Arizona Sketches

by J. A. Munk

"Still another contribution to the subject, while it does not increase the number of hypotheses, is nevertheless important in that it tends to diminish the weight of the magnetic evidence and thus to reopen the question which Mr. Baker and I supposed we had settled. Our fellow-member, Mr. Edwin E. Howell, through whose hands much of the meteoric iron had passed, points out that each of the iron masses, great and small, is in itself a complete individual. They have none of the characters that would be found if they had been broken one from another, and yet, as they are all of one type and all reached the earth within a small district, it must be supposed that they were originally connected in some way.

"Reasoning by analogy from the characters of other meteoric bodies, he infers that the irons were all included in a large mass of some different material, either crystalline rock, such as constitutes the class of meteorites called 'stony,' or else a compound of iron and sulphur, similar to certain nodules discovered inside the iron masses when sawn in two. Neither of these materials is so enduring as iron, and the fact that they are not now found on the plain does not prove their original absence. Moreover, the plain is strewn in the vicinity of the crater with bits of limonite, a mineral frequently produced by the action of air and water on iron sulphides, and this material is much more abundant than the iron. If it be true that the iron masses were thus imbedded, like plums in an astral pudding, the hypothetic buried star might have great size and yet only small power to attract the magnetic needle. Mr. Howell also proposes a qualification of the test by volumes, suggesting that some of the rocks beneath the buried star might have been condensed by the shock so as to occupy less space.

"These considerations are eminently pertinent to the study of the crater and will find appropriate place in any comprehensive discussion of its origin; but the fact which is peculiarly worthy of note at the present time is their ability to unsettle a conclusion that was beginning to feel itself secure. This illustrates the tentative nature not only of the hypotheses of science, but of what science calls its results.

"The method of hypotheses, and that method is the method of science, founds its explanations of nature wholly on observed facts, and its results are ever subject to the limitations imposed by imperfect observation. However grand, however widely accepted, however useful its conclusions, none is so sure that it cannot be called into question by a newly discovered fact. In the domain of the world's knowledge there is no infallibility."

After Prof. Gilbert had finished his experiments, Mr. Volz tried some of his own along the same line. He found upon trial that the meteorites in his possession were non-magnetic, or, practically so. If these, being pieces of the larger meteorite which was buried in the hole, were non-magnetic, all of it must be non-magnetic, which would account for the failure of the needle to act or manifest any magnetic attraction in the greater test.

Mr. Volz also made another interesting discovery in this same connection. All over the meteorite zone are scattered about small pieces of iron which he calls "iron shale." It is analogous to the true meteorite, but is "burnt" or "dead." He regards these bits of iron as dead sparks from a celestial forge, which fell from the meteorite as it blazed through the heavens.

In experimenting with the stuff he found that it was not only highly magnetic, but also possessed polarity in a marked degree; and was entirely different from the true meteorite. Here was a curiosity, indeed; a small, insignificant and unattractive stone possessed of strong magnetic polarity, a property of electricity that is as mysterious and incomprehensible as is electricity itself.

Another peculiarity of Canon Diablo meteorite is that it contains diamonds. When the meteorite was first discovered by a Mexican sheep herder he supposed that he had found a large piece of silver, because of its great weight and luster, but he was soon informed of his mistake. Not long afterwards a white prospector who heard of the discovery undertook to use it to his own advantage, by claiming that he had found a mine of pure iron, which he offered for sale. In an attempt to dispose of the property samples of the ore were sent east for investigation. Some of the stone fell into the hands of Dr. Foote, who pronounced it to be meteorite and of celestial origin.

Sir William Crookes in discussing the theory of the meteoric origin of diamonds[2] says "the most striking confirmation of the meteoric theory comes from Arizona. Here, on a broad open plain, over an area about five miles in diameter, were scattered from one to two thousand masses of metallic iron, the fragments varying in weight from half a ton to a fraction of an ounce. There is little doubt that these masses formed part of a meteorite shower, although no record exists as to when the fall took place. Curiously enough, near the center, where most of the meteoritics have been found, is a crater with raised edges three quarters of a mile in diameter and about six hundred feet deep, bearing exactly the appearance which would be produced had a mighty mass of iron or falling star struck the ground, scattering in all directions, and buried itself deep under the surface. Altogether ten tons of this iron have been collected, and specimens of Canyon Diablo Meteorite are in most collectors' cabinets.

"An ardent mineralogist, the late Dr. Foote, in cutting a section of this meteorite, found the tools were injured by something vastly harder than metallic iron, and an emery wheel used in grinding the iron had been ruined. He examined the specimen chemically, and soon after announced to the scientific world that the Canyon Diablo Meteorite contained black and transparent diamonds. This startling discovery was afterwards verified by Professors Friedel and Moissan, who found that the Canyon Diablo Meteorite contained the three varieties of carbon--diamond (transparent and black), graphite and amorphous carbon. Since this revelation the search for diamonds in meteorites has occupied the attention of chemists all over the world.