Imágenes de páginas
PDF
EPUB

geography; if we philosophically search | into its origin and use in the universe, or wade through its history during the ages of its existence; if we survey its surface, and behold its productions, whether natural or agricultural, in its animal and vegetable life, or, sinking beneath its surface, pry into its internal structure, and note the approach of these foundations of the earth to day, in each of these wide-spread and wonderful connexions, we alike find rich divertisement and use; an interest and amusement in the exercise of the thinking faculty; and rise up from the study wiser and more strong for mental action, than when we sat down.

If, amidst our researches, we discover a new fact, this the thinking faculty dwells upon; its origin, its connexions, its uses, and all the etceteras in its train, rise up before the mind; and if in the researches which flow therefrom, some theory is mixed up of an uncertain character, yet the thinking faculty is exercised, and this exercise must be preferable to the torpidity of ignorance and inaction. We make the essay, and we learn something; and if we do not at once learn every thing, happy it is for us; for that which is yet to learn, will afford us the same interesting amusement as that portion of wisdom which we have already acquired, did in the learning. Employment, therefore, remains before us for the thinking faculty; and, from the multiplicity of objects around, will remain before us so long as we continue in time: yea, in all probability, much as our thinking faculty will be enlarged when this mortal shall have put on immortality, subjects will arise around us new to our intellectual energies to all eternity.

If we contemplate the earth geologically, we find a large proportion of its crust regularly stratified, even to the present hour, although some portions thereof are evidently in a state of ruin. I conceive the Creator formed the strata perfect throughout, and that the ruinous state of some of them may be attributed to the disruption of the great abyss immediately previous to the general deluge, which, for the crimes of the antediluvians, he brought upon the earth. Volumes upon volumes have been published, to prove that the strata of the earth formed themselves by depositions from water; or that they were formed by agents within or upon this sphere; and arguments, countless in number, and subtile as language can possibly convey, have been launched, in order to prove when and how these formations took place; but after wading through these oceans of literature, the mind finds nothing solid whereon to rest; and there

fore pants for a new system with as much eagerness, as if a single theory had never floated upon the stream of time.

The reason of this vacuum is apparent to every man, who has digested these theories; they are all deficient of the main requisitethey lack an intellectual cause for the observed effect-a cause which can, at once, plan and execute its purposes, viz. mind and power in union. No creature within the scope of our knowledge possesses these in any thing like the force required for such vast formations: the effects are far too great for a creature to cause; and the agents ordinarily called in, viz. fire and water, being devoid of mind, even linked with fortuitous circumstances, to which so much has been ascribed, are like the small dust of the balance, compared with the stupendous and wide-spread effects every where apparent in geology.

But when we turn to the volume of inspiration-that book through which Jehovah speaks to man, we behold " a great first cause," every way equal to the great effects which surround us, in the Creator of the heavens and the earth. The very first sentence of the Bible, therefore, throws more light upon this subject than all the volumes above referred to, inasmuch as it points us to a cause which possesses mind as well as power; it runs thus: "In the beginning GOD created the heavens and the earth"

Another paragraph, in the midst of the sacred volume, finishes what the first began, and places us at perfect ease as to the whole phenomenon of geology, viz. "The Lord is a great GoD, and a great King above all gods. In His hands are the deep places of the earth: the strength of the hills is His also. The sea is His, and He made it and His hands formed the dry land." Psalm 95.

Under the hands of Omnipotence, however difficult such stupendous formations may appear to man, the strata of the earth had their foundations stretched over the great abyss, and their inclined planes reared up to the highest mountain's height; their escarpments and sides sloped away, or formed into the abrupt; spreading into undulated downs, or projecting in precipices awful to behold, at the pleasure of the intelligent former. Therefore, on contemplating the imposing whole of this great sphere, or the detail of its parts, in connexion with this information, we behold what the universal grasp of the great Spirit has effected; and at once discern in the work, wisdom and power in union and action.

The strata of the earth, in their amplitude, are stretched out into two vast continents,

which, nearly parallel to each other, extend north and south, from the vicinity of the antarctic circle, to considerably within the arctic circle; and between these continents lie two immense oceans. In the midst of these continents several extensive mediterranean seas occur, and also many deeply indented gulfs and bays; but in no instance do any of these afford a communication from ocean to ocean. Amidst these oceans are numerous islands; some of these are of great extent, and others so minute that they may be denominated single rocks. The mediterranean seas, as well as the gulfs and bays, have also their islands; and some even of these are extensive. The islands are of a mixed character; for while some of these are as regularly stratified as the continents themselves, others are of volcanic origin; and not a few owe their existence to the coral insect, and to alluvial depositions. Shoals, or sunk islands, also occur in these oceans, both in the immediate vicinity of land, and at great distances therefrom; and lakes of water, in like manner, abound inland, or near the sea, both in the islands and continents.

The relative positions of these islands and continents have great effect upon the oceans, and also upon the general economy of the sphere; of which more hereafter.

Stratification is indispensable to the economy of a sphere, destined to supply the wants, and minister to the comforts and enjoyments, of animal life; but especially to that portion of animation to which reason is superadded, namely, man. If the crust of the sphere were not stratified, all the superfluous waters from rains, &c. would sink downwards, until every crevice was filled up, and the remainder would form pools upon the surface. These pools would afford the sun's rays water for immoderate evaporations, and the residue would become stagnant and putrid focuses of exhalations, deleterious to all animation. But the inclined planes of strata take in, at their utmost elevations, as well as at every aperture, these superfluous waters in such immense quantities, that no man, who has not experience therein, would imagine it possible they could contain them; yet these immense quantities are conveyed away by internal currents amongst the fissures of the rocks, or by filtration through less solid masses; every where giving out this water in springs, or affording it to wells at great distances from the places at which it entered; and the subsoils of whole districts are often laved thereby, to the fertilization of their fields, while the surface of the earth is by this means left dry.

That portion of the strata which projects

above the level of the ocean, forms the dry land; that which is more elevated, the hills and mountains; and that portion which is lower than the ocean, forms the bottom of the sea. It is probable the bottom of the sea is undulated similar to the dry land, having declivities in sundry places, as far below its surface as the acclivities which we call mountains, are in height above this level: and as the probability is, that the planes, escarpments, and sides of strata, beneath the ocean, are similar to those upon the dry land; were the ocean emptied of its waters, a fac simile, but in reverse, would be realized to our view, of the landscape around us.

Nothing could be more favourable to the formation of a world consisting of dense and rare, plain and mountain, sea and dry land, than series of strata so disposed as we find them in this sphere. The islands of the ocean perfectly harmonize with this; they are mountains in the sea, the tops of which rise above its surface, as the highest mountains rise above the clouds inland; and the lakes inland also harmonize therewith; their sides and bottoms are strata, the planes of which, being left bare from any incumbent strata, decline beneath the level of the adjacent country, leaving an extensive aperture, from which no outlet remains to drain the water.

The stratification of the islands corresponds to that of the continents, and they are evidently parts of the great whole. The island of Great Britain is a case in point; and the more we examine this island, and compare it with the continent adjacent thereto, the more we shall be convinced, that, although the ocean flows between it and the continent, it is a part of, and possesses the same character as the whole.

Stratification is the most compact bond and enduring covering a sphere of such magnitude as our earth can possess. Inclined planes of strata possess a treble bond. First, incumbency in a perpendicular direction; their own gravity disposing them towards the centre of the earth. Secondly, a connecting gravity, which disposes every atom therein to slide down its own inclined plane: this inclination prevents the several strata from separating with the same facility they would separate, if every stratum were an exact segment of the circumference of the sphere incumbent upon a similar segment: an under segment, if it settled, might part from an upper segment, which, being an arch, might sustain itself awhile, and then fall into ruin. And, Thirdly, an overlaying bond of each stratum, in respect of its fellow stratum, admitting the ends or escarpments as well as part of the planes, to the surface.

These escarpments also act as so many breaks in mountainous, and even in hilly regions, to the sweeping torrents generated there, stopping the soil at all points from being washed into the plains below, and thus preserving the surface of the earth in its original form.

When we examine the stratification of the sphere in reference to the declaration in the sacred volume, "The sea is His, and He made it, and His hands made the dry land," we behold the fabric as a masterpiece of the Great Master Builder; we view design and masterly execution; even the unwieldy bulk of the highest mountains, associated with the Infinite, dwindle into things of course, Beholding, as we do, the sun and the planets of this system, their attendant moons, and, wide spread through space, the stars of heaven, and counting, that He created, and He wields all these, the formation of a mountain is like the small dust of the balance; so far from holding it up as a vast achievement, we contemplate it as one of the minor works of God. But if we view a colossal mountain in reference to the theories of geologists in general; whether the Plutonian, the Neptunian, or the mixed system of fortuitous formations, be resorted to; or even if the whole are concentrated; we behold difficulties of the most formidable aspect, rear up and thicken around us; and whatever may be our efforts to subdue these, what we gain on the one hand, we lose on the other, until, overcome by hosts of perplexities, if we do not yield, we feel ourselves lost, even while we contend,

(To be continued.)

ON THE DEMONSTRATION OF THE DIURNAL MOTION OF THE EARTH.

It is well known that Galileo has experimented, and Dr. Keil demonstrated, that if any body be put in motion from a moving body, (as the earth,) it will communicate an equal motion or velocity to the body put in motion, in addition to the motion or velocity given to it; i. e. if a body from the surface of the earth be projected perpendicularly upward, it will fall on the spot whence it was thrown, although the earth was in rapid motion whilst it was in the air. But though this assertion is true, its vice versá is not; for if a body be let fall from the top of a tower, or from some elevated situation, it will not fall exactly at the foot of it, because the tower, &c, being perpendicular to the surface of the earth, may be considered as its radius continued: hence, as the earth revolves on its axis, the top

thereof will have a greater velocity than the bottom, or surface of the earth; consequently, a body let fall from thence will have a greater velocity communicated to it by the diurnal motion of the earth, than it would have had, if it had been projected upward from the surface of the earth; and as the earth revolves from west to east, it will fall a little to the east side of the foot, or of a plumb-line falling from the top of the tower; and this angle will be more perceptible where the tower is perpendicular to the axis of the earth, i. e. at the equator.

[blocks in formation]

Therefore, let the circle ADE FB be the plane of the equinoctial, which let revolve on the centre or axis C, from F towards D, and let FG be a tower, or some other elevated place.Now, suppose a

body to be let fall from G, the top, and suppose, while it is falling, that F will be moved to E, which will then be the foot of the tower; but, according to the foregoing principles, the body will fall on the point D, which will be as far distant from F as H is from G. Hence, suppose the tower or elevation FG 200 yards, the radius of the earth 3964 miles, and its circumference 24998,3 miles, then, by the laws of falling bodies, 16f.: 12′′ :: 600 f.: 37,3" and

37.36.1" time taken up in falling. Now, as 24 hrs.; 24998.3 mi.:: 6.1" : 1 mi. 1346 yds, space passed over by the foot of the tower, whilst the body was falling; and by similar sectors CEF, CHG, 3964 miles, 1 mi. : 1346 yds, :: 3964 mi. 200 yds.: 3106 yds. 3,2 in. DF, and 1 mi. 1346 yds. taken from 3106 yds. 3,2 in. gives 3,2 in. — DE; that is, supposing a body was let fall from an elevation free from oscillation 200 yards above the surface of the earth, it will fall 3,2 inches from a perpendicular, or plumb-line, if the earth is moving,

The question now is, whether it be possible to make the observation sufficiently correct to discover so small a quantity as 3,2; and the truth of this may readily be known in our own country. If we consider the accuracy of astronomical observations, we might be ready to conclude it possible: see how exactly the longitude may be dis covered, by taking the distance of the moon and stars, which distance must not deviate from truth scarcely any, otherwise the lon

[graphic][merged small]

The South-West End of the Volcano of Ki-rau-e-a, in Hawaii.

W. Cook jun. sc.

« AnteriorContinuar »