½ miles from the Coon Mountain. The investigators estimate that the great meteoric fall took place “not more than 5000 years ago, perhaps much less.” Cedar trees about 700 years old are now growing on the rim of the mountain. From the results of artillery experiments, Mr. Gilbert finds that “a spherical projectile striking solid limestone with a velocity of 1800 feet a second will penetrate to a depth of something less than two diameters,” and from this Mr. L. Fletcher concludes “that a meteorite of large size would not be prevented by the earth’s atmosphere from having a penetration effect sufficient for the production of such a crater.”[238]
The meteoric origin of this remarkable “crater” is strongly favoured by Mr. G. P. Merrill, Head Curator of Geology, U.S. National Museum.
The Canyon Diabolo meteorite above referred to was found to contain diamonds! some black, others transparent. So some have said that “the diamond is a gift from Heaven,” conveyed to earth in meteoric showers.[239] But diamond-bearing meteorites would seem to be rather a freak of nature. It does not follow that all diamonds had their origin in meteoric stones. The mineral known as periodot is frequently found in meteoric stones, but it is also a constituent of terrestrial rocks.
In the year 1882 it was stated by Dr. Halm and Dr. Weinhand that they had found fossil sponges, corals, and crinoids in meteoric stones! Dr. Weinhand thought he had actually determined three genera![240] But this startling result was flatly contradicted by Carl Vogt, who stated that the supposed fossils are merely crystalline conformations.[241]
Some meteorites contain a large quantity of occluded gases, hydrogen, helium, and carbon oxides. It is stated that Dr. Odling once “lighted up the theatre of the Royal Institution with gas brought down from interstellar space by meteorites”![242]