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immense currents have been caused by the tracts of land being left uncovered by the opening of fresh gulfs, into which the wa. retreat of the sea to its bed, the land beters have retreated at different periods ; came supplied with vegetables and animals. the last of which being that which reduced The deluge, he considers as a miraculous the waters to their present level.

effusion of water, both from the clonds and Patrin formed the opinion, that in the from the great abyss, which originated in, beginning, all the matters which now com- and proceeded from, the great southern pose the exterior part of the globe were ocean below the equator, and which rushing held in solution, or suspension in a fuid; into the northern hemisphere, descended and that, of these, some were deposited in southwards, and at length spread over the a crystallized state, as the granite, &c. face of the whole earth. whilst those which were not in a state of M. de la Metlerie, who has investigated actual solution, formed the different schists the subject with much attention, is of opiand other earthy, saline, and metallic nion, that all the mountains, vallies, and strata, regularly and concentrically disposed. plains, composing the crust of the earth, Whilst thus existing in a soft and yielding were formed nearly in the state in which state, the different substances, by acting on they now exist, by crystallization of the each other, he supposes to have passed into a mass of water which surrounded the earth. state of fermentation, necessarily productive The matters composing the highest mounof a swelling or raising up, which taking tains, he shows, have evidently been held place first of all in the granitic and saline in solution : the water, therefore, must have pasty masses, these were elevated, carrying reached above their summits, and of course with them, or bursting through, the other have stood 18,000 feet, at least, above its strata, thus forming the rocks and mountains, present level. But this being admitted, it now existing on the face of the earth. becomes necessary to determine what has

That respectable and excellent minera. become of the immense quantity of water logist, Mr. Kirwan, has zealously endea which has disappeared since that period. voured to form a system which may accord Of this he imagines, that some part has eswith the Mosaic account of the creation. caped by evaporation, and passed into He supposes the superficial parts of the other planets

, but trat by far the greatest globe to have been in a fuid state, being part is buried in the immense caverns which held in solution by water considerably exist in the interior part of the globe. heated. From the coalescing and crystal- On reviewing the systems which have lization of the contents of this solution, the been just enumerated, it is obvious that various metallic substances, the different some are so abundant im fanciful conjec. earths, &c. were deposited, in various com- ture, and so deficient of probability, as not binations, forming, according to the predo- to require any further remark; whilst in minant proportion of the ingredients, gra- others of a more specious appearance, there nite, gneiss, porphyry, and the other pri- are some points which cannot be allowed meval rocks. By the crystallization of to their ingenious authors. On these par these immense masses, a prodigious quan

ticular doubtful points, it is thought best. tity of heat was generated, even to incan- to offer a few remarks, rather than sepadescence, and the oxygen uniting with in. rately examine each system. With respect flammable air, occasioned a stupendous to crystallization from an aqueous solution, conflagration, by this the solid basis on a supposition wbich has not yet been genewhich the chaotic fluid rested, was rent to rally adopted, it may be remarked, that the a great extent. From the extrication, by primitive mountains and vallies give exactly this heat, of the oxygen and nitrogen gases, that irregularity of appearance, from lofty the atmosphere was formed ; and from the needle-like forms shooting up in some parts, union of the oxygen with igrited carbon, car and extensive plains existing in others, bonic acid proceeded, which being absorbed which are observable in cases of crystalliby calcarious earth, was precipitated in com- zation on the small scale. It has been ob. bination with it, forming the primitive lime- jected that the secondary mountains do not stones. The level of the ancient ocean be- every where cover the primary on which coming then lowered to the depth of 9000 they rest; this circumstance must, in all feet, fish were created; and the various probability, have depended on particular stratified secondary mountains were formed local circumstances, and especially on snch within it during its retreat, and after the as would, as in ordinary cases of crystallicreation of fish. Soon after, the higher zation, direct the formation of crystals more

causes.

numerously on one spot than on another. lofty mountains, rapid and violent car. Particular currents may perhaps be consi- rents of water, and various other powerful dered among the causes which assisted in producing these effects, as well as in form- By the preceding sketch of the numerous ing particular chains; wliilst to the action systems which have been advanced, and of contrary currents may be attributed the by these cursory remarks on some of the formation of separate mountains. The for- objections which have been made against mation of secondary mountains seems also those which appear to possess the greatest to concur with what is generally observed share of probability, the mind becomes betin tire ordinary progress of crystallization; ter prepared to attend to the system of the where it is observed, that after one series celebrated Werner, to whom, in the opiof crystals are formed of the least soluble nion of his learned and zealous annotator, matters, others are then formed of those

we owe almost every thing that is truly substances which the fuid was able to hold valuable in this important branch of knowstill longer in solution. It has been ob- ledge. For the purpose of conveying some jected against this system of crystallization notion of this ingenions system, the followof rocks, &c. that nature seems to perform ing sketch 'is taken from the view of it pothing of that kind at the present period; given in the “ Elements of Geognosy,” by but were this the fact, the objection would Professor Jameson. not possess much force, since a most satis

Agreeable to this system, the earth is factory answer might be yielded, by assert- supposed to have existed originally in a ing that the operation has ceased, in conse

state of aqneous fluidity, which is inferred quence of the task being accomplished; from its spheroidal form, and from the highand, speaking with respect to the granitic est mountains being composed of rocks, and porphyry rocks, all the materials being possessing a stmcture exactly resembling employed. The formation of stone by crys- that of those fossils which have, as it were, tallization is, however, carrying on in va. under the eye, been formed by water. rious situations at the present moment; From this circumstance it also follows that the incrustations formed in certain springs, the ocean must have formerly stood very and the various stalactitic formations which high over these mountains; and as these aptake place daily, are instances of this kind.

pear to have been formed during the same The unfitness of water to hold the sub- 'period of time, it follows, that the ocean stances forming the primitive rocks in solu- must have formerly covered the whole tion, has been considered as a powerful ob- earth at the same time. Contemplating jection; but it is to be considered, that the the formations of the mountains them. menstruum cannot be supposed to have selves, Werner discovered the strongest been simple water, but, as Mr. Kirwan proofs of the diminution of the original observes, this primitive Auid must have con- waters of the globe. He ascertained, 1st, tained all the various simple saline subthat the outgoings (the upper extremities stances and indeed every simple substance, as they appear at the surface of the earth) variously distributed, “ forming, upon the of the newer strata are generally lower whole, a more complex menstruum than than the outgoings of the older, from granite any that has since existed, and consequently downwards to the alluvial depositions, and endued with properties very different from this, not in particular spots, but around the any with which we have been since ac- whole globe. 2d. That the primitive part quainted.” Geological Essays, P. II. of the earth is entirely composed of chemi

Considerable difficulty must, however, cal precipitations, and that mechanical de. continue in adapting any system which positions only appear in those of a later confines the production of the various geo- period, that is, in the transition class, and logical phenomena which present them- thence they continue increasing, through selves to our observation to too few and all the succeeding classes of rocks. This to too limited causes ; since however neces- evidence of the vast diminution of the sary it may be to refer the general phe- volume of water which stood so high over nomena to the operation of one particularly the whole earth, is assumed to be perfectly powerful agent, it still must be neccessary satisfactory, although we can form no corto take into the reckoning the sinking and rect idea of what has become of it. the raising of particular spots from sub- By the earliest separations from the terraneous submarine fires; as well as the chaotic mass, which are discoverable in changes produced by the subversion of the crust of the globe, was formed a class of rocks, which are therefore termed primi- tains just appeared above the waters, when, tive rocks, being chiefly composed of silex, by the attrition excited by the motion of alumina, and magnesia, constituting by their the waves, and which we are reminded ex. various intermixtures, 1, granite; 2, gneiss; tends to no great depth, particles of the 3, mica-slate; 4, clay.slate; 5, primitive original mountains were worn off and lime-stone; 6, primitive-trap; 7, serpentine; deposited. 8, porphyry; 9, sienite; 10, topaz rock; As the height of the level of the ocean 11, quartz rock; 12, primitive finty slate; diminished, so would the surface on which 13, primitive gypsum ; 14, white stone. its waves acted increase, and of course the The circumstances which chiefly mark the quantity of the mechanical depositions. high antiquity of these rocks are, that Hence these are much more abundant in they form the fundamental rock of the the rocks of the next formation, which are other classes, and that the outgoings of denominated fleetz rocks, on account of their strata are generally higher than those their being generally disposed in horizontal of the other classes. Having been formed or flat strata. In these, petrifactions are, in the uninhabitable state of the globe, they very abundantly found, having been formed contain no petrifactions; and, excepting whilst vegetables and animals existed in the small portion which sometimes accom- great numbers. These rocks are generally pany those which will be next mentioned, of very wide extent, and commonly placed they contain no mechanical deposits, but at the feet of primitive mountains. They are throughout pure chemical productions. are seldom of very great height, from Small portions of carbonaceous matter oc- whence it may be inferred, that the water cur only in the newer members of the had considerably subsided at the time of class.

their formation, and did not then cover Before the summits of the mountains ap. the whole face of the earth. Countries peared above the level of the ocean, and composed of these rocks are not so rugged before the creation of vegetables and ani. in their appearance, nor so marked by mals, a rising of the waters is supposed to rapid inequalities, as those in which the have taken place, during which that class primitive and transition rocks prevail. The of rocks which are said to be of the second formations of this class are supposed to be, porphyry and sienite formation was de 1, first or old red sand-stone; 2, first or posited. The rocks of this formation are oldest flætz lime-stone; 3, first or oldest of clay-porphyry, pearl-stone porphyry, ob- fætz gypsum; 4, second or variegated sidian porphyry, sienite, and pitch stone, sand-stone; 5, second flætz gypsum; 6, They contain very little mechanical deposi- second fætz or shell lime-stone; 7, third tions, are of complete chemical formation, flætz sand-stone ; 8, Rock-salt formation; and contain little or no carbonaceous mat. 9, chalk formation ; 10, flætz-trap fornia. ter, and never any petrifactions,

tion; 11, independent coal formation ; 12, On the appearance of land, or during the newest flætz-trap formation. transition of the earth from its chaotic to Most of the rocks which have been just its habitable state, rocks which, from this enumerated are covered by a great forma. circumstance, are denominated transition tion, which is named the newest flætz trap. rocks, were formed. In these rocks the This formation also covers many of the_ first slight traces of petrifactions, and of high primitive mountains : it has but little mechanical depositions, are to be found. continuity, but is very widely distributed. The species of rocks which come under It contains considerable quantities of mecha. this class are the transition lime-stone, nical deposits, such as clay, sand, and gravel. transition-trap, grey-wackc, and flinty slate. The remains both of vegetables and ani. The petrificatious are corallites, encrinites, mals also occur very abundantly in these pentacrinites, entroclites, and trochites. The deposits. Heaps of trees and of parts of lime-stone of Derbyshire is said to be of plants, and an abundance of shells and this kind. As the former class of rocks other marine productions, with the horns of were purely of chemical formation, so the stags, and great beds of bituminous fossils, contents of these are chiefly chemical pro- point out the lateness of the period when ductions, mingled with a small proportion this formation was deposited. In this forof mechanical depositions. To explain mation several rocks occur which are also the cause of this mixture, we are referred met with in other flætz formations; but to the period of their formation, that at the following are supposed to be peculiar which the summits of the primitive moun- to this class, basalt, wacke, grey-stone, porphyry slate and trap tuff. These rocks respective owners, so that each might reare said to have been formed during the possess his property. It seems probable, settling of the water consequent to a vast that, in the operations attendant on that deluge, which is supposed to have taken act of justice, many discoveries were made place when the surface of the earth was relating to the properties of figures, which covered with animals and vegetables, and gradually led on to an extension of the when much dry land existed. From vari- science, and to the cultivation of the arts of ous appearances observed in these rocks navigation and astronomy, which, indeed, it is concluded, that the waters, in which first flourished in that quarter. We are rathey were formed, had risen with great ther in the dark as to many improvements rapidity, and had afterwards settled into a made in the infancy of geometry, and its at. state of considerable calmness.

tendant speculations; many tracts of supThe collections and deposits derived posed value having been entirely lost, from the materials of pre-existing masses, though some faint traces and fragments of worn down by the powerful agency of air their subjects, if not of their contents, have and water, and afterwards deposited on the from time to time been discovered. The land or on the sea coasts, are termed allu- Grecians appear to have been enthusiasts in vial, and are, of course, of much later for their reception of the new science; accordmation than any of the preceding classes. ingly, we find that Thales, Pythagoras, Ar. These deposits may be divided into, 1. chimedes, Euclid, &c. exerted themselves Those which are formed in mountainous to instruct their countrymen, and thus to countries, and are found in vallies, being prepare the way for the philosophy of composed of rolled masses, gravel, sand, Ptolemy, Copernicus, and others of the and sometimes loam, fragments of ores, ancient school; and of Des Cartes, Leibnitz and different kinds of precious stones. 2.

and the immortal Newton, in onr more en. Those which occur in low and fiat coun- lightened times. At present, geometry is tries, being peat, sand, loam, bog iron justly considered to be the basis of many ore, nagelflech, calc-tuff and calc-sinter: the liberal sciences, and to be an indispensable three latter being better known by the part of the education of those who purpose names breccia, tufa, and stalactite.

exercising even the more mechanical arts In this ingenious system, in which so to advantage. much knowledge of the subject prevails,

We shall submit to our readers a general and in which the marks of long and patient view of this most useful and fascinating at. investigation are evident, a very close ac- tainment, and, by a gradual display of its cordance with geological facts is generally rudiments, open the field to further adobservable. Some few difficulties however vancement, which may be easily insured by occur, particularly it seems with respect to consulting those authors who have become the new trap formation; since although eminent for the display of whatever relates the appearances which this is intended to to the superior branches of geometry. In explain do not better agree with any other the first instance, we shall submit the fol. supposition, still the rising of the waters lowing definitions, as laid down by Euclid whilst they yet covered the summits of the in his Elements, recommending them to the primitive mountains, has much the ap-' serious attention of the student; they being pearance of a supposition made up for this absolutely necessary towards his competent particular purpose; and as, at the same time, appreciation and understanding of the sucit appears to be warranted by no other ceeding propositions. phenomena, it seems to require some further

DEFINITIONS. consideration, before it is fully admitted. 1. A point hath neither parts nor magni.

For more particular observations on the tude. 2. A line has length, without breadth. yarions characters, and on the different 3. The ends, or bounds, of a line are points. classes of rocks, see Rocks.

4. A right line lies evenly between two GEOMETRA, in natural history, one of points. b A superficies, or plane, has only the families of the Phalæna genus of in- length and breadth. 6. Planes are bounded sects. See PHALÆNA.

by lines. 7. A plain superficies lies evenGEOMETRY, in its original sense, re. ly and level between its lines. 8. A plain lated simply to the measurement of the angle is formed by the meeting of two right earth, and was invented by the Egyptians, lines. 9. When an angle measures 90 dewhose lands being annually inundated, re- grees, it is called a right angle. 10. When quired to be frequently measured out to the less than 90 degrees, it is said to be an acute angle. 11. When more than 90 degrees, it cagon ; with twelve, a dodecagon. 36. A is called an obtuse angle. 12. A term, or solid has length, breadth, and thickness. bound, implies the extreme of any thing. 37. A pyramid is a solid standing on a base, 13. A figure is contained under one or more of any number of sides, all of which conbonnds. 14. A circle is a plain figure, verge from the base to the same point or contained in one line, called the circum- summit. 38. When standing on a trianguference, every where equally distant from a lar base, it is called a triangular pyramid; certain point within it. 15. That equi-dis- on four, a square pyramid; on five, a pentant point within the circle is called its tagonal; and thus in conformity with the centre. 16. A line passing from one side figure of its base. 39. Every side of a py. to the other of a circle, and through its cen- ramid is a triangle. 40. A cone is found tre, is the greatest line it can contain, and by the revolution of a triangle on its apex, is called its diameter. 17. The diameter or summit, and a point situated in the cendivides the circle into two equal and similar tre of its base; therefore a cone (like a suparts, called semicircles. 18. When a line gar-loaf) has a base, but no sides, 41. A shorter than the diameter is drawn from one prism is a figure contained under planes, point to another on the circumference of a whereof the two opposite are equal, similar, circle, it is called a chord. 19. The part of and 'parallel ; and all the sides parallelothe circle so cut off or divided by such line grams. 42. A sphere is a solid figure, geor chord is called an arc or segment. 20. nerated by the revolution of a circle on its Figures contained under right lines are cal- diameter, which is then called the axis, led right-lined figures. 21: A figure having 43. A cube is a solid formed of six equal three sides is called a triangle. 22. If all and mutually parallel sides, all of which are the sides of a triangle are of the same length, squares. 44. A tetrahedron is a solid conit is called an equilateral triangle. 23. If tained under four equal, equilateral triangles. all the sides and angles are unequal, it is 45. A dodecahedron is a solid contained called a scalene triangle. 24. If two of the under twelve equal, equilateral, and equiansides are of equal length, it is called an isos- gular pentagons. 46. An icosaliedron is a celes, or equi-crural triangle. 25. If con- solid contained under twenty equal, equilataining a right angle, it is called a right- teral triangles. 47. A parallelopipedon is angled triangle. 26. The long-side sub- a figure considered under six quadrilateral tending, and opposite to, the right angle is figures or planes, whereof those opposite are called the hypothenuse. 27. When the two respectively parallel. 48. Figures, or boshortest sides of a triangle stand at a greater dies, are said to be equal when their bulks angle than 90 degrees, the figure is said to: are the same; and similar, when they are be“ obtuse;" and when all the angles are alike in form, though not equal. 49. Thereacute, it is called an acute-angled triangle. fore similar figures or bodies are to each 28. When two lines preserve an equal dis- other in proportion to their respective areas tance from each other in every part, they or bulks. 50. The line or space on which are said to be parallel. 29. Parallel lines a figure stands is called its base ; its altitude may be either straight or curved, but can is determined by a line drawn parallel to never meet. 30. A figure having four its base, and touching its vertex, or highest equal sides, and all the angles equal, is part. 51. A right-lined figure is said to be a square. 31. But if its opposite angles inscribed within another, when all its proonly be equal respectively, the figure will jecting angles are touched thereby. 52. The then be a rhombus, or lozenge. 32. When figure surrounding or enveloping another is all the sides of a figure are right lines, and said to be described around, or on it. 53. that the opposite sides are parallel and When a line touches a circle, and proceeds equal, it is called a parallelogram. 33. If without cutting it, such line is called a tanthe opposite sides are equal, the others be. gent. 54. Any portion, less than a semiing unequal, the figure is called a rhom- circle, taken out from a circle by two lines, boides. 34. Four-sided figures, unequal in all or radii, proceeding from the centre, is calrespects, are called trapezia. 35. Figures led a sector. having more than four sides are called poly- Certain AXIOMs are likewise proper to gons, and are thus distinguished: with five be carried in mind; viz. 1. That things equal sides, it is called a pentagon ; with six, an to one and the same thing are equal to one hexagon; with seven, an heptagon; with another. 2. If to equal things (or numbers) eight, an octagon ; with nine, an enneagon; we add equal things, (or numbers) the whole with ten, a decagon; with eleven, an ende. will be equal. 3. If from equal things we

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