Imatges de pągina
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stratified rocks can be determined; these are now generally admitted and recognised are, superposition, mineral character, and by geologists. These are so well summed the organic remains contained in them; up by Mr. Trimmer in a recent work and these have been taken as the basis of (Practical Geology) as to present in a few classification by most geologists, however words the present condition of the science, widely they differ as to their nomencla- stripped of all speculation and theory. The ture, or views of the real age of these for- following abstract is principally derived mations. Thus Lehman, in 1759, divided from this source.-Rocks are still forming, them into primitive and secondary; the under the agency of fire and water, in the first containing no organic remains or frag- same manner as in times past. The crust ments of other rocks; and the latter com- of the earth, as far as examined, presents posed of the fossiliferous strata. Taking its materials in a determinate order of this theory as a basis, Werner proposed to superposition; the lower consisting of introduce a third class under the name of crystalline masses which are not stratified, transition, for a group of rocks having the and which not only frequently pierce crystalline characters of the primary, and through the Superimposed beds, but have at the same time containing organic re- produced alterations in these beds, where mains. In 1832, Mr. Conybeare proposed they came in contact with them, only atto name these strata from their position tributable to the action of heat. These alone, but from various causes his system was not generally adopted; and the same may be said of that of Mr. De la Beche in 1830, though it is much more definite, and better adapted to practical purposes. In the present condition of the science, stratified rocks are generally viewed as divided into primary, lower secondary, upper secondary, tertiary, and modern, all of which are variously subdivided by geologists according to their respective views, but which it would be impossible to notice in this place. As regards the origin of the primary strata, the theories have been very various; but it is now generally admitted that they all result from the action of both water and fire; though much difference of opinion exists as to the mode of action, and the epochs at which the changes occurred. All the other strata being fossiliferous, present definite characters in their included remains, and thus have enabled geologists to arrive at much more correct calculations as to their relative age; and it may be assumed as demonstrated that the succession of fossiliferous rocks maintain the same relative position to each other in all parts of the world, thus showing that analogous causes have produced analogous results wherever they have been called into action. -It must at the same time be confessed that, although a vast mass of facts have been collected, and most learnedly brought to bear on this or that theory, the attempts made to connect the laws of phenomena with those of causation are all open to objections, and stronger proofs than any hitherto adduced are required before they are generally admitted, and before a clear and connected knowledge of the history of the changes in the crust of the earth can be arrived at. There are, however, certain facts and inferences from them, which

granitic rocks are overlaid by crystalline strata, which are destitute of organic remains, but showing traces of having been deposited as a sediment, and are generally supposed to be aqueons deposits altered by heat; but the exact mode and amount of this change are still matters of controversy. The next strata in the ascending series abound in animal and vegetable remains; they are co-extensive with the earth's surface, and are very thick. The lowest of them is the oldest, and the uppermost the most recent. They are divisible into many groups, according to the groups of organic forms they contain. The greatest differences exist between those groups which are derived from the extremes of the series; and on the other hand, the greatest similarity between those which are found in strata which approximate in the order of succession. There are local diversities ably pointed out by Lyell and other geologists which must always be taken into account. These, however, are far more frequent in the newer than in the older deposits. - Almost all geologists now agree that an indefinite but vast lapse of time must have been required for these deposits to have been made, and that the few thousand years embraced in human records are as nothing compared with those incalculable periods during which the various strata composing the crust of the earth have assumed their present form. It has been clearly shown that these formations have been the result of gradual or successive operations; that deposits of strata have occurred; that these strata have been elevated, variously frac tured, contorted and acted upon by subterranean forces, altered by the action of fire, again depressed, and other deposits made, and the whole elevated again above the

GEOLOGY-GEOMETRY.

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waters. Another point universally conceded | mains have not been yet found in or below is, that the temperature of the earth in- any of these diluvial deposits. The wricreases in a progressive manner towards ters referred to, appear to think that this its centre; and hence it is supposed, if the period was one of intense cold, and that same fact holds good to great depths, that the temperate regions of Europe, and, in every thing must be in a state of fusion at fact, wherever unstratified gravel is found, a few miles below the surface. It has were covered with ice, as Greenland now been remarked by all geologists, that the is. This glacial theory was first broached organic remains of the older deposits indi- by Agassiz from observations made during cate a high but gradually decreasing tem- many years in Switzerland, which led him perature in northern latitudes, at the time to the conclusion that the vast glaciers of they were destroyed; but no satisfactory that country were not extending, as was explanation has yet been afforded of the supposed, from the tops of the mountains change that has taken place. All which is to the plains, but were the remains of still generally admitted, is that this change has vaster masses, which had covered the been gradual. It is true that considerable whole face of the country. Further obdifferences of temperature exist in the servations in other countries confirmed him same parallels of latitude, from the influ- in this idea; and the investigations of Mr. ence of local causes; but these differences Lyell in this country have led to the same are scarcely sufficient to have been the conclusion.-One of the most certain facts origin of the high temperature towards the of geology is, that man and his contempopoles in an early state of the world. Mr. rary species are but recent inhabitants of Lyell, however, proposes this solution of the earth. This is explicitly confirmed by the problem, or that it was owing to the the only book that contains the early hispreponderance of land towards the equator, tory of our race, and which is confined in and of ocean to the north and south.-The its purport to that, and hence ought not to changes that have occurred from the for- be considered as an account of what ocmer condition of the globe, or of its parts, curred prior to the creation of human beto its present state, have all been gradual, ings. But other records exist bearing the as is plainly indicated by the fossils found imprint of the same great power that called in the different strata. Breaks occur, and man into existence, which, in giant chalinks, indeed, are wanting; but when the racters, speak of ages so long anterior to observations of geologists are more extend- the present epoch, that the mind becomes ed, these may be found. Of the former bewildered in endeavouring to affix dates periods, that of the tertiary, as might be to them. supposed, most closely approaches the one now existing. The organic bodies found in the rocks of that epoch are more diversified than in those of the secondary age, and remains of the higher animals become numerous, and according to the age of the deposit, are more or less closely allied to living species. Thus, whilst in the older tertiary, extinct genera are common, in the newer they are replaced by extinct species of existing genera; the passage, however, as just stated, was gradual, for it is found that mollusca, identical with those now living in the adjacent waters, co-existed in the same region with extinct species, and even genera of mammalia.-Anterior to the present epoch, but posterior to the tertiary period, occurred a state of things which has been ably investigated by Agassiz, Buckland, and Lyell. This is what may be termed the erratic block, or boulder period, during which marine currents of great force, extent, and continuance, appear to have passed over a large portion of the earth's surface from the north. There is no evidence to show that this occurred since the creation of man, as human re

GEOMETRY* (Descriptive); a term first employed by Monge, and since by mathematicians generally, to express that part of their science which consists in the application of geometrical rules to the representation of the figures, and the various relations of the forms of bodies, according to certain conventional methods. It differs from ordinary perspective, inasmuch as the design, or representation, is made in such a manner that the exact distance between the different points of the body represented can always be found, and consequently all the mathematical relations resulting from the form and position of the body may be deduced from the representation.-Sculpture, architecture, painting, and all the mechanical arts, the object of which is to give to matter certain determinate forms, borrow from descriptive geometry their graphical procedures, by the aid of which all the parts of an object are faithfully represented in relief, before the object itself is executed. But it was chiefly in consequence of its application to civil and military engineering, and to fortification, that this branch of geometry re

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GEOMETRY-GERMANY.

ceived a distinctive appellation, and was considered of so much importance as to form one of the principal departments of study in the polytechnic school of France. -The best systematic treatises written on the subject are those of Monge, Hachette, Vallée, and Leroy. A good general idea, however, may be obtained from the small work of Lacroix, entitled "Complément des éléments de géométrie."

GERANDO (baron de) was, in 1819, appointed to a professorship of administrative law, the expediency of creating which he had himself suggested to the government. It was, however, suppressed two years afterwards. He had been elected a member of the Institute, in the class of the moral and political sciences; and on the suppression of this class, he became a member, in 1810, of that which, in 1816, received the name of the Academy of Inscriptions and Belles Lettres. Again, on the institution, in 1832, of an Academy of the Moral and Political Sciences, a seat in it was assigned to him. And he is also a member of most of the learned societies of Europe. He was one of the founders of the Society for the encouragement of the National Industry of France, of that for the elementary instruction of the children of all classes of the community, and of that also for the promotion of Christian morals; and he was instrumental to the establishment of savings' banks. He was, besides, one of the most active managers of the institution for the deaf and dumb, as well as of various of the hospitals and other charitable establishments of the capital. In addition to the works, already mentioned, of which he is the author, he has published an essay, styled "Le visiteur du pauvre," a treatise "De l'éducation des sourds-muets de naissance" (2 vols. 1827),-another entitled "Institutes du droit administratif français" (1829), and lastly, a work with the title "De la bienfaisance publique" (4 vols. 1839).

GERARD* (Count). After the revolution of July, he was entrusted, first by the provisionary government, and subsequently by Louis Philippe, with the department of war, an office which, however, he held only during three months. In August 1830, he was promoted to the rank of a marshal of France, and in August of the following year, was appointed to command

States.

Austrian dominions in Germany. Prussian do. do.

Bavaria...

Hanover

Wurtemberg

Saxony

the army destined to besiege the citadel of Antwerp. In October 1832, he was created a peer. On the 18th of July 1834, he once more became minister of war, and was at the same time appointed president of the council of ministers. But, as before, in little more than three months he quitted the ministry. He succeeded Marshal Mortier, on the death of the latter, as chancellor of the legion of honour; and in December 1838, on the death of Marshal count Lobau, he was invested with the office of commander (commandant gênéral) of the national guard of the department of the Seine.

GERARD* (Francis). Among the latest productions of this distinguished painter may be mentioned "Napoleon in his closet" (1831); "The plague at Marseilles" (1832); a full-length portrait of Louis Philippe; "Louis Philippe accepting the lieutenantgeneralship of the kingdom;" and the portrait of General Hoche (1836). He died, January 11th 1837.

GERMAIN (Sophie), born at Paris in 1776, made, at a comparatively early age, an extraordinary progress in the mathematical sciences, and, in 1816, obtained the prize of the Academy of Sciences for a memoir on the vibration of elastic laminæ. She pursued this subject further in her "Recherches sur la théorie des surfaces élastiques” (1820), in another memoir presented to the Academy (1826), and in an article in the "Annales de physique et chimie" (1823). During the revolution of the three days, she was quietly engaged at Paris in the preparation of a memoir on the curvature of surfaces, which was, when finished, inserted in Crelle's Journal of the Mathematics. She died in 1831, of a cancer. Distinguished as she was by her acquirements and performances in the exact sciences, her attention had been far from being exclusively confined to them, but was, on the contrary, directed, in no inconsiderable degree, also to natural science, geography, history, and the speculations of philosophy.

GERMANY. The following table, exhibiting the extent in German square miles (each of them equivalent to 21.17 Eng lish sq. m.), with the population of the several states of the Germanic Confederation in the year 1840, is copied from Berghaus' Geographical Almanac for 1841.

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The same states had, in 1816, 30,164,390 inhabitants; so that their increase of population, in the following 24 years, amounted to 8,954,510, or to very nearly 30 per cent.

We give also a list of the 12 largest towns of Germany, with the amount of their population (1840) annexed.

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350.097 265.394 120,000 102,918 93,435 8-,869 75,551

69,051

54.822

51,344 47,514

11,385

........

39,118,900

Hesse-Cassel, Nassau, and Luxemburg (27,231 men); the 10th, by Hanover, Brunswick, Holstein, the two Mecklenburgs, Lubeck, Hamburg, and Bremen (34,717 men); and the 11th by the other minor German states (11,152 men); the whole amounting to 320,102 men.

The two great internal improvements which have taken place in Germany of late years are, first, the gradual extension of the Prussian Customs' Union, or “Zollverein," until it has at length bestowed the benefits of an uninterrupted freedom 69,523 of commerce throughout the whole extent of the vast region from Aix-la-Chapelle, on the borders of the Netherlands, eastward to Tilsit, on the confines of Russia, and from Stettin and Dantzic, southward to Switzerland and Bohemia; and the introduction of railroads, which here, as elsewhere, have had the effect of multiplying in an extraordinary degree the transit of both persons and commodities from one part of the country to another. In relation to the Customs' Union, the reader is referred to the article Prussia in this volume. The following are some of the most important points of information concerning the railroads actually constructed, or in process of construction:Austria. 1. From Budweis to Lintz and Gmünden. It was begun in 1825, was completed as far as Lintz in 1832, and to Gmünden in 1836. It has only a single track; and the cars are drawn over it by horses. Its length from Budweis to Lintz

The quota of troops which the several German states are required to furnish, in the event of a war, to the army of the Confederation, is the same at present as it was when the Confederation was formed, in 1815, with the exception (an alteration made in 1831) that, in the case of some of the smallest states, it is to consist of infantry only, the cavalry and artillery required to act with it being furnished by Austria and Prussia, and with the exception also of the army being divided into 11 instead of 10 corps. The 1st, 2d, and 3d corps are composed of Austrians (94,822 men); the 4th, 5th, and 6th of Prussians (79,234 men); Bavaria furnishes the 7th corps (35,600 men); Wurtemberg, Baden, and Hesse-Darmstadt, the 8th (37,346 mcn); the 9th is furnished by Saxony,

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is about 80 miles, and from Lintz to Gmünden, about 42 more; and its cost was about 1,637,000 dollars. The projectors of this road intended to connect, by means of it, the Danube with the Elbe, and by help of these rivers to establish an easy communication, through the interior of Europe, between the German Ocean and the Black Sea. Thus far, however, it has chiefly served for the conveyance of the salt of Lower Austria in the direction of Bohemia, and as a means of supplying the steamboats on the Danube with the coal of the latter kingdom. 2. From Prague to Lahna. This is another link in the great chain of communication just mentioned. It was constructed by a joint stock association, having the privilege of the road granted them for a period of 50 years, but is the property at present of the prince of Fürstenberg. It has, like the former, only a single track, and the conveyance likewise is by horse-power. Its length, we are informed, is about 36 miles, and it was opened in the year 1830. 3. From Vienna to Gloggnitz and Grätz. This railroad is one of the most travelled on the continent of Europe. From 5000 to 6000 passengers are said to be conveyed on it daily. The section of it between Vienna and Gloggnitz was begun in 1839, and opened in 1842. It is 45 miles long, and cost about 5,000,000 dollars. There are two tracks upon it as far as Neustadt. It is the commencement of the intended great public line of railway communication between Vienna and Trieste, which is now in active progress.-4. A railroad extending from Vienna northward, in the direction of Moravia. Begun in 1836, it is now finished as far as Leipnick. The first section of this road, the only one which has two tracks, reaches from Vienna to Genserndorf; and from that place a branch goes off towards Stockerau, which is the commencement of a great line of communication, to be constructed at a future day, between Vienna and Munich, along the Danube to Lintz, and thence across the country to the Inn. From Genserndorf the road proceeds to Leipnick by way of Lundenburg and Prerau. At the former of these towns, a branch goes off to Brünn, and at the latter another to Olmütz. At a meeting of the stockholders, in October 1843, it was resolved to extend the road from Leipnick to Oderberg, where it is to connect itself with the Prussian railroad of Upper Silesia. Railroads intended to connect Brünn and Olmütz with Prague are now also in process of execution. The northern railroad of

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which we have been speaking, will, including its several branches, have a length of about 190 miles; and the estimated cost is 8,000,000 dollars. - Prussia. 1. From Berlin to Potsdam. This road, intended for two tracks, has as yet only one. It is about 17 miles long, and has cost about 1,000,000 dollars. It is intended to be ultimately carried on to Magdeburg.2. From Berlin to Coethen, a distance of about 96 miles. It has cost a sum of 4,230,000 dollars.-3. From Berlin to Stettin. This was commenced in 1840, and opened as far as Angermünde in 1842, and through to Stettin in the following year. Its length is 87 miles, and its cost 2,350,000 dollars. And although constructed for two tracks, it has only a single one, like most of the other railroads in Germany.-4. From Berlin to Frankfort on the Oder. Length, 52 miles; and cost, very nearly 2,000,000 dollars.-5. From Leipsic to Magdeburg. This line of railroad is 75 miles in length, and was completed with one track in August 1840. The second track was laid in 1842. The entire cost of the road was 3,100,000 dollars. It passes through Halle and Coethen.-6. From Breslau to Oppeln, Liegnitz, Freiberg and Schweidnitz. railroad from Breslau to Oppeln was opened as far as Ohlau in May 1842, as far as Brieg in August 1842, and has been in full operation along its whole extent since the month of May 1843. Its length is 51 miles; and it cost somewhat above 1,000,000 dollars. The line of road from Breslau to Liegnitz is the first section of that which is destined to connect Breslau with Frankfort. It was begun in 1843. It has a length of 41 miles; and its prolongation into the kingdom of Saxony has been determined upon in a special convention concluded by the Prussian and Saxon governments at Berlin in July 1843. The line from Breslau to Freiberg and Schweidnitz was opened as far as the former of these places, a distance of 36 miles, in October 1843. This, with the branch from Jauernick to Schweidnitz, a distance of 5 miles, were constructed at a cost of 1,330,000 dollars.-7. From Magdeburg to Brunswick, and branches. This road is divided into several sections. The first connects Magdeburg with GrossOschersleben, whence there is a branch to Halberstadt. The second section extends from Oschersleben to Wolfenbüttel, where it unites with the railroad from Brunswick to Harzburg. This last road has been constructed by the government of Brunswick. The whole line was opened in

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