REFLECTIONS ON THE ORIGIN AND FORMATION OF THE ISLAND.
THE appearance of a volcanic island in the middle of the ocean, so far removed from any other land, is an object that excites curiosity and attention. It has been supposed by some geologists, that such islands are never produced far out at sea, or in situations unconnected with other shores. But here we have an example of the contrary, in an island, which, from its distance, cannot be supposed to have any connection with the shores of other lands; and which has been raised by some extraordinary effort of Nature, from the bottom of a vast unfathomable ocean. Its remote and solitary situation, and the wildness and singularity of its whole aspect, naturally suggest some reflections on the probable circumstances of its origin and formation. But however natural and interesting such reflections may be to the human mind, great difficulty and uncertainty must always attend our inquiries into those remote and mysterious processes of nature, which lye beyond the reach of our observation and experience. The formation of the great strata of the globe, the production of mountains, and the emersion of islands from the bottom of the sea, are operations which, as we have never had an opportunity of seeing them actually take place, we can only reason about from present appearances; and we can in this way at last only arrive at conclusions, which, from the imperfection of our knowledge, do not admit of the clearest and most satisfactory evidence. From the various, opposite, and contradictory views of things, into which, even men of science and observation have been led, in their reasonings concerning the structure of the globe, it should seem that Nature, in the manner of accomplishing her great terraqueous revolutions, has hitherto mocked the imbecility of human research.
Yet some of these ingenious theories, which aim at explaining the changes that have taken place in the constitution of the globe, are valuable, on account of the many beautiful and interesting views of Nature which they exhibit; and even the most improbable of them have not entirely been without their use, as they have indirectly contributed to the advancement of knowledge: For men seldom labour so assiduously in comparing and investigating facts, as when they have some favourite hypothesis to support; and the meteors of theory, although they cannot dispel the darkness of the hemisphere, may yet incidentally discover some latent paths and recesses in the labyrinth of Nature. In this way, many important facts have been brought to light, which might otherwise have lain concealed; and ardent minds, while intent on the pursuit of some extravagant phantom, have frequently hit upon the discovery of useful truths. Considerable advances have accordingly been made in examining those parts of the globe, which lye open to investigation; though many facts are still wanting, and probably the accumulated knowledge of ages may be required to enable philosophers to frame a theory of the earth, that shall fully comprehend and explain all its phenomena. On this subject we may cherish a hope, congenial to the ardour and enthusiasm of science, that future generations, aided by ampler lights and a wider field of observation, may fully unravel that order and succession of appearances in the constitution of the globe, of which, at present, we have but a very dark and imperfect glimpse. The subject has already fixed, and will probably continue to attract the attention of men of the first ingenuity, as one of the most interesting and important objects of inquiry, in the whole circle of natural science. Though man was not stationed here, for the sole purpose of watching the revolutions of the globe; yet, as a thinking and intelligent Being, few things can interest him more than a knowledge of those changes, and of the fabric and laws of the planet which he inhabits.
In examining the surface of the globe, with a view to improve our knowledge of its structure and revolutions, no spot, however inconsiderable, that offers any thing curious or singular, is undeserving of notice. But whether the writer of this, in the account he has attempted to give of the structure of ST. HELENA, and in the conclusions, or rather conjectures, which he is about to draw from this, shall either satisfy the learned, or gratify the curious, must be left to the more unbiassed judgment of his readers. Whatever inferences, or conjectures, he has to propose, seem to himself at least to rise naturally out of the appearances which have been described. How far the analogy of these appearances may be extended to other parts of the earth, he is not sufficiently prepared to inquire: For though Nature, in raising this insulated mass from the bed of the sea, and in her manner of disposing its constituent strata, has unquestionably not departed from her established laws and order; yet the sphere of her agency here affords but a very limited and narrow view of the various effects of her subterranean operations; and it would be in vain to seek for the fabric and revolutions of the terraqueous globe, in the model of a little island in the Æthiopic.
That ST. HELENA has been the seat of volcanic fires will hardly be questioned by any one, who examines the materials of which it is composed: For to say nothing of the immense profusion of scorified, cavernous, light, spongy, and vitrified stones, which everywhere cover its surface, and the vast beds of the same sorts of stones, cemented together with lava, which penetrate its whole substance; even its hardest and most compact materials, bear evident vestiges of fire. The summits and bases of the basaltic rock are always more or less scorified, cellular, and honey-combed; and several of them of a smoky black colour, as if from the effects of recent ignition. In some of those beds of basaltes, which are interposed between the largest volcanic masses, we find the whole body of the rock excavated like the hollow trunks of decayed trees, and only a thin exterior plate of stone, remaining variously bent, and often beautifully curved and waved, which could not have taken place in a substance naturally brittle, without its being previously softened by intense heat. The interior surface of these hollow and excavated rocks are either coated over with small volcanic fragments, strongly cemented, or they are of bright and glossy colours, like polished metallic substances. From what agent but fire could all these effects proceed? But after the particular description which has been given of the different beds and layers, it seems unnecessary to waste time, in endeavouring to prove what will hardly be doubted, that a great part, at least, of the materials which compose ST. HELENA, must have flowed from the ignited crater of a volcano.
A question of more difficulty will naturally occur; whether ST. HELENA, as an island or fragment of some ancient continent, existed above water, before it became the seat of the volcano, which has so completely changed its structure and aspect? or, whether the whole is a volcanized mass, raised by successive eruptions from the bed of the sea to its present height?
At first sight, the remarkable difference observable between the interior parts and the hills on the shore, might lead us to suppose, that the former is a remnant of some primogenial land, which has been attacked and desolated by volcanos, the eruptions of which have formed all the surrounding parts of the island. This opinion is plausible; and though it will probably not satisfy those, who may in future examine things more closely, it is the one embraced by Mr. FORSTER. He observes, that he can venture to assert of several isles, from their external appearance, that they existed above water, before they had a volcano; and were entirely changed, and partly subverted by subterraneous fire. As he supports and illustrates this opinion from the present appearances of ASCENSION and ST. HELENA, which bear a great resemblance to each other, it may be proper here to quote what he says of both these islands.
"The dreariness of this island (ASCENSION) surpassed all the horrors of EASTER ISLAND and TERRA DEL FUEGO, even without the assistance of snow. It was a ruinous heap of rocks, changed by the fire of a volcano. Nearly in the centre of the island, rises a broad white mountain of great height, on which we discovered some verdure by the help of our glasses, from whence it has obtained the name of GREEN MOUNTAIN. On landing, we ascended among heaps of black cavernous stone, which perfectly resembles the most common lavas of VESUVIUS and ICELAND, and of which the broken pieces looked as if they had been accumulated by art. The lava currents, cooling very suddenly, may easily be imagined to produce such an effect. Having ascended about fifteen yards perpendicular, we found ourselves on a great level plain of six or eight miles in circuit; in the different corners of which, we observed a large hill of an exact conical shape, and of a reddish colour, standing perfectly insulated. Part of the plain between these hills was covered with great numbers of smaller hillocks, consisting of the same wild and ragged lava as that near the sea, and ringing like glass, when two pieces are knocked together. The ground between the heaps of lava was covered with black earth; but where these heaps did not appear, the whole was red earth. The conic hills consisted of a very different sort of lava, which was red, soft, and crumbling into earth. We concluded, that the plain on which we stood was once the crater or seat of a volcano, by the accumulation of whose cinders and pumice stones, the conic hills had been gradually formed; and that the currents of lava, which we now saw, divided into many heaps, had perhaps been gradually buried in fresh cinders and ashes; and the waters coming down from the interior mountains, in the rainy season, had smoothened every thing in their way, and filled up by degrees the cavity of the crater. The rocky black lava was the residence of numberless man of war birds and boobies, which sat on their eggs, and suffered us to come close to them. On all this rocky ground, we only met with ten shrivelled plants, which were of two sorts, a species of spurge and a bind weed.
"Having climbed over an extensive and tremendous current of lava, more solid than that near the shore, we came to the foot of the GREEN MOUNTAIN, which, even from the ship, we had plainly distinguished to be of a different nature from the rest of the country. The lava which surrounded it, was covered with a prodigious quantity of purslane and a kind of new fern. The great mountain is divided in its extremities, by various cliffs, into several bodies; but in the centre, they all unite and form one broad mass of great height. The whole appears to consist of a gritty tophaceous lime-stone, which has never been attacked by the volcano, but probably existed prior to its eruption.
"ST. HELENA, has on its outside, especially where the ships lye at anchor, an appearance, if possible, more dreadful and dreary than ASCENSION: but the further you advance, the less desolate the country appears, and the most interior parts are always covered with plants, trees, and verdure. However, there are every where the most evident marks of its having undergone a great and total change, from a volcano and earthquake, which perhaps sunk the greatest part of it in the sea.
"We visited (says the same author) isles that had still volcanos burning; others that had only elevation, and marks of being formed in remote ages by a volcano; and lastly, we found isles that had no remains of a volcano, but strong and undoubted vestiges of having been violently changed, and partly overturned by an earthquake, subterraneous fire, and a volcano. I cannot help referring EASTER ISLAND, ST. HELENA, and ASCENSION to the last." - These islands he supposes to have existed above the water before they were attacked by volcanos, or changed by the effect of subterraneous fire or earthquakes.
How far this opinion of Mr. FORSTER is probable with respect to ASCENSION and EASTER ISLAND, the writer, who has never had an opportunity of examining them, cannot venture to say. But with regard to ST. HELENA, this opinion seems to be founded on rather a cursory and superficial view of things; and it will be difficult to reconcile it with any part of the exterior fabric of the island, which lies open to investigation. If there is any portion of primogenial land here, it must consist of a central nucleus, which is hid from our view. All the superficial parts, from top to bottom, have the same analogy of structure, and the same volcanic appearances, dispersed through them. There is indeed, as has been observed, a remarkable difference between the composition of the interior heights and the hills on the shore. In the former, there is more clay and decayed stone: In the latter, more basaltic rock and volcanic cinders. But this difference, in the composition of these parts, is rather apparent than real, and seems to arise from the different proportions of the same materials, which are common to both situations. All the volcanic hills on the coast are traversed by thin layers of clay, and the interior hills, which are chiefly of clay, are penetrated by beds of basaltic rock and volcanic cinders and scoria. Even the huge perpendicular strata of broken and fissured rock, and the septa or cross ridges of decayed stone, which are so numerous throughout all the argillaceous hills, are, however, not peculiar to them, as several of the hills on the shore, consisting of parallel layers of basaltes, lava and clay, are also penetrated by vertical strata of shivered rock. That the interior mountains, consisting chiefly of clay and of rock, which is very much broken and fissured, should have undergone a greater decomposition than the surrounding parts, cannot appear surprizing; when it is considered, that these heights have long been covered with plants; and that from this circumstance, and their great elevation, they derive a more constant supply of moisture from the clouds; being frequently wet with rain, and inveloped in vapour, while the hills on the coast are scorched with sunshine. The decomposition which has taken place here, and the verdure which overspreads these lofty eminences, make them appear, at first sight, as altogether different in their nature, from the naked and rude hills that surround them. But this difference, as has been already observed, is rather apparent than real; and the effects of fire seem as plain and evident here, as in any other part of the island. The clays, or coloured friable earths, which compose the conical hills, seem to be of the same nature and fabric as the clays that are placed in layers between the volcanic beds on the shore; and the perpendicular strata, and oblique ridges of rock, are all cracked and fissured, and generally into regular portions, in a way similar to the horizontal beds of basaltes. From this analogy of structure and appearances, which prevails throughout every part of the island, is it not reasonable to conclude, that the whole has been raised from the bed of the sea by subterranean fire, to which it owes its peculiar form and conformation? This opinion seems to correspond with every appearance, observable in the present state of the island: Yet it is not easy to conceive, in what manner volcanic fires could, for a length of time, subsist at the bottom of the sea, without being extinguished; although philosophers have endeavoured to explain how this takes place, and some of them have supposed, that all volcanos are originally formed in this situation. Whatever difficulty, however, may attend our conception of it, and of the dreadful conflict between the burning lava and superincumbent ocean, the fact seems unquestionable, that the basis of ST. HELENA has been formed by successive eruptions under water, if indeed the Æthiopic existed at the time of its formation. There seems no way in which we can avoid this inference, or escape from the difficulties attending it, without supposing, that there is here some interior nucleus of primogenial land, which has served as a nidus to the volcano, and which may now lie concealed under its lava and cinders. But of this there is no evidence; the whole, to as great a depth as we can penetrate, being of the same volcanic nature as the parts above water. It is indeed near the water's edge, and under its surface, that we find the largest masses of lava and of volcanic cinders and scoria. These, in many places, where they are accessible to the tides, have been washed away, and have left deep excavations; from which cause, the bottoms of some of the hills are so hollow and cavernous, that they might easily present, to the fancy of a poet, the idea of an island floating on the bosom of the waves.
Some travellers, who have visited this island, and who have been struck with the wildness and irregularity of its aspect, without sufficiently attending to its fabric and conformation, have considered it as the effect of an earthquake, or some great subterranean shock, which bursting open the vault of the ocean, has suddenly protruded the whole upwards, and left it in the condition in which we now find it. But however gratifying it might be to think, that a portion of the interior globe could be thus exposed to human curiosity, appearances will not support us in thinking, that ST. HELENA has been raised in this manner: For, had it been suddenly raised by an earthquake, or any such convulsive shock, it seems probable, that the order and disposition of its parts must have suffered greater derangement and marks of violence from such a shock, than we actually find to be the case. The materials of which it is composed are so loose and disjointed, its hardest strata are often shivered into portions so minute, and so liable to separation, from the manner in which they rest upon one another, that any tremulous shock, like that of an earthquake, must, in elevating the island, have produced confusion in its component parts, and would probably have blended the whole into an undistinguishable mass. We might as easily believe, that an earthquake could raise a city, without throwing down its buildings, as to imagine that the hills of ST. HELENA could have been suddenly raised three thousand feet, without disturbing the position of the broken, loose, and hanging rocks, of which they consist. To suppose any elevating and expansive force acting so equably and uniformly on its base, as to raise the whole, without discomposing its constituent parts, is to suppose an existence of which we have no experience, and which, in its operation, would be altogether unlike those subterranean shocks, which bursting forth from time to time, have convulsed and deformed whatever was exposed to their violence.
It seems therefore probable, that this island must have been raised, not suddenly, but gradually, and that all the cracks and fissures in the horizontal, oblique, and perpendicular strata of rock, and in the layers of clay, must have been acquired in the position in which these strata now rest, and most probably in the act of cooling and hardening from a soft and liquefied state. For it seems impossible, in their present broken and disjointed condition, that they could have been elevated or exposed to any general and violent concussion, without suffering a total change in their order and disposition. There is indeed much irregularity, as has been observed already, in the direction and depth of the different strata. But the portions of which they consist are exactly fitted to each other; and, however minute the fragments into which some of the rocks are split, all the parts have yet preserved their natural position. Most of the irregularities discernible in the strata themselves, are only such as may have happened by ignited matter, flowing from volcanic craters, over irregular surfaces, with a greater or less declivity in different places, and in different proportions, during successive eruptions.
All the parallel beds of basaltic rock, volcanic cinders, and fissured clay, which compose the main body of the hills, seem to point out the progressive eruptions of those volcanos from which they arose; yet we can discover no remaining craters. These must have been obliterated by time, or they must have been filled up by some subterranean operation, which took place after the formation of the hills themselves; and there are some appearances, which will be mentioned afterwards, that render this last supposition probable.
It seems not likely, that the perpendicular and oblique strata of broken and fissured rock, which pass through the volcanic beds, could have existed before the formation of the hills, which support and keep them together in their present position; and it is impossible to conceive, that the parallel horizontal layers, and those that cross them, were the effect of operations, co-existent and simultaneous.- Whence it will follow, that the elevation of the perpendicular strata, and of the numerous oblique ridges of stone which intersect the hills, must have taken place at some period subsequent to the elevation of the island itself.
From all this, the most probable conclusion seems to be, that the various matters, composing the parallel layers of the hills, have been successively accumulated by volcanic eruptions: That these matters, on cooling and hardening, not only became fissured and cracked in the manner we find them, but that, in many places, the hills themselves were affected with larger rents and chasms, from the same causes: That all these rents and chasms, as well as the craters, were afterwards filled up with explosions of liquefied matter from below: That this liquefied matter, which, upon cooling and contracting, would also naturally become fissured and broken, as we see it, has formed all the perpendicular strata of rock, and the oblique ridges that cross the hills. This opinion seems conformable to every appearance which we meet with in the island; for all the beds and layers, which compose the main bulk of the hills, are unquestionably volcanic; and in many places disposed, as we should expect, by matter issuing from the mouth of a volcano; and on the spot where we should naturally look for a crater, we sometimes find an angular or conical mass of stone, or a huge vertical stratum, dividing the hill into two equal segments. As the clays and coloured earths would be more subject to rents and fissures than the stoney matter, we accordingly observe, that the argillaceous hills, more than any other part, are penetrated by vertical strata of rock, and intersected throughout all the declivities with numerous oblique ridges of cracked and shivered stone. From the loose texture of all these vertical strata and oblique ridges, and of the insulated and perpendicular masses of stone, it seems evident, as has been previously observed, that they must have acquired all their cracks and fissures, while in their present situation; as they could not possibly be displaced, without a total disruption of their component parts: That consequently, they must have been elevated, while in a soft and liquefied state from the effects of heat; and that afterwards, upon cooling and contracting, they became split and fissured in the manner in which we find them.
Here then we observe in the constitution of the island, the traces of two distinct operations, which could not have been simultaneous, but must have succeeded one another. By the first, the great mass of the hills has been formed by progressive eruptions from volcanic craters. By the second, all the rents and chasms of the island, as well as the craters themselves, have been filled up by subsequent explosions of ignited matter. It should seem then, that the subterranean sources which fed the volcanic eruptions, were not entirely exhausted, when the island was raised to its present height; but that, after a temporary cessation, they renewed their activity, and forced up torrents of burning and melted matter, thro' all the rents and clefts which had been formed in the hills. How intimately the whole island has been penetrated by some such explosions, which have passed thro' every previous chink and opening, we every where see abundant proof. Many of the beds of coloured earth and clay are perforated by plates of shivered stone, not above an inch thick; and many of the fissures in the basaltic rock are filled with veins of red earth, resembling brick-dust. All the argillaceous hills, as has been already noticed, are traversed by numerous oblique ridges of fissured stone; and besides the immense vertical beds that divide the hills, there are, in some places, huge perpendicular masses of loose and shattered rock, apparently unconnected with any extended strata. As these vertical and oblique strata could not possibly have preserved their position in a detached and insulated state, they must be of a date posterior to the hills that support them; and as they are here supposed to derive their formation from the effects of the same subterranean fires which raised the island, they ought not to differ essentially in their structure and appearance from the parts around them. We accordingly find, that all the stoney matter composing them, is of such a character, as to render it highly probable, that it must have been subjected to the action of intense heat, and elevated while in a soft and liquid state.
But, if instead of supposing that all these perpendicular and oblique strata of rock have been elevated, after the formation of the island, it should be thought a more obvious and natural conclusion, to consider them only as prominent and visible points of some interior nucleus of ancient land, which from having been formerly the seat of a volcano, is now overspread with its lava and cinders;- let it be remembered, that the strata in question bear such evident marks of fire, and of having been fused; that they are so intimately mixed and blended with substances confessedly volcanic; and that, in fine, all the superficial parts of the island are of a structure and appearance so analogous and corresponding, that it is very difficult to consider any particular part as separate and distinct in its origin from others. The whole, from the base to the summit, seems to be one great volcanized mass, consisting of irregular beds of volcanic scoria, basaltic rock, and coloured earths and clays; and these coloured earths, which appear only in minute lines among the hills on the shore, are the principal matter of which the interior heights and conical hills are composed. All these hills are traversed by the perpendicular and oblique strata in question; and no other supposition has occurred more probable to the writer, than that these strata must have been raised by some operation, subsequent to the formation of the hills which they pass through, and without the support of which, they could not possibly preserve their present situation.
During this last operation, the island may have been affected with some shocks and concussions, from the effects of that expansive force which was necessary to elevate the huge vertical beds and detached masses of rock; and such concussions may have produced much irregularity, without destroying the general structure and order of the whole. In this way, we may account for the confusion and irregularity which we meet with in some places, without the supposition of an earthquake. Yet, in a situation where there are so many unquestionable vestiges of subterranean fire, it would be absurd, and contrary to fact and experience, to suppose that no earthquakes have been felt. All that the writer contends for is, that the elevation of an orderly structure could not have proceeded from such a cause. That earthquakes frequently happen in the neighbourhood of volcanos is well known; and that they may have taken place at ST. HELENA, is therefore not improbable. But whatever shocks of this kind have been felt here, their effects seem to have been not to raise, but to sink some portion of the island into the sea; and several of the hills on the shore look as if a great part of them had been torn away, and separated by violence.
It also deserves notice, that the bed of the ocean, whether from the effect of earthquakes, subterranean fires, or the descent of currents of lava from the hills, is so ragged and irregular to a considerable distance, all round the island, that a person on sounding, finds it deepen suddenly, from fifteen to eighty or one hundred fathoms. It will hardly be doubted, that this inequality and abruptness in the bed of the sea, are in some way connected with the causes which raised the island itself, and the effects of whose operation may have extended to a far greater distance than it is possible to discover. We know, that ST. HELENA is not the only volcanic island in these latitudes; ASCENSION, which is nearly seven hundred miles to the northward of it, is of a similar structure, and of an appearance equally ragged and dismal. Of some others, which have been laid down in charts, very little is known; and the writer has been able to learn nothing. It seems not improbable, however, that they all may have had the same origin; and that volcanic fires, with very extensive subterranean communications, have anciently subsisted in the region of the southern Atlantic.
It is, indeed, impossible not be struck with the numerous remains of volcanos (some of them still burning) which are met with on the borders of this ocean, and of the northern Atlantic, between the latitude of ST. HELENA and ASCENSION and that of the AZORES. It was somewhere within this track, according to a tradition derived from the remotest antiquity, that a very large island was formerly situated, a little way to the westward of EUROPE and AFRICA, and said to have been equal to both in its extent. The origin of the numerous volcanos which encompass this space, may have had some connection with the earthquakes and subterraneous fires which are said to have destroyed that unfortunate land. Of its existence and submersion, we have only a very faint and imperfect record, transmitted to us by Plato, who derived his information from the traditionary Annals of the Priests of ÆGYPT. But the fact of the existence and destruction of such a land is the more probable in itself, as it only forms a link in that series of revolutions, which appear to have affected the whole surface of the globe. No one, who admits that EUROPE has been once the bed of the ocean (and few will question this) can doubt that a continent may anciently have occupied the bed of the Atlantic. If, according to Mr. FORSTER, ASCENSION and ST. HELENA really contain any portion of primogenial land, they might be regarded as two promontories or headlands, of some submerged continent, the volcanos of which, according to BUFFON, could only exist in the loftiest situations.
It may be inquired (but who shall satisfy such an inquiry?) whether ST. HELENA, which is so indisputably the effect of a volcano, is likely again to be affected by a renovation of those fires which produced it? It may be observed, that many volcanos, apparently extinct, have been suddenly rekindled; and that some, which had been dormant so long, that only a faint memory was preserved of their ever having been burning mountains, have yet burst forth with great violence. Such unexpected eruptions have proved the more calamitous, as the inhabitants of the country, trusting to the deceitful repose of those subterranean fires, and allured by the fertility produced from their ashes, had resorted to their neighbourhood, in unsuspecting security.
The first recorded eruption of VESUVIUS, in which PLINY the naturalist lost his life, and the cities of HERCULANEUM, STABII, and POMPEII were buried under its ashes on the same day, took place after a long series of ages had obliterated the remembrance of its ancient eruptions, though men of science suspected it to have been formerly a volcano. In the reign of TITUS, in which this eruption happened, it was all cultivated; and distinguished chiefly from other mountains by its amazing fertility. After this eruption, it continued to burn at intervals, during the period of a thousand years, when its fires again became apparently extinct, and remained so for almost four centuries, that is, from 1136 to 1506. During this long cessation, it is said, that every part of VESUVIUS was inhabited, and that a coppice, and pools of water, occupied the spot which is now its crater. After a repose of so many ages, it might naturally be considered as an extinguished volcano: Yet its fires only slumbered in their subterranean vaults, to burst forth with aggravated terror and calamity. During the last three centuries, there have been many dreadful eruptions of this volcano; and they seem to have increased in frequency and violence within the last hundred years.
It is now three hundred years since ST. HELENA was discovered. At that period, many of its loftiest summits, whence, it is probable, that the lava and cinders which every where appear in its composition had issued, were overspread with shrubs and plants. The formation of a soil, and the first growth of vegetables, in a situation so remote and unconnected, and apparently so unfavourable to the operation of those causes, which are known to transport the seeds of plants from one land to another, could only have been accomplished in a great length of time. And though we have no marks to guide us, in ascertaining what this period may have been, it seems reasonable to conclude, that at the time of its discovery, many ages had elapsed since ST. HELENA emitted fire or smoke, or shewed any signs of an active volcano. But, further, we do not find in this island, or its neighbourhood, any of those appearances which are usually met with in situations where there are active volcanos; or such as have broken out, after a long interval of rest. No shocks or earthquakes are felt here. There is no sign of any submarine volcano in the neighbourhood, and in the island itself there are no sulphureous, bituminous, or inflammable matters, or any circumstance from which we can infer the existence of any concealed subterranean fires. The surrounding atmosphere too discovers but seldom, and only in a very slight degree, any of those electric phænomena which are supposed to have a connection with the agency of volcanos. In fine, this island, and the circumambient ocean and atmosphere, having remained for many ages in a settled temperature, which seems to have suffered no interruption or disturbance, is it reasonable to infer from this and the other circumstances which have been mentioned, that the submarine fires, which anciently existed in this neighbourhood, have become permanently extinct; and that no latent source remains, which is likely to endanger their renovation? That all the inflammable mines, which fed the volcanos, have been exhausted, and that the submarine vaults themselves have been overflowed by the ocean, or otherwise obliterated? Such might naturally be the inference, if we could presume to decide this question by present appearances. But the question itself involves too many objects, which lye beyond the reach of our observation, to admit of a satisfactory solution. In every step which we take in such an inquiry, we are touching on the bounds of an undiscovered region, where the last glimmerings of probability die away, and are lost among the meteors of fancy.