LESSONS IN GEOGRAPHY.—No. IV. In our last lesson, we referred to the influence of the writings of Ptolemy on the geographical knowledge of later times. According to him, the limits of the world were Thule on the north, and the Prassum Promontorium on the south; the former being most probably some part of Norway, and the latter some unknown point south-west of Madagascar. Its limits on the west, were the Fortunate Isles, now the Canaries; and on the east, Thinæ in Sinæ or China. He rejected the theory of all preceding geographers, who represented the world as surrounded by an impassable ocean on all sides; and he replaced it by an indefinite expanse of terra incognita (unknown land). He rejected the true reports of circumnavigation of Africa, and extended its limits southward beyond all reasonable bounds. With Europe, Ptolemy was tolerably well acquainted; and he described Germany and Sarmatia with some degree of accuracy. He knew the Ems, the Weser, the Elbe, the Order, and the Vistula. He calls Jutland the Cimbric Chersonese, and the Baltic, the Sarmatic Ocean, but he failed in his account of this inland sea. He was better acquainted with the south of European Russia, with the Tanais, the Borysthenes, and the Euxine. In his description of the Mediterranean, there are many errors, but his account is more accurate with them all, than that of any previous geographer. In regard to Asia, his knowledge was obscure and unsatisfactory, though some features can be still identified with fact. Here he described the "Golden Chersonese," and the Magnus Sinus, or Great Bay of India; these appear to have the Indo-Chinese countries of Ava, Pegu, and Malacca, with their adjacent gulfs or bays; and Thine, which he places at this remote corner, is supposed to be Siam, rather than any place in China. and mystery; its northern part only is seen, the rest is unap- The Serica of Ptolemy in the north of Asia is supposed, with good reason, to be China, which was reached by great trading caravans which proceeded from Byzantium (or ConThe expeditions we have now referred to were turned to stantinople), across Asia Minor, crossing the Euphrates at some advantage by the geographers of the period, but all the Hierapolis, and passing through Media, by way of Ecbatana to light they were calculated to give was not rendered available. Hecatompylos, the capital of Parthia. Their next route was The learned writers of the tenth, eleventh, and twelfth cenHyrcania, Aria, Margiana, and Bactria; whence, they ascended turies still united the Frozen Ocean, the Baltic, the White Sea, the table-land of the interior of Asia, passed over the Montes and the Caspian. They believed that all the northern regions Comedorum, or Beloor Mountains, and reached the celebrated formed only one island. Then the Amazons, those famous Lithinos Pyrgos or "Stone Tower," a station whose site is still warriors, whose country antiquity had placed to the north of a doubtful question among geographers. From this station to the Caucasus, were now removed to the countries newly disthe frontier of Serica was a seven months' hard and perilous covered in the north of Europe. Scandinavia became their journey. The description which Ptolemy gives of Serica birthplace and their residence. "The fiction of the Amazons,' corresponds more exactly to China than any other country; says M. Humboldt, "has travelled over all the zones; it beand his account of the manners and customs of the inhabit-longs to a complete circle, which proceeds from the reveries ants, identifies it still more. Moreover, the staple commodity and ideas in which the poetic or religious imagination of all of this overland trade was silk, for which China has been cele- races of men, and of all periods, instinctively performs its brated from time immemorial. Ptolemy appears to have had evolutions." a considerable knowledge of Hindostan or India, both within and without the Ganges; a knowledge said to be superior to that of the moderns till within the limits of the present century. With regard to Africa, this statement may just be reversed. But taking his work as a whole, and considering the age in which it appeared, it must be considered a singular monument of industry, and a valuable book of reference in all matters relating to the ancient geography of the world. PROBLEMS AND QUERIES. 1. Given the heights of three towers placed at the angular points of an equilateral triangle, a, b, c, in the order of their magnitude; with the base or side of that triangle, d; to find the point within the triangle, where a ladder must be placed to reach the top of each tower; that is, the distances of this point from the angular points of the triangle; and also the length of the ladder. Keith's Arithmetic, the heights given, 28, 30, and 34 feet; and the side of the equilateral triangle, 50 feet. In 2. Required a number such that when added to, or subtracted from its square, the sum or remainder shall be a square number. 3. Three gentlemen contribute £164 5 towards the building of a church at the distance of 2 miles from the residence of the first, 23 miles from that of the second, and 3 from that of the third. They agree that their shares shall be reciprocally proportional to their respective distances from the church. How much should they individually contribute? From the time of Ptolemy down to the tenth century of the Christian era, no geographical work appeared, either to supply the place of his, or to add to the knowledge which it conveyed. The invasion of the Roman empire by the northern hordes, the general anarchy which followed, and the seclusion into which literature was driven, produced a retrogression of all the arts and sciences, and especially of geography. A proper judgment may be formed of the ignorance which prevailed in this science immediately anterior to the time of the Crusades, by inspecting a map of the world published at that period. The sea, as in the age of Homer, is made to surround the world, which is divided into three parts, Europe, Asia, and Africa. Asia is as large as the other two parts; Africa is joined to Asia on the south, and the Indian ocean is made an inland sea. On the east, there is a small place indicating the position of the garden of Eden, by the words Hic est paradisus. Europe and Asia are separated from Africa by a very long canal, which 6. Through a given point to draw a line such that the segment some believed to be the Nile, others the Hellespont, and others of it, intercepted between two given parallels, may be equal to a again the Indian sea. Africa is considered the country of fable given straight line, 4. To find a square which shall be equal to the difference of two given squares. 5. Through a given point within or without a given circle, to draw a chord that shall be equal to a given straight line. ANSWERS TO CORRESPONDENTS. JAMES POLLITT is informed that the "Manual of the French Language," price 28., is the title of the work respecting which he inquires. A copy of the "Lessons in French," as we have had occasion to say in reply to various correspondents, will be sent through the post direct from our office to any address, on the receipt of seven penny postage stamps. W. W. (Coventry): We really are not aware of any books we can recommend on the subjects he meations; but they will be treated of in due time in the POPULAR EDUCATOR. A meniscus lens is convex on the one side and concave on the other. The latest information on Photography and Daguerreotype, will be found in the official Illustrated Catalogue of the Great Exhibition, at Nos. 291, 292, 296, 297, 299, 303, 404, Class X.-TYRO (Newcastle), will be gratified with lessons in the other ancient languages as soon as convenient.-O. (Monebar): Greek, &c., all in good time.-GRACE E―G, will find an answer to her principal question at page 176, col. 2, line 14; and to her secondary questions at page 22, col. 2, lines 12 and 17 from the bottom. We request our friend, R. P. (Islington-green), not to despair; we are preparing a cheap edition of Euclid for those who are anxious and willing to learn. He has given us no trouble. Let him try, try again. -J. S. (Port Glasgow) is right; 26 numbers will form a volume.-Our excellent friend, E. H. M. CAM, is informed that there is a fine paper edition at 14d. each number, which wants the title of which she complains. -Z. R. (Birmingham): Will find mentioned among our Literary Notices, a "Handbook on Emigration," price 9d.-H. CARTNEY (Dublin), is informed that in No. 6, p. 96, col. 1, line 6 from the bottom, there is a reference which we hope will satisfy him on the subject of chronology. -We recommend our friend PILATE to observe the same reference on chronology. When Greek comes up rules will be given for its pronunciation.-X. Y. Z.; F. B. (Horsham); R. C.: Painting, architecture, and colour will come in due course.-T. C. LATHBRIDGE (Fitzroy-square): Chemistry will appear in its turn. J. B. R. (Glasgow): We do intend to give distinct treatises on Natural Philosophy, Mechanics, Engineering, Drawing, &c.; but we do not see the necessity of "groans;" if there be any one thing that requires expla nation, we hold it our duty to give it, independent of either groans or cheers.-I. P. (Manchester), an "Enquirer" is informed that when we have ascertained what other system of "Shorthand" is best, we shall give it. Mr. Pitman's is copyright. JOHN BOURTON (Paddington): His solution of the cases of the 47th are ingenious.-R. M, ROBSON (Sunderland): We thank him for his suggestion; it will be considered.-E. FINIGAN (Manchester): His solution of query 2, page 111, is correct.-WILLIAM PARKER (Newnham): His suggestions are good and practical. Our address is "Editor of the the Popular Educator," 9, La Belle Sauvage-yard, Ludgate-hill, London. It is not necessary that every student should study all that is in every number at one and the same time. Does our correspondent not see that the variety is absolutely necessary to ensure a greater number of readers? In this way, every one may take up what he likes best; and let the rest stand over till another opportunity. The subjects will keep. We shall thank him for the list of words, which he cannot make out in the French vocabulary.-JOHN MACKAY (Whitehaven): When Latitudes are mentioned in the newspapers, if they are not marked N. or S. they are useless. When Longitudes are mentioned without being marked E. or W. they are equally useless. Latitudes, when properly marked, are estimated North or South of the equator. Longitudes, when properly marked, are estimated East or West of the first meridian, which among us, is the meridian of the Royal Observatory at Greenwich, and not of London. The Latitude of the Royal Observatory is 51° 28' 39" N., and its Longitude 0° 0' 0." The Latitude of St. Paul's Church, London, is 51° 30′ 49′′ N., and its Longitude 0° 5′ 47′′ W. gives out rapour, and that vapour has a certain pressure; but at 212° BOTANY.-A SCHOOL ASSISTANT: The statement about which our correspondent inquires is quite correct. A thyrsus is a panicle whose middle branches are longer than those of the base and 2pex. The peduncle is the stem or stalk that supports the fructification of a plant, and different lengths of the peduncles give to the lilac its ovate form.— SCIRE FACIAS: The effect about which our correspondent inquires is probably to be ascribed to the attack of a gall-fly; but the blossom was too much decayed to allow of a more precise answer. FRENCH.-JEUNE FRANÇAIS is right; but we fear that Lessons on Pronunciation would take up too much of our room, and could not be made quite to accomplish the desired end; for, after all, the living voice is very necessary for those who wish to speak French. WHITTET (Edinburgh) is right in his correction; it will be noted.-UN JEUNE ECOLIER (Preston) gives us great pleasure when he informs us he is getting before us in our lessons: we hope to be up to him soon.-J. C. HILL: Right.-O. D. H. WELLS (Somerset): His offer is both admirable and generous; we shall take it into serious consideration.-C. DAVIS (Whitechapel): Something will soon be done to meet his wishes as to French and Latin. ENGLISH GRAMMAR AND COMPOSITION.-R. MASON (Lancashire), is informed that Dr. Beard's Lessons will include English Composition, see No. 10, page 150.-C. E.W. The sounds of ee and e are the same in the words thee and me; but the sound of e in the definite article the is very different, and approaches one of the sounds of a.-A. E. should learn English grammar first.-G. HOGG (Newcastle), is right: the positive is not strictly a degree of comparison, but it is the starting point; if we had it not, we could not compare. A man must be good in some degree before we can say that another is better. ERRATUM IN SOME COPIES. page 139, line 42, col. 2, for tenth read eleventh. LITERARY NOTICES. HISTORY OF THE PAINTERS OF ALL NATIONS.--The first part of this magnificent work, in imperial quarto, containing a portrait of Murillo, and eight specimens of his choicest works, including the "Conception of the Virgin," lately in the collection of Marshal Soult, and recently purchased by the French Government for the Gallery of the Louvre, for the sum of £23,440, is now ready. The successive parts will appear on the first of every month, at 28. each, and will be supplied through every bookseller in town or country. CASSELL'S SHILLING EDITION OF EUCLID.-THE ELEMENTS OF GEOMETRY, containing the First Six, and the Eleventh and Twelfth Books of Euclid, from the text of Robert Simson, M.D., Emeritus Professor of Mathematics in the University of Glasgow; with Corrections, Annotations, and Exercises, by Robert Wallace, A.M., of the same university, and Collegiate Tutor of the University of London, will be ready early in July, price 18. in stiff covers, or 1s. 6d. neat cloth. SCRIPTURE LIBRARY FOR THE YOUNG, in Shilling Volumes-The first two volumes of this instructive series of works, "The LIFE of JOSEPH," illustrated with sixteen choice engravings and maps, and "The TABERNACLE, its PRIESTS, and SERVICES," with twelve engravings, are now ready. The "LIFE OF MOSES" is in the press. THE ILLUSTRATED EXHIBITOR AND MAGAZINE OF ART.-The First Volume of this splendidly embellished work, handsomely bound price 68. 6d., or extra cloth gilt edges, 78. 6d., is now ready, and contains upwards of Two Hundred principal Engravings and an equal number of minor Engravings, Diagrams, &c. HISTORY OF HUNGARY, WITH upwards of EIGHTY ILLUSTRATIONS. -The First Volume of the New Series of the WORKING MAN'S FRIEND, neatly bound in cloth, price 38. 6d., contains the completest History of Hungary ever published; also, a History of China and the Chinese, with Forty-six Illustrations of the Manners, Customs, Public Buildings, Domestic Scenes, &c., of this most remarkable people; towith Portraits; Scientific and Miscellaneous Articles, &c. A SCHOOLMASTER, who wishes to obtain a certificate of merit for his acquaintance with geometry, should read the lessons in the POPULAR EDUCATOR, and the edition of Euclid just announced.-JOHN WRIGHT (Glasgow), is right; we were obtuse not to see the error; it will be rectified.-T. B. ULMER, Philos, proposes an excellent mode of drawing a perpendicular; make a triangle whose base is 3 equal parts from any scale, and two sides 4 and 5 equal parts, respectively, from the same scale; then the angle opposite the side containing 5 equal parts will be a right angle by the 48th Prop. of Book I., Euclid's Elements. Any equi-multiples of these numbers will do as well, and many other num-gether with numerous instructive Tales and Narratives; Biographies, bers, as, 12, 5 and 13, &c.-H. DUGDALE (Slaidburn), has sent us a very ingenious solution of query 5, page 111, being an ocular demonstration of the problem; we shall take an early opportunity of noticing it in our pages.-W. S. BATT (Sheerness): His solutions of problems 1, 2, 3, page 111, are correct. His different values of s should be all the same, and will be so, if worked fully out. We thank him for his accompanying letter. A CLACKMANNANSHIRE "HERD" has sent us correct solutions of problems 2 and 3, same page.E. C. HUGHES (Islington): Thanks for his solutions. As to his query on steam, water generates steam at 212°; below that it only generates vapour; and above that it generates high-pressure steam, which becomes dangerous in proportion as the degree rises above 212°. Ice CASSELL'S EMIGRANT'S HANDBOOK, a Guide to the Various Fields of Emigration in all Parts of the Globe, Second Edition, with considerable Additions, and a Map of Australia, with the Gold Regions clearly marked, is now ready, price 9d. THE PATHWAY, a Monthly Religious Magazine, is published on the 1st of every month, price twopence-32 pages enclosed in a neat wrapper. Vols. I. and II., neatly bound in cloth and lettered, price 2s. 3d. each, are now ready. Printed and Published by JOHN CASSELL, 335, Strand, and Ludgate-hili, ON PLUTONIC CHANGES IN THE STRATIFIED SURFACE OF THE EARTH. You have become acquainted with three causes which have contributed to the production of the earth's crust. These are1, the first hardening of the surface by cooling; 2, the action of subterranean heat in throwing up eruptive rocks through fissures to the surface, and also consolidating "nether-formed" rocks below the crust; and 3, the action of water in dissolving, wearing away, or disintegrating, portions of upper rocks, and carrying down the sand, or detritus, to deposit it at a lower level. are on a higher level than the crust A, from which the materials were originally worn down; or of which A has been denuded. Since the laws of Hydrostatics would prevent water from depositing matter at this high level, the elevation of the beds must be ascribed to the action of the heat from below. Upon an examination of sedimentary rocks, there are two inferences which you cannot avoid making. The first is, that the rock which has been worn or abraded by the water, must have been older than the rock formed by disposition. The second is, that the rocks thus worn by running water must, at the time of disintegration, have been at a higher level than the place where they are deposited. To this second inference, there is one exception. Water, hot or boiling, has a greater disintegrating power to act upon rocks, chemically, than when it is cold. When the earth's crust, therefore, had only just become cool enough to allow water to exist upon it, in a fluid state, and not in one of vapour, the heated, boiling, agitated waters must have worn away the granite at their bottom very deeply and extensively. These abraded materials which the waters held in solution or suspension, they would deposit, either in deeper hollows, or along surfaces, that were of a lower temperature. There are some phenomena developed in the condition of some of these sedimentary rocks that will greatly puzzle a young inquirer when he meets them for the first time. They are sometimes on a higher level than the rock from which their sands or clays have been derived. In other cases, they are so altered in general aspect and mineral character, that he would hardly recognise them as stratified deposits. In other places, they are so disjointed, dislocated, and separated from the series, of which they formerly constituted a continuous part, that their stratification appears almost reversed. All these changes are owing to the action and force of subterranean heat, as will be shown in the following illustrations, Fig. 6. This elevation would take place gradually and tranquilly, in consequence of the slow expansion of the crust A B. This elevating expansion of the crust is not represented in fig. 5, which is only designed to show the action of heat in altering rocks. Before the sedimentary rocks had been deposited, the crust A B parted with its heat freely: but deposits of clay conduct heat very slowly, and the consequence would be that the temperature of the stratum, below such beds of clay, would increase to a higher degree. The increase of heat in the stratum below, would enlarge its bulk by expansion; which, in its turn, would elevate the newly-formed deposits, above their former level; so that what was once the bottom of the sea may become a large island or small continent. This you will more easily understand, if you imagine that, previous to the elevation of FDG, a sea existed on the line FG. It is not the science of geology only which asserts and proves that such elevations have taken place in very remote ages; for our own observation can demonstrate that they take place in our day. The changes of level which take place along seacoasts, are ascribed, by the common people, to the sea receding; but geologists can show that the change is the result of the earth rising. Even so late as the year 1822, in the neighbourhood of ValSouth America, was raised three or four feet above its usua paraiso, the whole coast of Chili, on the western side of level along a line of more than a hundred miles in length. There could be no doubt of this elevation, for, after a tremendous earthquake, an old ship that lay as a wreck at some distance in the water, could, after Nov. 20th of that year, be safely visited dryshod: and an extensive bed of oysters and mussels, of whose existence the inhabitants of the city knew nothing, was now exposed, which with the dead fish contaminated the air with their bad odour. At this moment, the coast of Sweden, from rising at the rate of about three feet in every hundred years; Frederickshall to Abo in Finland, is gradually, but visibly, but the rate varies in different parts of the coast. This elevation is proved by the fact, not only that shores are now dry which used to be covered at low water, but, that the shells of The elevation and alteration of sedimentary portions of the earth's crust by subterranean heat. In fig. 6, is represented a large portion of the earth's crust, covered by sedimentary rocks, which have been deposited by the action of water. A B represents the original crust now resting on the nether-formed rock c, to which reference was made in Lesson III. DE are sedimentary beds, deposited on the crust in its primitive state along the line F B. The deposits VOL. I. G E B C sea. fish which now live in the Baltic abound in the soil which is about four feet higher than the water, and that at the distance of about seventy miles from the present margin of the It is also a fact that barnacles, shellfish which attach themselves only to rocks or walls washed by the sea, are now found fixed on high parts of the cliffs; which proves that these cliffs with their barnacles were once at a level which could be washed by the sea. You therefore see, that wherever the sea is receding, it is occasioned by the earth rising, and that this rising is caused by the expansive power of heat below. While heat is, by expansion, affecting and elevating rocks that are remote from it, it is acting with greater intensity upon the rocks which lie nearest to it. It is consequently found, that, when the lower beds of the sedimentary rocks lie near enough to the fusing power of heat, they are the most altered by it, both in appearance and even in mineral, or lithological character. This is represented above in the darkened portion of the beds FDE, fig. 5. This operation of subterranean heat in altering sedimentary 16 rocks is not, in this lesson, to be mistaken for the action of volcanic intrusions, whether of granite, of basalt, or of trap, to which future lessons will refer. Both actions are analogous to each other: but this lesson refers to very early changes which have taken place in the earth's crust, and which might have been expected from the influence of intense melted matter, and from the effort of disengaged gases struggling to make their way through the porous rocks that overlay them. The alteration which intense heat produces in a sedimentary rock, will always be according to the nature of the deposit of which it is formed. Shale, a laminated clay, will become so indurated and compact as almost to lose its slaty peculiarity, Argillaceous, or earthy limestone, will become granular and crystalline, like the white marble of the statuary. The clays of the coal formations will appear like flinty or jaspery slate. Coal is turned into anthracite, or stone-coal; and anthracite into coke. Chalk becomes crystallised marble; which has been verified by a chemist who applied intense heat to chalk, sealed in a gun-barrel. Thus, then, it is seen that the clayslate used in roofing houses, is nothing but clay that has been subjected to strong heat under great pressure. thick beds of stratified gneiss, which is only granite worn away by water, to be deposited on a bottom of granite, you can imagine that the subterranean heat might acquire such intensity as to melt the granite crust under the gneiss afresh. This fresh fusion would rise to reach the lower beds of the overlying gneiss, and to penetrate them so thoroughly, as almost to destroy completely, all trace of the original lines of their stratification, and make them to appear as if they had never been under the action of water. Keep in mind that these changes in the character of altered rocks is not produced by heat alone. Volcanic action, in what may be called recent and modern epochs of geological time, assists us in studying the character of Plutonic action in more remote ages. It is well known that volcanoes send forth immense volumes of heated gases, which disengage themselves from melted matter, and struggle to make their way from the enormous pressure which overlies them. They maintain this effort for weeks, months, and years. When, therefore, fused granite or porphyry is burning, boiling, and heaving under great pressure, and containing powerful gases which cannot escape, these gases will act upon the crust above; and, when they are near porous rocks, they will pass through them with great facility, and, in passing, greatly modify them. It is true that we can study these phenomena only as they are observed on the surface of the earth; but it is clear that as gaseous fluids have altered the upper surface of the rocks, and as these fluids could only come from subterranean sources, they Fig. 7. Though these kinds of alteration are remarkable, still greater ones may have been produced in proportion to the greater intensity of the fusing heat; or according to the length of time in which the action of heat continued. There are, for instance, in the extreme south of Norway, sedimentary rocks penetrated by a large mass of granite, which must have protruded itself in a state of fusion. All about the mass of granite, the sedimentary beds are altered to the distance, from the once melted matter, of from fifty to four hundred yards. Before this protrusion took place, the shale or the schist consisted of green and chocolatecoloured layers of sediments; but the fused granite has changed these into ribboned jasper, like those which are found in the pebbles at Aberystwith, in South Wales,-specimens in which each stripe faithfully repre The dislocation of sedimentary strata by eruptive rocks. sents the original lines in which their various clays were deposited. The limestone of the neighbourhood, which was originally of an earthy texture, and of blue colour, as it is still found at a distance from the granite, is become white granular marble. It is also remarkable that both the slate and the limestone of that rock contain garnets, and ores of iron, copper, lead, and silver. In Cornwall, also, the fused granite has protruded veins into a rock, which the Cornish miners call "killas," a coarse argillaceous or earthy schist or slate,-a rock which has been altered by the heat of the fused matter, into hornblende schist. This operation is well developed both at St. Agnes, and St. Michael's Mount in the Bay of Penzance. These and a thousand similar instances prove that powers exist in nature which are capable of transforming sedimentary and fossiliferous rocks into crystalline strata. It has been intimated that in altering rocks, heat not only changes their appearance or aspect, but also gives them a new mineral character, and causes them, in some instances, to become identical with the melted rock which has changed them, though they themselves have not been meited. Chemists have proved by experiment, that a rock need not be perfectly melted before its component parts will re-arrange themselves, that is before they crystallise, or take a new mineral character. Sedimentary rocks, therefore, may be completely altered, without having the lines of their stratification obliterated. This theory will help you to understand a phrase often used by geologists, when they speak of "one rock passing into another," and that by imperceptible gradation. If you imagine E must have made their way through the entire crust, from the deep reservoirs below into the open air. Other alterations of strata will be more fully considered when we come to the subject of metamorphic rocks, and to the influence of volcanic action in the B protrusion of trap and basalt. The Plutonic changes, just alluded to, are mentioned now, only to illustrate one of the operations of heat on the early crust of the earth. In fig. 6, while the lower portions of the sedimentary beds D E are represented, by darkened lines, as having been altered either by heat or by gases, the altered strata still retain their original relation to the beds that have not been altered. There are, however, innumerable instances in which stratified beds, whether altered or not, have been completely disturbed and dislocated, as represented in fig. 7. A thousand instances are found, in which the strata have been broken through and tilted up, so that what was deposited horizontally appears now with their lines of stratification highly inclined; sometimes, almost perpendicular; at other times perfectly vertical; and, in some instances, quite inverted. Sections of vertical position you may find at Alum Bay, in the western end of the Isle of Wight; and, at Whitecliff Bay, in the eastern end of it. The same also may be seen near Welshpool, in North Wales, where PowIS CASTLE is built upon Silurian strata almost perfectly vertical. In fig. 7, A B is the earth's crust. c D, the sedimentary rocks resting on it. F, a dislocated portion of the altered beds B, and separated from them by the eruptive rock &, which has been thrown up to the earth's surface by the subterranean heat H. The study of fig. 7, will help you to apprehend the nature of geological reasoning. Suppose that a geological student travels from c to a, along a sedimentary rock. At a he comes to a rock of a different mineral character, and may be in difficulty to account for it. As he walks over F, or passes alongside of it, and has the face or section of F on his left hand as he walks towards d, he may not understand the new rock, till he comes to b. Here he finds the Plutonic rock G, say granite or porphyry, evidently of igneous origin. He goes over, or by the side of a, till he comes to c, where he finds the same rock LESSONS IN FRENCH.-No. XIV. RELATIVE PRONOUNS (§ 38). 1. QUI, used as nominative, may relate to persons or to things:Les fleurs qui sont dans votre jardin. The flowers which are in your garden. 2. Qui, used as the object of a verb, can only be said of persons. It is used interrogatively with or without a preposition: Qui votre frère voit il ? Whom does your brother see? De qui parlez vous ce matin ? Of whom do you speak this morning? 3. Que may be said of persons or things. It can never be understood, and must be repeated before every verb [Sect. 18. 1]. Les personnes que nous voyons. The persons whom we see. The languages which we learn. Arriv-er, 1. to arrive. Habillement, m. dress, Plaisir, m. pleasure, Linge, m. linen. Soulier, m. shoe. Monsieur, m. gentleman. Vrai, e, true. 1. Qui connaissez vous? 2. Nous connaissons les Hollandais dont vous nous parlez. 3. Quelles leçons apprenez vous? 4. Nous apprenons les leçons que vous nous recommandez. 5. Ce que je vous dis est il vrai. 6. Ce que vous nous dites est vrai. 7. De qui nous parlez vous? 8. Nous vous parlons des Ecossais qui viennent d'arriver. 9. Savez vous qui vient d'arriver? 10. Je sais que le monsieur que votre frère connait vient d'arriver. 11. Vos soeurs que font elles? 12. Elles ne font presque rien, elles n'ont presque rien à faire. 13. Que mettez vous dans votre coffre? 14. Nous y mettons ce que nous avons, nos habillements et notre linge. 15. N'y mettez vous pas vos souliers? 16. Nous y mettons les souliers dont nous avons besoin. 17. De quoi avez vous besoin? 18. Nous avons besoin de ce que nous avons. 19. Cet enfant sait il ce qu'il fait? 20. Il sait ce qu'il fait et ce qu'il dit. 21. Ne voulez vous pas le leur dire? 22. Avec beaucoup de plaisir. 23. Faites vous ce que le marchand vous commande? 24. Nous faisons ce qu'il nous dit. 25. Il parle de ce dont vous parlez. EXERCISE 60. 1. Have you what (ce dont) you want? 2. We have what we want. 3. Is the gentleman whom you know here? 4. 4. Ce que is employed for that which, or its equivalent what: The lady of whom you speak is here. 5. Is she just arrived? Ce que vous apprenez est utile. 5. Que answers to the English before a verb : Que pensez vous de cela? That which you learn is useful. What do you think of that? [Sect. 25. 2.] 6. She is just arrived. 7. Do you know that 6. Quoi, when not used as an exclamation, is generally pre- Do you know what you say? 16. I know what I say, and ceded by a preposition, and relates only to things: De quoi voulez vous parler ? Of what do you wish to speak? 7. Lequel, m. laquelle, f. lesquels, m.p. lesquelles, f.p. which, or which one [Seet. 17. 6], or which ones, relate to persons or things. They may be preceded by a preposition :Lequel avez vous apporté ? Duquel parlez vous? Which one have you brought? 8. Dont, of which, or of whom, whose, may relate to persons or things, in the masculine or feminine, singular or plural. It can never be used absolutely, and must always be preceded by an antecedent. It is preferable to de qui or duquel, &c. Les fleurs dont vous me parlez. The flowers of which you speak to me. 9. PRESENT OF THE INDICATIVE OF THE IRREGULAR VERBS. Tu dia, Il dit, Nous disons, Vous dites, Ils disent, what I do. 17. Do you know the Scotchman of whom your |