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observers than that distance, if it moved through one hundred degrees of space in a right line nearly, it must have been in view while it was passing through a distance of six or eight hundred miles. Such a calculation would make its speed from forty to sixty miles per second, depending of course upon the accuracy of the estimate of the time. It could not have been describing a curve around Holly Springs, because it was at the same time seen by the observers in Ohio, Pittsburg, Pennsylvania, and Caroline county, Virginia, in its course to the northwest. Mr. Moore, who was at Raleigh, on the opposite side of the meteor's track, and probably about the same distance from it, saw it pass through forty-eight degrees, by measurement, in eight seconds, as he estimated the time it was in view. Its speed, calculated from these data, would approximate fifty miles in a second. As it appeared to be moving in the part of its course seen by me, it seemed certainly not less rapid.
Might not a body moving with this velocity generate a rapid transmission of sound? If we assume that there is some highly elastic medium through which light and electricity, for example, are propagated, might not this body, by the suddenness of the impulse it gave, propagate a sound to a great distance with such speed?
But it may be said that lightning moves with very great velocity, and that yet the noise of the thunder travels with only the speed of other sounds. It is true that, when the flash is near, the thunder seems louder to the ear than any other sound, and yet it is propagated to the distance of only twelve or fifteen miles. On the other hand, though, when one is near a large cannon, its report does not seem so loud as thunder, yet it can be heard to a much greater distance. When, during the late war, I was at Charleston or Savannah, I could, in favorable states of the atmosphere, distinctly hear the guns at the other place, though the two cities are understood to be one hundred miles apart. The cannonades at Charleston were often heard in the upper portions of South Carolina, while those at Richmond, Virginia, were sometimes heard west of Greensboro, in North Carolina-in each case at a distance of nearly one hundred and fifty miles. Why is it, then, that though thunder seems louder than the reports of artillery, it cannot be heard so far?
The explanation does not seem to be difficult. If a pistol be discharged into the water, the bullet breaks the surface violently, and causes the water to be sprinkled for a short distance; but the ripple produced on the surface extends but a few feet around. When, however, the steam-frigate Minnesota was launched at the Washington NavyYard, though she glided so gently into the water that she did not break the surface apparently, yet she caused a wave that extended itself across the harbor, and rose several feet on the shore opposite, wetting many persons who were there to see the launch. As an illustration on a still larger scale, I refer to the fact that earthquakes in Japan cause waves which are propagated across the Pacific Ocean to the shores of California. A large body, though moving slowly, creates a wave which extends to a great distance, while a violent impulse of a small one produces no such result.
From the smallness of the furrow produced by lightning through the bodies of trees struck by it, and from its passing so readily along a small rod, it would seem that the volume of air diplaced by it is small, and
analogous to the effect caused by the pistol-shot on the water; while the explosion of gunpowder, when a large cannon is discharged, produces a greater displacement of the atmosphere, causing a large wave of sound, which is extended to a great distance, as the wave in the water caused by the Minnesota was perceptible for miles.
But, when the ship was launched, though a larger portion of her bulk was in the air than in the water, yet she did not make a corresponding wave in the air which could be felt across the harbor. Even a railroad train, moving much faster than did the Minnesota, does not send in advance of it a great wave in the air. But, in fact, air is capable of receiving such an impulse. When a large gun is discharged, such motion is given to the air that houses are shaken and window glass broken. As air, therefore, is much rarer and more elastic than water, it seems that it requires a much more sudden impulse to create an extended wave in it than in water. If, then, it may be regarded as a general law that the greater the rarity and elasticity of a medium, the more sudden and violent must be a force sufficient to produce a movement that will be extensive, then it might well be that the expansion of gases generated by the explosion of gunpowder would be too slow to affect a medium as much rarer than common air as that air is rarer than water. But a much more sudden and violent movement might possibly cause an impulse in such a medium that could be perceptible at a great distance.
A cannon-ball, propelled with the ordinary charge, is barely driven a mile in five seconds. If we take forty miles per second as the velocity of this meteor, it moved with a speed two hundred times greater than that of the cannon-shot. A spherical cast-iron shot, one foot in diameter, weighs about two hundred and twenty-five pounds. If the meteor be assumed to have had a diameter of one mile, its surface, and the consequent volume of atmosphere displaced, would have been more than twenty-five million times greater than that of the cannon-ball. And, as its solid contents were in bulk more than five thousand times greater than this number indicates, the resistance of the atmosphere would be trifling in comparison with that to the cannon-shot. Even if the diameter of the meteor were but one hundred feet, its surface would have been ten thousand times greater, and its bulk one million times larger. Such a body, moving with a speed two hundred times faster, would present a condition of facts with which we are not at all familiar on the surface of the earth.
The hissing sound described reminds one somewhat of sounds occasionally heard when electricity is passing along imperfect or non-conducting substances.
If electricity be coextensive with the atmosphere, this meteor might have produced great accumulations and disturbances in it, and caused vibrations to great distances. That these should be very rapid would seem to be probable from the fact that the greater the rarity of the several gases the higher the speed with which sound is propagated through
Mr. McEwen, at Athens, heard the hissing sound while the meteor was in sight; but fifteen minutes elapsed before the report from the explosion reached him. The explosion was doubtless caused by the intense heat at the surface of the meteor, which generated gases, the
expansion of which threw off the outer coating of the body in fragments. These gases ought to be expected to expand with a force and speed equal to those caused by the explosion of gunpowder. This has not, I think, been estimated as equalling one mile per second.
Such a movement would, therefore, be slow, compared with the velocity of the meteor itself. Hence, while the hissing sound caused by the latter might move with the rapidity of electricity, that caused by the explosion would travel only with the speed of such sounds as we are familiar with, and would therefore reach a person one hundred and eighty miles distant in fifteen minutes.
HUXLEY, DARWIN AND TYNDALL; OR, THE THEORY OF EVOLUTION.
By Hon. T. L. CLINGMAN.
[Published in the WASHINGTON CHRONICLE, January 31st, 1875.]
So much attention has of late been given to the views of such men of science as Darwin, Huxley, and others, with respect to the origin of life and the production and development of animal and vegetable species, that I am tempted to present to you a paper on this subject. Without claiming more scientific knowledge than any gentleman who reads and reflects may possess, I propose to offer objections to the views of that school of philosophers.
To avoid prolixity I shall abstain from the use of such scientific terms as would require explanation to render them intelligible to many readers, and endeavor simply to state in plain language the propositions of that school, so as to present their views fairly and justly.
Their doctrine may be stated in general terms as embodying the hypothesis that the various species of animals now living were not called into existence by special acts of a creative power, but owe their being and present condition to a slow and gradual development from earlier and inferior animals. It is maintained that all existing species came either from one, or at most a few inferior creatures called monads or primordial forms, and that, by a succession of evolutions or changes in them, all animals exist as we now perceive them. In this mode man himself is supposed to have come from a lower animal, probably of the ape species.
I regard this hypothesis as improbable in itself, without a single fact to support it, and without one plausible argument in its favor.
Let us first consider the theory of "natural selection" or the "survival of the fittest," which is assumed to have been the chief instrumentality that has effected the successive changes that have brought
an animal, originally inferior to the oyster, up to man as he now appears.
By natural selection we are to understand a theory of this kind. The fact is stated that young animals at their birth differ in their constitutions, some of them being larger and stronger than others. During their struggles for existence those having most bodily vigor will survive, while the feeble will succumb to the difficulties with which they are surrounded. As the more vigorous only survive, they transmit to their offspring healthy and strong constitutions. This process being repeated from time to time will not only make the whole species more vigorous than it originally was, but it will acquire new and superior qualities, and will finally seem to have become a different and higher race of animals. This process will be continued, each time producing, by successive evolutions, superior beings, until finally man is formed, his last progenitor having most probably been a species of ape like the ourang-outang or gorilla. The first part of this statement, viz: that among animals those having at birth the most vigorous constitutions survive while the feeble perish, has not the merit of novelty. The fact did not escape the observation of even the most ignorant savages, among whom it is sometimes the custom to expose to death infants so feeble that they would not probably survive and become vigorous adults. Though this practice does not prevail among civilized people, yet one may hear a nurse say that such a new-born infant is so feeble that it will be very difficult "to raise it." Farmers understand this so well that when, in a litter of young pigs, one under size is seen, it is assumed that he will not be able to contend with the others for his food, and it is decided that he must be put in a pen and fed on slops, so that he may, in due time, be killed as a shoat.
All stock raisers recognize this principle, and select their sows and brood mares of good size and fine developments. Unquestionably larger and better animals are thus obtained, but while their size is increased, the improvement does not extend beyond certain limits, which seem invariable for each species. Though the hog can be greatly increased in size, he never becomes as large as the bullock or horse, nor can the horse be gotten up to the bulk of the elephant. There is in fact no evidence of any permanent addition even to the size of the species, much less of any change in its organization. When the stimulating cause ceases the animal seems to revert to its former condition.
Though the Arab and Tartar wild horses have, by good feeding in Europe, been greatly increased in size, yet when left to take care of themselves on the plains of Mexico or South America, they become the smaller mustang, and on the banks of Eastern North Carolina dwindle into the little "marsh pony." In like manner the hog, left to run wild in the mountain forests, is reduced to a small, hardy animal. Even with respect to the human race, which is not subject to changes of food, tall parents often have children shorter than themselves, nor have we any evidence that the process of "evolution or natural selection" has ever produced human beings an hundred or even twenty feet high, as it should have done upon this hypothesis. It seems,
rather, that the changes of which each species is capable, are confined within certain limits easily observed, within which these species seem to vibrate like the pendulum of a clock.
But, even if the fact were otherwise, it would not support the theory of the evolutionists, unless it could also be shown that animals would not only increase in size, but that they could likewise be developed into some other species. It is necessary that the sow should not only become very large, but that she should also produce a cow or a lion, or the mare give birth to a dromedary or an elephant, to lend support to their views.
Great stress is laid on the fact, however, that surrounding conditions do, in certain cases, diminish or influence the development of some animals. It is stated that if a tadpole be kept in cold water he will, for a long period, perhaps an indefinite one, remain simply a tadpole, and not be developed into a frog. This fact, however, is, by no means, a singular one. Every old woman, who raises poultry, knows that if an egg be kept cold it will not hatch, or, to use a scientific phrase, be developed into a chicken. In like manner, all farmers know that if a cold spell of weather comes on immediately after their corn or cotton has been planted, it does not. come up. While this result may be looked for in all cases, there is another analogy between them which is even more unfortunate for the evolutionist. When warm weather causes the seed to germinate, the plant will invariably follow in its form and qualities that from which the seed came. In like manner whenever the egg is hatched the product is a chicken, and never a goose or a rabbit; so, however long the tadpole may be detained in cold water, when he does develop he becomes always a frog. What the advocate of evolution by natural selection needs to show is, that under these conditions the tadpole should become a fish, a lizard, or a mouse. If he could point to such a result as this he would then have one fact to support his hypothesis.
It is said, however, that if we go back to the earliest germs of life, it is difficult, if not impossible, to distinguish those in the eggs of certain birds from such as are found in the eggs of a serpent. But the essential fact remains that, however much alike in appearance they may be, each germ, when developed, invariably produces an animal like that from which it came. This fact makes the case still stronger against the evolutionist; for if it were true that these germs of different animals were in material, form and quality in all respects precisely alike, the great fact that they invariably produce different animals, tends to prove that the form of any particular species is not determined by matter alone, but that the mysterious substance or quality which is designated as vitality, is something independent of the mere identity and form of matter.
When such objections are presented the evolutionists insist that mere negative evidence is insufficient and ought not to be relied on. Though it may be true that negative evidence is inconclusive in some cases, yet in other instances it is as satisfactory and convincing as any positive evidence can be. Suppose an individual were to affirm that a bar of iron, if made red hot, would be converted into gold, I might reply