The Theory of Concentric Spheres, supported by arguments drawn from Terrestrial facts; such as the migration of animals to and from the arctic regions, and from refraction, and the variation of the compass, observed in high northern latitudes.

I would now advert to a few of the known terrestrial facts, which have a tendency to support the theory advanced by Captain Symmes; such as the migration of animals, including beasts, birds, and fishes, in the arctic regions; and from refraction, and the variation of the compass observed in high northern latitudes.

It is a fact well attested by whalers and fishers in the northern seas; and one that almost every author who adverts to the northern fisheries confirms, that innumerable and almost incredible numbers of whales, mackerel, herring, and other migratory fish, annually come down in the spring season of the year, from the artic seas towards the equator. Some authors describe the shoals of herring alone, to be equal in surface to the island of Great Britain. Besides these, innumerable shoals of other fish also come down. These fish when they first come from the north in the spring, are in their best plight and fattest condition: but as the season advances, and they move on to the southward, they become poor; so much so, that by the time they get on the coast of France, or Spain, as fishermen say, they are scarce worth catching.

The history of the migratory fish affords strong grounds to conclude, that the shoals which come from the north, are like swarms of bees from the mother hive, never to return; particularly the herring and other small fish. They are not known to return in shoals: and it is doubted by some writers on the subject whether any of them ever return north again, or whether they are not entirely consumed by men, and by other fish.

Whalers and other fishermen who go to the north, generally prosecute their business in the seas between latitudes sixty and seventy degrees, where whales are most abundant. Pinkerton, in his voyages, states, that the Dutch, who at different periods got detained in the ice, and were compelled to winter in high northern latitudes, could find but few fish to subsist on during the winter: which proves that the migrating fish do not winter amongst, or on this side of the ice.—All these facts relative to fish, appear to be well authenticated. Now, were the earth a compact and solid spheroid, according to the old theory; and were the seas frozen nearly to the bottom at the poles, as we would be led to conclude, where could all those fish, that come down to us every spring, breed? or, if they even all returned in the autumn, and all the north were a sea that did not freeze even to the poles, it would require a great stretch of credulity to imagine where they could obtain food for the winter; or even if their source of food were inexhaustible, could the region of the pole afford space sufficient for their health, so as to migrate south in the spring? If the earth be not hollow, (or at least greatly concave about the poles) where could all those fish find room in winter? But on Symmes's plan, admitting the globe to be a hollow sphere, and the inner, or concave part, as habitable as without, (at least as habitable for fish) the whole matter is at once explained.

Whales, and various fish, delight in cold regions. According to Symmes's Theory, a zone at a short distance beyond the real verge of the sphere, (which constitutes the coldest part, or as he has thought proper to term it, "the icy circle,") commencing at the highest point, in about latitude sixty-eight degrees, in the northern sea, near Norway, thence gradually declining to about latitude fifty degrees in the Pacific ocean, which is the lowest point, and thence regularly round again to the highest point. A certain distance beyond this, and short of the apparent verge, this zone, or icy circle exists, which is believed to be the coldest region of the earth. After passing this, we would advance into the interior of the globe, and into a milder clime. In the interior region, it is contended, those immense shoals of fish are propagated and grow, which annually come out and afford us such an abundant supply: nor does it appear that the interior parts of the sphere are altogether forsaken by the fish in summer; for shoals of fat mackerel and herring come down from the north in autumn, as well as in the spring.

The seal, another animal found in cold regions, is also said to migrate north twice each year; going once beyond the icy circle to produce their young; and again to complete their growth, always returning remarkably fat—an evidence that they find something more than snow and ice to feed on in the country to which they migrate.

Numerous other facts of importance, relative to the migration of quadrupeds, are well authenticated by travellers and others: particularly that of the rein-deer. In Rees's Cyclopedia, under the head, "Hudson's Bay," it is stated, that the rein-deer are seen in the spring season of the year, about the month of March or April, coming down from the north, in droves of eight or ten thousand, and that they are known to return northward in the month of October, when the snow becomes deep. Hudson's Bay is situated between sixty and sixty-five degrees north latitude. We are informed by professor Adams of St. Petersburgh, that on the northern coast of Asia, every autumn the rein-deer start north-eastwardly from the river Lena, and return again in the spring, in good condition: the mouth of the river Lena is in about latitude seventy degrees north. This appears to me rather a mystery according to the old theory of the earth, for why should those deer when the cold commences, seek a colder climate, and a more sterile country? The inhospitable coast of Liberia and Hudson's Bay, in the gloom of a dark winter, I should suppose, would be cold enough, without their seeking to spend the winter among nothing but eternal mountains of ice at the pole; where nature must be robed in snows and crowned with storms.

Hearne, who travelled very high north and northwest on the continent of America, details various facts in his journal, which strongly corroborate Symmes's position. Some of the facts he attempts to explain agreeably to his own ideas, and others he considers inexplicable. Among a great collection of facts, he states, that large droves of musk-oxen abound within the arctic circle, few of which ever come so far south as the Hudsons-Bay factories. He mentions seeing in the course of one day, several herds of those animals, of seventy or eighty in a herd, in about latitude sixty-eight degrees. He states that the polar white bears are very rarely found by any of the Indians in winter; and that their winter retreats appear to be unknown;[6] that they are sometimes seen retiring towards the sea on the ice in autumn; and appear again in great numbers in the latter end of March, bringing their young with them.

Hearne also states, that the white or arctic foxes are, some years, remarkably plentiful; and always come from the north; that their numbers almost exceed credibility; that it is well known none of them ever migrate again to the northward; and that naturalists are at a loss to know where they originate.[7] He also mentions that all kinds of game, as well as fish, in those high latitudes, are at some seasons excessively plentiful, and at others extremely scarce.

These facts strongly corroborate the doctrine of a hollow sphere: otherwise, why should the rein-deer, and other animals, migrate north instead of south; as our Buffalo on the plains of Missouri do, when pressed with snow and cold weather? Instinct generally leads animals to fruitful and productive, rather than unproductive, regions; why then proceed north on the approach of winter, unless in expectation of finding a warmer climate, or, at least, a more mild and plentiful country, beyond the icy circle? Independent of the immense droves of rein-deer, great numbers of musk-oxen, white bears, and white foxes, spend their winters towards the north; which tends to establish the fact, that a considerable extent of land must exist in that quarter of the earth. This, however, would infringe on the space necessary to accommodate the vast quantities of fish which appear to be propagated in that region, if the old system were true.

If we were to judge of the internal surface of the sphere, by its animal productions,—admitting that those animals heretofore enumerated, are propagated there,—we should conclude that the internal region of the earth is as much more favourable to the support of animal life, as the rein-deer is larger than our deer, and the white bear larger than our bear; and, consequently, we must conclude that there are more salubrious climates and better countries within, than any we have yet discovered without.

Hearne also informs us that swans, geese, brants, ducks, and other wild water-fowl, are so numerous about Hudson's Bay, in the spring and summer, that the company every season salt up vast quantities of them, sometimes sixty or seventy hogs-heads.[8] He enumerates ten different species of geese, several of which, (particularly the snow geese, the blue geese, brent geese, and horned wavey,) lay their eggs and raise their young in some country unknown, even to the Indians;[9] as their eggs and young are never seen by them, neither have the most accurate observers been able to discover where they make their winter residence; as it is well known that they do not migrate to the southward; but few of them ever pass to the south, and some of the species are said never to have been seen south of latitude fifty-nine degrees.[10] Most of those fowls molt or shed their feathers in a peculiar manner, in summer, and become nearly naked. Hence it would seem that they must breed in winter while absent, for it is impossible that they could lay and sit whilst molting; whereas, the migratory geese and ducks of this country are not known to shed their feathers, in any great degree; and are well known to raise their young in the summer, whilst in the north. It may, therefore, be inferred, that many of those water-fowls, which Hearne describes, raise their young beyond the icy circle and within the sphere. As many of the ten species of geese he saw there, are unknown further south, it establishes the fact, that they do not come to the south to winter.

In the papers of the Honourable D. Barrington, and Colonel Beaufoy, on the possibility of approaching the north pole, read before the Royal Society of London, there is an extensive collection of instances cited, where navigators have reached high northern latitudes; from which it appears to be well authenticated, that navigators have in numerous instances reached the latitude of eighty-two, eighty-three, and eighty-four degrees:[11] and some are said to have sailed as far north as eighty-eight and eighty-nine degrees.[12] It is almost uniformly stated, that in those high latitudes, the sea is clear of ice, or nearly so, and the weather moderate.[13] To cite the various instances in which navigators have sailed far north, would be too tedious:[14] the whole book principally consists of a series of facts, which have a strong bearing on the subject, and to which I would refer the reader who feels disposed to investigate. The whole appears to strengthen the opinion, that there is a barrier, or circle of ice, about where the whalers go to fish; but, when that is passed, we come to an open sea, and a more temperate region.

The sea is stated to be open, and always clear of ice, even in the middle of winter, on the northern part of Spitzbergen, which is situated in latitude eighty degrees north; and the further north the more clear it is of ice.[15] But, at the same season, on the southern parts of Spitzbergen, the sea is bound up with solid and compact ice.

If the doctrine be true, that the earth is a solid spheroid, the cold must increase regularly as we approach the pole, and, consequently, vegetation invariably diminish: this, however, is ascertained not to be the fact. Nova-Zembla, which is situated in north latitude seventy-six degrees, produces no timber, nor even a blade of grass,[16] consequently, all the quadrupeds which frequent it, are foxes and bears; both carniverous animals. On the coast of Greenland, about latitude sixty-five and seventy degrees, neither timber nor grass grows;[17] while on the northern parts of Spitzbergen, they have rein-deer, which are often exceedingly fat; and Mr. Grey mentions three or four species of plants which grow and flower there, during the summer.[18]

On any meridian passing through England, it is ascertained to be more temperate at the latitude of eighty degrees north, than at seventy-three degrees:[19] and both Pinkerton and Barrington inform us, that beyond the latitude of seventy-five degrees, the north winds are frequently warm in winter;[20] that in the middle of winter for several weeks, there falls almost continued rain; and that vegetables and animals are more abundant at the latitude of eighty degrees than at seventy-six degrees.

It has long been observed that the climates vary very considerably on the same parallels of latitude. New York, which is situated in latitude 40 degrees, is known to be considerably colder in the winter than London, which is situated in latitude fifty-five degrees; and the parallel of latitude forty degrees on the plains of Missouri is much colder than the city of New-York. The climate at St. Peters, on the Mississippi, which is in latitude forty-six degrees, is said to be considerably colder than Quebec.[21] This difference of climate has, by some, been attempted to be accounted for, on the principle that land is colder than water, and that the cold is occasioned by the large portion of land in the continent of America: however, I submit to the consideration of the reader, whether so great a difference could arise from a cause of this nature.

In the northern sea, between Spitzbergen and the continent of America, there is a strong current, which always comes from the north, and sets southwardly.[22] It has been stated by some, that, in the spring season of the year, the water of this current is warmer and fresher than the surrounding water of the sea. Various other currents have, at different times, been observed, in different parts of the sea, setting from the north. Floating southwardly on these currents, have been seen large masses of ice, from fresh water rivers, with wolves and bears occasionally on them. New fallen trees have also been seen floating from the north; and various kinds of timber, some of which the species have hitherto been unknown, are frequently found lodged on the northern part of the coast of Norway, having drifted from some region still farther north. Trees have also been found floating in the ocean at latitude eighty degrees; when no timber is known to grow north of latitude seventy degrees. Also, seeds unknown to our botanists, and those of tropical plants have been found drifted on the coast of Norway, and parts adjacent, many of which were in so fresh a state as to vegetate and grow;[23] when it is well known that no plant of their species comes to perfection in any known climate far without the tropics. And, what makes the matter particularly extraordinary, is, that these things appear to be drifted by currents coming from the north; when, according to the old theory, we must believe the sea to be always frozen at the poles, which would render it difficult, if not impossible, to account for the existence of the currents at all.

In the United States of America, and in Europe, the Aurora Borealis is always seen to the north: But many of those travellers and navigators, who penetrated to high northern latitudes, observed the Aurora Borealis in the south, and never in the north. The region in which it is believed to exist, is supposed to be about the place where the verge commences, and about fifty or sixty miles above the plane of the earth's surface; and that the travellers who discovered these appearances south of them, were at that time beyond the verge.

The Indians discovered by Captain Ross, on the coast of Baffin's bay, in the summer of 1818, in latitude seventy-five degrees fifty-five minutes north, when interrogated from whence they came, pointed to the north, where, according to their account, there were "plenty of people;"[24] that it was a warmer country; and that there was much water there. And when Captain Ross informed them that he came from the contrary direction, pointing to the south, they replied, "that could not be, because there was nothing but ice in that direction:"[25] Consequently these people must live in a country not composed of ice; for it appears they deem such an one uninhabitable. Hence we must infer, if the relation given by Captain Ross be correct, that, north of where they then were, the climate becomes more mild, and is habitable; a change, the cause of which is not easily accounted for on the old philosophic principles.

In high northern latitudes, owing to refraction, or some other peculiar circumstance, which hitherto has not, to my knowledge, been attempted to be accounted for, the extent of vision appears to be greatly increased; so that objects, much further than the ordinary distance, are distinctly seen; frequently appearing elevated above the sea, or their real situation; and their image sometimes pictured in the sky. The real objects, themselves, are sometimes seen with the naked eye one hundred and forty or one hundred and fifty miles,[26] and sometimes at the astonishing distance of two hundred miles. These facts are well attested by Captain Ross and other navigators. How this can be accounted for, on the formation maintained by the old theory, I cannot conjecture. I believe it is admitted that the deck of a vessel at sea, any where between the equator and latitude fifty or sixty degrees, cannot be discovered, even by the best telescope, at a greater distance than twelve or fifteen miles.[27] Nay, were there no end to vision, and could the eye penetrate two hundred miles through our atmosphere with sufficient clearness, it would require an observer to be elevated about five miles, before he could discover an object on the surface of the earth two hundred miles distant. But, on the edge of the verge of the polar opening, if the atmosphere were clear, and the power of vision strong enough, an observer might discover objects situated on the verge at any point all round the sphere; as they would be on an exact plane with the observer. And on the contrary, travelling across the verge from the convexity to the concavity of the sphere, a very few miles make objects disappear.

All northern navigators and travellers agree, that high north the sun becomes less bright, and the sky darker, than in more southern latitudes. Is not this owing to the rays of the sun being refracted round the verge of the polar opening? Another circumstance, observed by navigators, who have visited high latitudes is, that the latitude and longitude, as found by celestial observation, frequently differ very materially, sometimes as much as one half, from that given by the log-line.[28] It has also been observed that the mercury in the barometer is less fluctuating in northern regions, than it is further south.

Those appearances observed in the southern hemisphere, which are termed Magellanic clouds, by navigators, have not, so far as I know, been accounted for. They are three in number, of an irregular shape, and observed by night in the South Atlantic, and the south-east parts of the Pacific oceans, (reversed from New-Holland and New-Zealand,) but never visible in the eastern parts of the Indian ocean: their colour is like that of far distant mountains, on which the sun is shining. In the one sea they appear due south, and in the other to the left. They are stationary, appearing perpetually fixed at a certain height, and in a particular situation, as viewed from any given place. The stars and the heavens, in their diurnal revolutions, sweep by them, and they remain the same. To the navigator, who proceeds to the east or west, they appear to be more or less to the right or left of the meridian, in proportion as he changes his longitude; and as he sails south, they increase in height, until they reach the zenith, and finally become north, when seen by an observer south of the straits of Magellan, which is in latitude fifty-two degrees south. Captain Symmes accounts for the appearance of these clouds by the great refractive power of the atmosphere about the polar openings; causing the opposite side of the verge to appear pictured in the sky, as navigators inform us objects do sometimes appear, in the arctic regions; and in the manner Scoresby's ship appeared in the sky, with every particular about her so accurately represented, as to be at once identified by the observers, though the vessel, at that time, was at such a distance as to render it rather incredible how she could be seen at all. As proof of this position, Captain Symmes alleges, that the relative position, shape, and proportions of these clouds, agree in their general outlines with the southern part of New-Zealand, the southeast part of New-Holland, and the whole of Van-Dieman's land, which are situated on, and near to the verge of the sphere, opposite to where the clouds are visible. These clouds are only seen in the night when the atmosphere is clear, at which time the sun is shining on the islands in question. Hence it is alleged, that from these facts, their relative appearance is deducible. As we are never sensible that the rays of light are refracted by the medium through which they pass before they reach our visual organs; we frequently imagine objects to be situated where they really are not; and such is believed to be the case as respects Van-Dieman's and the circumjacent land, as before described.

Franklin, in his journey far north, on the continent of America, discovered a cloud, which appeared to remain always in the same position, and which the Indians informed him was permanent. Not having the book at hand, I cannot now advert particularly to what he says on the subject: but, from memory only, recollect that he states something to that effect. If such an appearance exist there, may it not be accounted for in the same manner as the Magellanic clouds?

Navigators, who have sailed far north, admit the variation of the needle to be excessive. Captain Ross found it in Baffin's Bay, to be as much as one hundred and ten degrees; and Parry, during his voyage in 1822, found it so changed, that the needle pointed within about fourteen degrees of south. All, I believe, concur, that this is a phenomenon which universally occurs in high northern latitudes; but it has hitherto remained unexplained. I believe, according to the old theory, the needle is imagined to be attracted by something at or near the pole: were this supposition correct, the needle would uniformly maintain its polarity on proceeding north, on any given meridian, until you arrived at the very pole itself. The possibility of a moving magnetic cause is difficult, if not impossible, to be reconciled with a solid globe; yet that the magnetic needle does vary on the same meridian, and to a most extraordinary degree, in high northern latitudes, is confirmed beyond all doubt. Why not then urge the variableness of the magnetic cause against the possibility of a solid globe?

According to the doctrine of hollow spheres, this whole mystery, of the variation of the compass, can be satisfactorily explained. The magnetic needle, it is believed, regards the centre of the polar opening, and not the pole or axis of the earth. It will be recollected, that the axis of the earth, being at an angle of twelve or fifteen degrees from the plane of the polar openings, causes one part of the verge to extend farther north than the other, the highest part of which is nearly on a meridian running through Spitzbergen, in about latitude sixty-eight degrees, and the lowermost side in about the fiftieth degree. Now in proceeding north on the first meridian, running near Spitzbergen, there ought to be no variation of the needle until you arrive at the apparent verge, when the needle would cease to traverse; and by proceeding onwards, would turn and point south. Should you proceed north, on a meridian west of this, when you approached the apparent verge, the needle would seem to turn west, but in reality, it would be the meridian turning to the right along the verge to its highest or most northerly point; the needle keeping at a right angle with the verge. And, in like manner, pursuing a course north, on a meridian east of Spitzbergen, on your approach to the apparent verge, the needle would still direct its course at a right angle into the polar opening, (governed, most probably, by some principle of electricity, or other property contained in matter, and kept in one position, subject to the shape of the earth, which may not even yet be exactly known,) the meridian would here wind to the left, and conduct you to the highest point of the apparent verge, north of Spitzbergen. Hence the variation of the needle would be east in Asia, and west in America, which I am told is the fact. From an examination of the variation of the compass, as ascertained in different degrees of latitude and longitude, it increases as you proceed north, and west; which would be exactly the case in accordance with the theory of concentric spheres.[29]

Admitting the earth to be a solid globe, and the cause of magnetism to be some attractive power at the pole, how could the needle vary differently on the same meridian, in different latitudes, at the same period of time, or vary at the same place, at different periods of time? But, admit the doctrine contended for, by the advocates of concentric spheres, and it can be satisfactorily explained. The observations of modern astronomers, have ascertained, that the poles, or axis of the earth, are not always directed to the same fixed star; and, of consequence, that the axis does not always remain parallel to itself. This variation is discovered to be about fifty-one minutes annually; which would make a degree in about seventy-one years: hence the needle always pointing to the polar opening, would vary in about that proportion, at the same place, in the same period of time.[30]