Symmes's Theory of Concentric Spheres. James McBrideЧитать онлайн книгу.
goes to prove that air presses equally in all directions. Not a single experiment in this branch of natural science can be performed that does not depend on such a property. This being the case, if the boundless extent of the universe, beyond the limits of our atmosphere, be an entire vacuum, why should the atmosphere be retained in its present circumscribed form, and not expand, by virtue of its repellant quality, far beyond its known height? To prevent this, Symmes believes universal space to be filled with an elastic fluid, inconceivably rare, and uniformly distributed throughout; differing from common air, and from the elastic fluids (which also are known to be repellant) existing in our atmosphere. This tendency is what Symmes believes should be understood by the term gravity; the laws of action governing which he holds to be true, as defined by Newton: and he moreover holds that the application of the laws of gravity, as laid down by Newton, leads a reasoning mind to the belief of concentric spheres, with open poles, as all planetary bodies are in his opinion formed.
In regard to the effects of gravity, he pretends not to differ from the generally received opinion of the age; but the application of them, as to the inner parts of insulated bodies, has enabled him to improve in a knowledge of the formation of planets; and finally led him to form a correct idea of what constitutes gravity.
The author of the new theory entertains a belief that the principles of planetary orbicular forms, developed by him, extend as well to the molecules of the most subtile fluids, as to the innumerable stars or suns of the universe, and all their planetary trains: he contends that though he may not have discovered any new principles in physics, yet that he has made interesting advances in a knowledge of the application of what was heretofore known.
According to him, the planet which has been designated the Earth, is composed of at least five hollow concentric spheres, with spaces between each, an atmosphere surrounding each; and habitable as well upon the concave as the convex surface. Each of these spheres are widely open at their poles. The north polar opening of the sphere we inhabit, is believed to be about four thousand miles in diameter, and the southern above six thousand.[1] The planes of these polar openings are inclined to the plane of the ecliptic at an angle of about twenty degrees; so that the real axis of the earth, being perpendicular to the plane of the equator, will form an angle of twelve degrees with a line passing through the sphere at right angles with the plane of the polar openings; consequently the verge of the polar openings must approach several degrees nearer to the equator on one side than on the other. The highest north point, or where the distance is greatest from the equator to the verge of the opening in the northern hemisphere, will be found either in the northern sea, near the coast of Lapland, on a meridian passing through Spitsbergen, in about latitude sixty-eight degrees, or somewhat more eastwardly in Lapland; and the verge would become apparent, to the navigator proceeding north, in about latitude ninety degrees.
The lowermost point, or the place where the distance is least from the equator to the verge of the northern polar opening, will be found in the Pacific ocean, about latitude fifty degrees, near the north-west coast of America, on or near a meridian running through the mouth of Cook's river, being in about one hundred and sixty degrees west longitude, the real verge being in about latitude fifty degrees and becoming apparent to a person travelling northward at right angles with the magnetic equator, at the distance of about twelve hundred miles further. The verge varies progressively from the lowest to the highest point, crossing the north-west coast of America between latitude fifty-two and fifty-four, thence across the continent of North America, passing through Hudson's Bay and Greenland, near cape Farewell; thence by mount Hecla to the highest point; thence tending gradually more to the south, across the northern parts of Asia, at or near the volcanoes of Kamtschatka, and along the extinguished volcanoes of the Fox Islands, to the lowermost point again, near the northwest coast.
In the southern hemisphere, the highest point, or place where the distance is greatest from the equator to the verge of the polar opening, will be found in the southern Pacific ocean, in about latitude forty-six degrees south, and perhaps about longitude one hundred and thirty degrees west; and the lowermost point, or place where the distance is least from the equator to the verge of the opening, will be found on a meridian south or south-east of the island of Madagascar, in about latitude thirty-four degrees south, and longitude about fifty degrees east; thence passing near the cape of Good Hope, across the Atlantic ocean, and southern part of the continent of America, through a chain of active volcanoes, to the highest point; thence bearing regularly toward the lowest point, passing between the two islands of New-Zealand, or across the most southerly one, and the northernmost part of Van Dieman's land, to the lowest point, which is south or south-east of Madagascar; the apparent verge being several hundred miles beyond the real verge.[2] Consequently, according to this formation of the sphere, the degrees of latitude, on different meridians, will vary according to their distance from the polar openings; and the magnetical equator, which encircles the sphere, parallel to the plane of the polar openings, would cut the real equator at an angle of twelve degrees. A person standing on the highest part of the apparent verge would appear to be under the polar star, or nearly so, and at the ninetieth degree of latitude. The meridians all converge to the highest point of the verge, or the ninetieth degree; consequently, in tracing a meridian of longitude, you would pursue a direction at right angles to the equator, until you arrived in the neighbourhood of the real verge of the polar opening, when the meridians would change their direction and turn along between the real and apparent verges towards the highest point, until they all terminated at the ninetieth degree of latitude; this being the direction a person would travel in order to have his back to the sun always at 12 o'clock, the time of his greatest altitude. Although the particular location of the places where the verges of the polar openings are believed to exist, may not have been ascertained with absolute certainty, yet they are believed to be nearly correct; their localities having been ascertained from appearances that exist in those regions; such as a belt or zone surrounding the globe where trees and other vegetation (except moss) do not grow; the tides of the ocean flowing in different directions, and appearing to meet; the existence of volcanoes; the "ground swells" in the sea being more frequent; the Aurora Borealis appearing to the southward; and various other phenomena existing in and about the same regions, mark the relative position of the real verges.
The heat and cold of the different climates are governed by their distance from the verge of the polar opening, and do not depend on their nearness to or remoteness from the equator. The natural climates are parallel to the planes of the polar openings, and cut the parallels of latitude at an angle of twelve degrees. When the sun is on the tropic of Capricorn, the circle of greatest cold would be about twenty-three and a half degrees south of the apparent verge, and when the sun is on the tropic of Cancer this circle would probably be just under the umbrage of the real verge: hence it follows, if this doctrine be correct, that the climate of forty degrees north latitude on the plains of Missouri, in the western part of the continent of America, will be as cold in winter, as the latitude of fifty or fifty-two degrees in Europe; and observation has fully confirmed such to be the fact.
The magnetic principle which gives polarity to the needle, is believed to be regulated by the polar openings, and that the needle always points directly to the opening, and of course parallel to a line drawn perpendicular to the plane of the opening. And when the apparent verge shall be passed, the needle will seem to turn nearly round, so as to point in an opposite direction; having the contrary end north on the interior of the sphere, that was north on the exterior, the same end being north on the interior which was south on the exterior. Hence, when navigators arrive in the neighbourhood of the apparent verge, the variation of the needle becomes extreme; and when the verge is passed, the variation is more or less reversed. The meridians run from the highest northern to the highest southern point on the verges; hence, in tracing a meridian, or sailing due north, we would pursue that line which would conduct us directly from the sun at his greatest altitude; and when we come to the verge, the meridian would vary, and wind along the vicinity of the edge of the real verge, until it brought us to the highest point of the apparent verge. The magnetic needle, on arriving at the verge would appear to cease to pursue the same direction, but would in reality continue to maintain it, and lead directly into the polar opening.
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