THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
LITHOGRAPHS: 
 
 A SERIES OF 
 
 FOUE LECTUKES ON GEOLOGY, 
 
 DELIVERED BEFORE 
 
 Ijtoroich (Siptojical 
 
 And published under their auspices, 
 
 JOHN E. TAYLOR, 
 
 u 
 
 Hon. Sec. Horfoltb datalogical otictg, #c. 
 
 AUTHOR OF 
 
 "COAL MEASURES OF GREAT BRITAIN;" "GEOLOGICAL ESSAYS, AND 
 SKETCH OF THE GEOLOGY OF MANCHESTER AND NEIGHBOURHOOD," ETC. 
 
 Speak to the earth, and it shall teach thee :" JOB xii, 8. 
 
 LONDON: 
 HAMILTON, ADAMS, AND CO.; 
 
 NORWICH: FLETCHER AND SON. 
 
PEEFAOE. 
 
 THE following Lectures I had the honour to deliver 
 to the members of the Norwich Geological Society 
 and their friends in the Norwich Museum towards 
 the end of last winter. At the request of the 
 members, and encouraged by the manner with which 
 the Lectures were received, I determined to publish 
 them. Two of the Lectures embrace collateral sub- 
 jects, whilst the others are purely geological. I have 
 endeavoured throughout to combine as many facts 
 with just such common sense theories as explain 
 them, and, in doing so, to render them as popular 
 and, at the same time, as useful as I could. 
 
 J. E. T. 
 
 Norwich, 
 October 21st, 1866. 
 
CONTENTS. 
 
 LECTUEE I. 
 
 Introduction Mr. Page on the relation of aqueous and igneous 
 forces The'two great divisions of igneous rocks Ideal 
 section of ditto History of discovery in ditto Nebulous 
 hypothesis Primitive rocks Application of microscope 
 Mr. Sorby' s experiments Increase of heat in mines 
 Denudation of granitic rocks Varieties of granite 
 Relative ages of granitic outbursts Varieties of por- 
 phyry Volcano of Jorullo Thickness of the earth's 
 crust The earliest formations Theory of geological 
 succession Varieties of volcanic rocks Basaltic dykes 
 and outbursts Alterations of surrounding strata by 
 ditto Age of dykes Greenstone The relation of 
 igneous outbursts to metal veins Original commixture 
 of primitive bodies Metals dissolved in sea- water Gold 
 in Philadelphia clays Segregation of metals Cornish 
 veins Lead mines of Derbyshire Crystallization of 
 metals Mineral veins and igneous rocks Sublimation 
 of metals by recent volcanoes Volcanic eruptions 
 Ditto in geological epochs Conclusion . pages 1 to 32 
 
VI CONTENTS. 
 
 LECTURE II. 
 
 Dr. Mantell's remarks Study of physical geography Atmos- 
 pheric action Evaporations of Atlantic Rainfall 
 Mud carried into the sea by great rivers The sea, the 
 mother of new lands Alternations of ocean bottom 
 The Gulf-stream Waste of land around the British 
 coasts Rev. John Gunn on waste of Norfolk coast 
 Holland Goldsmith's "Traveller" Formation of new 
 lands Deep sea depositions Layers on the bottom of 
 Lake Superior Coral reefs, &c. The Pacific Islands 
 Plutonic agencies, elevation and depression of surfaces 
 Upheaval of plains of Jorullo Formation of volcanic 
 islands Lava streams Influence of geographical know- 
 ledge on geology The influence of the Gulf-stream 
 Extinction of animals in historic times Creation of 
 species Denudation of formations . . pages 33 to 67 
 
 LECTURE III. 
 
 Idea of the ancients Relation of the natural sciences Pro- 
 vince of the geologist Relation of geology to astronomy, 
 chemistry, &c. Progress of discovery in latter sciences 
 Geographical discovery and natural history Legends 
 and folk-lore connected with geological phenomena 
 History of geological discovery Lehmann's classifica- 
 tion Debates of Werner and Hutton Formation of 
 geological societies Authorities in various departments 
 
CONTENTS. Vll 
 
 LECTURE III. (continued.) 
 
 of geology Lyell's classification Definition of rocks 
 Ditto of fossils Thickness of aqueous rocks Phenom- 
 ena of animal instincts and habits seen in rocks 
 Enormous ages of deposits Nomenclature of rocks 
 Eelation of fossils to formations Continuity of life 
 Apparent breaks in succession of ditto Occurrence of 
 connecting links Mineral characters of formations 
 The manner of identifying rocks Smith and Cuvier on 
 fossils Owen on distribution of ditto Geological anal- 
 ogy by Professor Silliman Conchological and botanical 
 provinces Natural sections . . . pages 68 to 112 
 
 LECTURE IV. 
 
 Abundance of gravel, sand, and clay sections Recent interest 
 attached to these deposits Eelation of glacial beds to 
 tertiary strata Common appearance of a sand pit 
 Sand pit at Stoke Cause of absence of shells in sand 
 beds Old Bed Sandstone conglomerate in the Isle of 
 Man Drift beds in North of England Norfolk boulders 
 Evidence of cold climate Arctic shells in drift beds 
 Scratched boulders Their foreign origin Glaciers of 
 the Alps and of Greenland Agency of icebergs Appear- 
 ance of London clay Fossils of ditto, contrasted with 
 those of the drift beds Evidences of increasing cold in 
 the Coralline, Red, and Norwich Crags Ditto supple- 
 
Vlll CONTENTS. 
 
 LECTURE IV. (continued.) 
 
 mented by overlying drift beds Extinct glaciers of 
 Great Britain Formation of lake basins The Norfolk 
 forest bed Arctic plants, the remains of a former flora 
 Deep sea shells Introduction of Germanic .flora 
 Extinct mammalia of drift beds Cave breccias Valley 
 gravels and flint implements Former prolongation of 
 Swiss glaciers Hot winds of the Sahara Former 
 Saharan ocean Evidences of design in drift beds 
 Conclusion pages 113 to 135 
 
LECTUEE I. 
 
 THE IGNEOUS EOCKS AND FORMATION 
 OF METALLIFEROUS VEINS. 
 
 THE four primitive elements of the ancients, earth., 
 air, fire, and water, have greatly changed their position 
 since the time when they occupied the whole category 
 of the natural philosopher. Instead of assigning to 
 any of them the dignity of an "element," modern 
 science has reduced three to the state of chemical and 
 mechanical compounds whilst the fourth, instead of 
 being an "element" at all, is proved to be but the 
 heat evolved during chemical change. And yet, one 
 branch of modern science, geology, has restored to their 
 ancient importance at least two of these so-called 
 elements although it agrees with its associates in 
 ranking them, not as primitive bodies, but simply as 
 agents. Of these two, whose importance has secured 
 to them a place in our proverbs as " good servants, but 
 bad masters," in the present lecture I purpose to select 
 heat, and to lay before you the influence which it has 
 
 B 
 
2 POPULAR GEOLOGY. 
 
 exercised in modifying and changing the crust of the 
 globe. 
 
 Both the above-mentioned agencies have been em- 
 ployed, more than any other, in building up the earth's 
 rocky beds. " Between these two great forces "says 
 Mr. Page, "the aqueous and the igneous the crust 
 of the earth is ever held in habitable equipoise and 
 never-ending variety of superficial aspect. As the 
 former tends to waste and wear down, and to carry 
 the eroded material to the bottoms of lakes and estu- 
 aries, there to be spread out in layers of varied con- 
 sistency, so the latter as incessantly strives to elevate 
 and reconstruct here throwing up the sea-bed into 
 new islands, there disrupting and undulating the solid 
 crust, and anon casting forth from volcanic craters new 
 rocks and rocky compounds." 
 
 The igneous rocks, so called from their fiery origin, 
 are classed under two divisions viz., the Plutonic arid 
 the Volcanic. The volcanic rocks include the various 
 traps, greenstones, basalts, obsidians, &c., all of which 
 have been formed on or near the surface of the earth ; 
 many of the trap rocks, as will shortly be shown, have 
 flowed in a molten state over the old sea-bottoms 
 while in ancient times, as at the present day, lava- 
 streams ran down the mountain sides and flowed into 
 rivers and lakes, and sometimes even into the sea. 
 The plutonic rocks include the various porphyries, 
 syenites, granites, &c., which could only be formed at 
 great depths below the surface, and under the influence 
 of immense pressure. This pressure, caused by thou- 
 
POPULAR GEOLOGY. 
 
 sands of feet of overlying rock which have been piled 
 above the viscid, molten mass, has prevented the escape 
 of vapours and gases, and thus caused it to crys- 
 tallize in a heterogeneous condition. Now, although 
 the rocks of the volcanic class have doubtless risen, 
 some of them, from as great depths as the plutonic., 
 the difference in appearance is mainly due to the cir- 
 cumstances attending their formation. Thus, suppose 
 an immense fissure extended from the surface of the 
 earth to the fiery reservoir in its interior; and that 
 through this the molten matter below were to be ejected ; 
 if we could arrest the process whilst the fissure was 
 filled, and cause the whole to cool, so that it could be 
 laid open to view as a single section, we should find in 
 the descending order as follows : First near and at 
 the surface, the rocks would be of the same kind as 
 those emitted from modern volcanoes ; a little deeper 
 they would exist as trap, basalt, or greenstone ; and 
 lower still these would be found gradually passing into 
 porphyries, such as greenstone-porphyry, &c. ; and, 
 still descending, at last we should meet with the true 
 granites. So that we see the chief modifications of 
 the igneous rocks have been pressure, heat, and the 
 circumstances which have influenced their cooling. 
 
 The history of discovery in this department of 
 geology would form an interesting volume. Towards 
 the end of the seventeenth century, Leibnitz pro- 
 pounded the theory of the earth having once existed 
 as a molten mass, previous to its being inhabited by 
 animals and plants. This theory, some time after, 
 
 E2 
 
POPULAR GEOLOGY. 
 
 gained ground from astronomical discoveries \ and the 
 more so when Sir William Herschel conceived the 
 hypothesis of the whole universe of matter having 
 once existed in a nebulous state, and, after a sub- 
 sequent condensation, formed globes and rings of 
 solid matter. This hypothesis agreed with the fact of 
 the planets and their satellites being of a spheroidal 
 form, and explained how the greater diameter of their 
 equators would be due to their revolving on their 
 axes, and so causing the matter, when in a viscid 
 condition, to aggregate at right angles to the poles. 
 This theory was afterwards damaged by the discovery, 
 that all the nebulae did not exist as cosmical masses' 
 of vapour, but that, with greater magnifying power, 
 they could be resolved into groups of stars. The 
 hypothesis of the earth's original condition held sway 
 for years ; and it is but fair to state that, at the 
 present time, there are some philosophers, of very high 
 standing, who are in favour of it.' ;t 
 
 Eut it was further argued by geologists, that, upon 
 the earth's cooling, an outer crust was formed, which 
 roofed in the fiery, molten nucleus ; and that this 
 
 * Vide Herbert Spencer's "Philosophical Essays," in which the 
 existence of cosmical masses as nebulas is defended with great 
 ability and logical accuracy. The existence of gaseous nebulae is 
 now a positive fact, as was proved by the experiments of Professor 
 Huggins in his lecture to the British Association this year. The 
 application of the spectrum analysis to astronomy has sufficiently 
 and clearly proved that the matter of the tails of comets and of 
 many of the nebulas are identical in composition. Indeed all the 
 discoveries of the spectrum go to indicate the common origin of 
 all the stars and planets which revolve in space. 
 
POPULAR GEOLOGY. 5 
 
 primitive rock, formed under such conditions, was 
 granite. It is not uncommon, in works published 
 within the last few years, to see this theory advocated 
 and set forth ; but I scarcely need tell you it is wholly 
 untenable, for geologists cannot tell which were the 
 primitive rocks. They can only arrive at the history 
 of the earliest sedimentary ones. These, however, 
 cannot have been the first formed, for they are com- 
 posed of the debris of earlier rocks, and there must 
 have existed ancient lands at the time of their deposi- 
 tion, or they could not have been formed by the usual 
 processes of aqueous wear and tear. I have already 
 adverted to the fact that granite could not be formed 
 on the surface, but that heat and pressure were neces- 
 sary conditions to its elaboration. 
 
 And, again, geology has shown that granite, instead 
 of being the primitive rock, is newer than many of 
 the fossiliferous ones that it belongs to rocks of all 
 ages, and is found traversing strata of every formation 
 up to the tertiary. It is doubtless also being formed 
 at the present day, but the thick covering of rock, 
 under which the process takes place, will have to be 
 denuded in subsequent ages, ere it can be exposed to 
 the light of day. As to the agency which has been 
 employed in its elaboration, from the times of Werner 
 to the present there have been conflicting opinions. 
 Werner and his disciples held that granite was the 
 result of a chemical precipitation from water, and was 
 consequently an aqueous rock. On the other hand, the 
 Huttonian school have always argued for its plutonic 
 
b POPULAR GEOLOGY. 
 
 origin, and have assigned as agencies in its production 
 the intense heat of the fiery reservoir in the earth's 
 interior. From the most recent discoveries, however, 
 it would seem that in this case, as in others of a 
 similar kind, the disputants will have to split the 
 difference, and combine their theories in order to 
 account for all the phenomena. The microscope had 
 done good service to geology in showing that many of 
 its stratified rocks had been formed through vital 
 agency, and were nothing more than accumulations of 
 foraminifera; but its recent application to the mineral 
 structure of rocks is quite modern, and has been pro- 
 lific in the most interesting results. Mr. Sorby was 
 the first to employ this instrument in such a manner, 
 and it has opened a wide field of speculation and 
 research. Now in granite, which is generally com- 
 posed of three ingredients, the quartz is often found 
 containing cavities, both visible to the naked eye and 
 microscopical, which are filled with a fluid, generally 
 water. A French chemist has shewn that molten 
 matter at a white heat requires its temperature lowering 
 very considerably before it can evaporate the water 
 which may be mechanically mixed with it. Now, as 
 we have seen, the granitic fused matter in the deep 
 laboratory below being wholly excluded from the air, 
 and, in a manner, hermetically sealed, would as it 
 gradually cooled enclose the water, which otherwise 
 would have been evaporated, in the cavities of the 
 minerals which enter into its composition. Further, 
 Mr, Sorby ^hows that crystallized matter which has 
 
POPULAR GEOLOGY. / 
 
 undergone igneous fusion has cavities in its crystals, 
 not containing water, but either stony matter, or glass, 
 and in many instances a total vacuum, owing to the 
 exterior cooling more rapidly than the interior of the 
 crystal. Hence he comes to the conclusion that in the 
 formation of granite the "proof of the operation of 
 water is quite as strong as that of heat, and, in fact, 
 that in the case of coarse-grained, highly quartzose 
 granite, there is so very little evidence of igneous 
 fusion, and such overwhelming proof of the action of 
 water, that it is impossible to draw a line between 
 them and those veins where, in all probability, mica, 
 felspar, and quartz, have been deposited from solution 
 in water." The fact of water taking a part with heat, 
 in the formation of this class of rocks, does not detract 
 from the theory that they are of igneous origin ; it 
 only shows that the water which has been employed 
 must have been intensely hot. Under the pressure of 
 several atmospheres, water can be made sufficiently hot 
 to melt lead ; and low down in the bowels of the earth 
 the water which has there entered into the composition 
 of granite may have been hotter still. Even the con- 
 stant action of the heated water of the Iceland geysers 
 is said to render the outside of siliceous stones quite 
 plastic and soft. What then must be the effects of 
 heated water and steam acting under immense pressure 
 upon a certain body of already heated rock? Mr. Sorby 
 himself states that in his opinion " the water associ- 
 ated with thoroughly melted igneous rocks at great 
 depths does not dissolve the rock, but the rock dissolves 
 
POPULAR GEOLOGY. 
 
 the water, either chemically as a hydrate, or physically 
 as a gas." Further, the interesting investigations of 
 this gentleman prove that the various kinds of granite 
 have been formed under different pressures of over- 
 lying rock, and by different quantities of heat ; but it 
 is probable that none of them became solid until the 
 temperature of the mass had cooled down to about 
 that of boiling water. Thus, the granites of the High- 
 lands indicate an origin beneath a pressure of twenty- 
 six thousand feet of rock more than those of Cornwall ; 
 so that while those of the latter seem to have been 
 formed beneath a pressure of forty thousand feet, 
 the granite rocks of the Highlands originated under a 
 pressure of as much as sixty-six thousand feet. 
 
 It is a well-known fact, that, as we descend in deep 
 mines, there is a gradual increase of heat. The ratio 
 of this increase varies according to the conducting 
 power of the rocks through which we may pass ; 
 although even this does not seem to be a general law. 
 The amount of increase is by no means uniform; some- 
 times it is as much as one degree for each twenty-four 
 feet of descent, and at others not more than one degree 
 for every one hundred and four feet. As a general 
 rule, Mr. Hunt states that the average rate of increase 
 is one degree for every fifty feet, in penetrating through 
 the first hundred fathoms, or two hundred yards ; for 
 the next hundred fathoms one degree for seventy feet ; 
 whilst, when the depth exceeds two hundred fathoms, 
 it is only one degree for every eighty-five feet of depth. 
 According to this formula, therefore, at the depth of 
 
POPULAR GEOLOGY. 
 
 fifty-three thousand feet, at which most of the granites 
 have been formed, the temperature would be about six 
 hundred and eighty degrees, Fahrenheit. It is evident 
 that all the rocks of the granite family must have 
 been formed, not after, but before, they reached the 
 surface ; consequently it follows that when such a rock 
 is exposed and seen contorting the strata around it, 
 vast masses, which once overlay it, must have been 
 denuded off in some of the geological ages, so as to 
 expose what was going on in the interior of the earth 
 perhaps at the very time when those missing beds were 
 forming. In Ireland there are extensive areas where 
 nothing but granite is found at the surface ; here we 
 have an instance of the wasting agencies of former 
 seas but what seas no geologist can tell ! In Devon 
 the same phenomenon occurs ; and in the Isle of Man, 
 in several places, a coarse syenitic granite is seen 
 bulging through the surrounding clay-slates changing 
 them into mica-schists and quartzose bands around the 
 places of contact. The Malvern hills have a nucleus 
 of syenite which was uplifted when in the solid state. 
 The igneous matter was first formed below and then 
 uplifted along with the beds which had been deposited 
 along the bottoms of the Silurian seas. In fact, there 
 is scarcely strata of any geological age which have not 
 their set of granite veins, and that do not give proof 
 of the denuding agencies to which they have been 
 subjected, and show whence the material for the for- 
 mation of beds of later ages has been derived. 
 
 Granite, which takes its name from the Latin 
 
10 POPULAR GEOLOGY. 
 
 granum, "a grain," is generally composed of from two 
 to four ingredients, viz., quartz, felspar, mica, and 
 hornblende, united in various proportions ; but it is 
 not necessary, in order that a rock should be a granite, 
 that all these four should be present. The quartz, 
 generally of a milky-white colour and a glassy appear- 
 ance, may be known from the other minerals by its 
 superior hardness and its capability of scratching glass. 
 Felspar, the mineral which generally predominates and 
 determines the colour of granite, is most commonly of 
 a dark red or fleshy tint ; although it occasionally 
 occurs in other colours. It is also so exceedingly soft as 
 to be scratched by the finger-nail ; and owing to the 
 predominance, more or less, of this mineral, depends 
 the durability of the mass in which it occurs, for when 
 very abundant, as in some of the red granites, it causes 
 the whole to decompose, and thus produces ivhat is 
 called the rotting of the rock. Mica is so well known 
 as scarcely to need a description, as every one is 
 familiar with the thin silvery-looking scales seen in 
 granite. Hornblende, which is always either of a black 
 or dark-green colour, if abundant produces a granite 
 rock varying from dark grey to black ; and when it 
 prevails to the exclusion of mica the rock passes into 
 syenite, which takes its name from occurring over very 
 large areas at Syene, in Egypt. By the prevalence of 
 hornblende and felspar, granite passes into greenstone ; 
 and if mica and quartz predominate, it will graduate 
 into a kind of mica-schist. In fact, M. Jobert sup- 
 posed mica-schist to be nothing but modifications of 
 
POPULAR GEOLOGY. H 
 
 the primitive granite; but his theory is no longer 
 tenable, as this rock is not peculiar to any forma- 
 tion. Besides the four common minerals I have just 
 named, there are others which enter into its compo- 
 sition, such as chlorite, talc, actinolite, steatite, &c. 
 The texture of granite is confusedly crystallized, owing 
 to the crystals having interfered with each other's shape 
 whilst they were forming. Sometimes these crystals 
 are found measuring an inch in diameter, whilst at 
 others they are so minute as to be scarcely visible. 
 Graphic granite occurs chiefly in veins, and generally 
 consists of felspar and quartz alone these two minerals 
 being crystallized in prisms, the cross-sections of which 
 give rise to an appearance not unlike the letters of the 
 Hebrew language whence the name of this variety. 
 Sometimes granite is found assuming a porphyry tic" 
 character, and has large and distinct crystals of felspar 
 imbedded in a granular base ; the pavemenirslabs of 
 the London streets are examples of this sort, and are 
 obtained from Cornwall. Nearer to us I may mention the 
 curb-stones in Post Office Street, Norwich, which are of 
 a similar kind of granite. Very often granite is seen 
 occurring in veins, which ramify into the adjacent 
 rocks. When this is the case, the rock is often meta- 
 morphosed at the point of contact, through the heat 
 which has accompanied the fused matter. Thus gneiss, 
 in many instances, is changed, in the neighbourhood 
 of these veins, into a kind of granite; limestone as- 
 sumes quite a crystalline character ; and clay-slate is 
 baked into hornstone. All such veins have been formed 
 
12 POPULAR GEOLOGY. 
 
 through the injection of the molten matter into fissures 
 and cracks which had previously existed in the solid 
 rock ; they are especially common in the earlier strata, 
 such as the clay-slates and mica-schists. Granite veins 
 have even been found ramifying through granitic 
 masses of older age ; showing that the original fused 
 mass had cooled and contracted through the loss of its 
 heat, so as to allow the newer fused matter to be 
 squirted into the cracks. At Heidelberg there are 
 three sets of veins of three different ages, all of them 
 differing in colour, grain, and peculiarity of mineral 
 structure and composition. According to Mr. Darwin, 
 the granites of the Cordilleras, South America, have 
 been in a fluid state since the tertiary period, as strata 
 of that age are seen contorted and upheaved by them. 
 It is not uncommon to find masses of granite divided 
 into joints, which are generally of such a regular form 
 as to give to the rock the appearance of stratification ; 
 this phenomenon, however, is nothing but a sort of 
 sub- crystallization of the mass subsequent to its ex- 
 isting in a viscid condition. 
 
 When the mica ingredient of granite is replaced by 
 talc, it is termed a talcose granite. It is through the 
 decomposition of this variety of rock that the Kaolin, 
 or China clay, of Cornwall, is produced upwards of 
 twelve thousand tons being annually exported from 
 that duchy to the potteries. Syenite is a true granite, 
 and generally contains four ingredients, viz., quartz, 
 'felspar, mica, and hornblende ; the mica commonly 
 existing in small quantities. In Cornwall there is also 
 
POPULAR GEOLOGY. 13 
 
 a granular mixture of quartz and felspar alone, which 
 occurs in veins proceeding from the parent mass, and 
 branching through the neighbouring rocks these veins 
 go by the name of "elvans." Granite is also found 
 graduating through syenite and greenstone into basalt 
 and other rocks of the trap family. This phenomenon 
 is common in Ireland where the veins which proceed 
 from the syenite take up the lime of the limestones 
 whiclt they traverse, and combine with it, at the same 
 time liberating the potash of the felspar. 
 
 Porphyry, which takes its name from the mineral 
 used by the ancients for the manufacture of vases, &c., 
 being of a purple colour, is nearly allied to granite. 
 It is rather a loose term, and is applied to any rock 
 having a compact base in which distinct crystals, 
 generally of a parallelogrammic form, are imbedded. 
 The base is generally felspar, and the imbedded mine- 
 rals are composed either of that mineral or of quartz. 
 Owing to the vagueness of this term, and the fact of 
 its conveying no idea of its composition to the mind, 
 the geologist generally associates porphyry with the 
 name of its base. This has given rise to the various 
 terms extant, such as claystone-porphyry, clinkstone- 
 porphyry, felspar-porphyry, pitchstone-porphyry, and 
 others ; each of the bases occurring under various 
 modifications of colour. Felspar-porphyry is by far 
 the most common, and occurs both in overlying and 
 interposed masses, sometimes having a columnar struc- 
 ture, and also as dykes traversing strata in the same 
 manner as trap. Trachyte is a felspathic.rock generally 
 
14 POPULAR GEOLOGY. 
 
 of a greyish colour, very coarse and rough; from 
 which circumstance it derives its name, trachus being 
 the Greek term for " roughness." This rock is apt to 
 decompose on exposure to the weather, but still is used 
 as a building stone in many localities Cologne cathe- 
 dral being built with it. It also contains crystals of 
 felspar, hornblende, augite, and even mica. There are 
 many other modifications of granite, such as serpentine, 
 diallage, &c. All these rocks are unfavourable to vege- 
 tation, and their localities may almost be known from 
 the bleak and sterile vegetation clothing the surface. 
 
 jSTow the heat which has been employed in fusing 
 the rocks of the foregoing class, and which has been 
 conducted away by the masses in their neighbourhood, 
 or else radiated into space, must have been very great. 
 Recent lava-streams which have been exposed in the 
 open air, have been ten years in cooling ; and the heat 
 which was emitted by the new volcanoes of Jorullo in 
 1759, was so great as to render the surrounding country 
 uninhabitable for the next fifty years. And yet, had 
 the earth cooled to any great extent by these successive 
 emissions, its contraction from such a cause would have 
 materially shortened the length of our day. Astrono- 
 mers, however, deny that any such circumstance has 
 taken place, and this has led many philosophers to 
 suppose that the fused matter emitted by volcanoes 
 and other agencies, is due to the oxidization of metals, 
 by the admission of water into the interior of the 
 earth. It seems more in keeping with all the circum- 
 stances to suppose the igneous fluidity of the earth's 
 
POPULAR GEOLOGY. 15 
 
 interior, and that the volcanic emissions and earth- 
 quake tremors are but the results of wisely-ordained 
 laws governing the state of our planet's molten mass, 
 and, in this manner, serving as safety-halves to conduct 
 away the force which would otherwise shatter and 
 fracture its crust, and perhaps cause it to explode in a 
 manner similar to that of the hypothetical planet 
 Pluto ! * 
 
 The thickness of the earth's crust is variously esti- 
 mated. Humboldt placed it at from thirty to forty 
 miles ; whilst Mr. Hopkins states, that, in his opinion, 
 the least thickness must be a fourth or a fifth of the 
 earth's radius ! It would follow, from the latter state- 
 ment, that the influence of a central reservoir of molten 
 matter would scarcely be felt at the surface. If this 
 be correct, how can we account for the fact of earth- 
 quakes, or explain the breakages and innumerable 
 rents which were produced in ancient epochs ; the 
 fracturing of solid rocks ; the uptilting of beds, and 
 sometimes their complete overthrow ; the increase of 
 temperature in deep mines, and the identity of volcanic 
 productions in all countries, as well as the existence of 
 thermal springs'? 
 
 But there is a difference between saying that we 
 
 * May not the force thus liberated be pressed into the service of 
 nature on the exterior of the earth, and, in its various modifica- 
 tions, as heat, electricity, motion, &c., be necessary to the well- 
 being of organic forms ? This view would thus connect any 
 plutonic disturbance with the vital forces, and few will deny there 
 is some conneci^on between them. 
 
16 POPULAR GEOLOGY. 
 
 cannot yet tell which were the primitive rocks, and 
 averring, as some geologists do, that " the earth shows 
 no traces of a beginning." The student who finds as 
 he descends in the scale of rock-succession, that the 
 life-forms become less highly organized, and more re- 
 moved in their typical characters from present species, 
 knows as surely that he is reverting to the origin of 
 life, as that he will reach the apex of a triangle when 
 he traverses its inclining sides from the base. Now 
 although we cannot state definitely that the Laurentian 
 formation bounds the appearance of organic forms, 
 still we know that this is almost the zero of fossil 
 remains. The slates and flagstones of the Cambrian 
 rocks are quite as likely, or more so, to preserve the 
 remains of the creatures which lived in the waters 
 whilst they were being deposited, as the rocks of 
 other formations. Nay, whilst we find that the me- 
 chanical laws of nature, in the rain-drops which pit 
 the sandstones, and the ripple-marks which wrinkle 
 the shales, were the same as they are at present, every 
 other marking which cannot be^referred to these agen- 
 cies, and which may have had a vital origin, is very 
 obscure. What then is the plain inference of these 
 facts '? We cannot say that these rocks have not been 
 explored so well as the rest, for they have been perhaps 
 still more carefully investigated. Neither can anyone 
 be charged with attempting to conceal a fact that might 
 militate against a favourite theory for the least traces 
 of anything organic which has come from these 
 " bottom rocks" has been hailed by every geological 
 
POPULAR GEOLOGY. I/ 
 
 student with interest and pleasure. Without com- 
 mitting myself to the statement that the Laurentian 
 contain the first traces of life, and that before their 
 deposition the world was "a waste, howling wilder- 
 ness," habited only by the whirlwind and the storm 
 I do assert that the fullest information known upon 
 this subject will bear us out in looking upon them as 
 the earliest stages in our planet's history. 
 
 But there is a school of geologists who look upon 
 the present system, from the lowest Cambrian to the 
 latest Tertiary, as being only one out of an endless 
 succession ; and who regard the entire crust of the 
 globe as passing through a series of changes,. beginning 
 with the igneous rocks, which are afterwards decom- 
 posed and deposited as stratified ones, to be metamor- 
 phosed by heat as they sink within the influence of 
 the earth's internal reservoir, until they return to a 
 fused and igneous state, to be again solidified and to 
 pass through the sedimentary state, returning as before 
 to the molten condition. It would seem, therefore, 
 from this hypothesis 1 , that we may consider the solid 
 crust of our planet as encircling a mass of incandescent 
 matter, and that, during the slow and gradual sub- 
 mergence of wide areas of the surface, the lower rocks, 
 to whatever formation they may belong, become changed 
 by the intense heat to which they are thus subjected, 
 and finally become melted as they come in contact 
 with the fluid matter; just as a mass of lead 
 thrown into a crucible half filled with the molten 
 metal, is first melted around the surfaces of contact, 
 
18 POPULAR GEOLOGY. 
 
 The new additions thus received by the internal 
 reservoir are counterbalanced by the numerous ejec- 
 tions from volcanic mouths and through basaltic 
 dykes. This theory, however, is not so tenable as 
 when Hutton first propounded it. Thus, the meta- 
 morphic rocks, as they were called, such as mica- 
 schist and gneiss, are not always found to be the 
 lowest seated ; and it does not follow, that these rocks 
 are just passing into the original fluid state, because 
 they differ in some respects from the rest. Some of 
 the stratified beds of the upper ~New Eed Sandstone are 
 nearly as micaceous in their character as these meta- 
 morphic rocks; and between the gneissose bands in the 
 lower Silurians of Scotland, there are beds containing 
 fossil remains. How happens it, therefore, that the 
 whole of the intervening beds have not been metamor- 
 phosed in a similar manner ? However conflicting the 
 theories concerning the origin of the earth and the 
 first traces of its early life may be, I do not doubt that 
 geology will, ere long, be in a sufficiently secure posi- 
 tion to indicate when those epochs commenced. 
 
 The second class of igneous rocks are termed 
 " volcanic," because of their closer affinity and resem- 
 blance to them than to those of the granite family. 
 They are peculiar also, from having all been formed at 
 or near the surface, instead of having been subjected 
 to great pressures of overlying rocks, as in the case of 
 the granites. Among the "volcanic" class which 
 were erupted during geological times, trap, or basalt, 
 and greenstone were the commonest. The principal 
 
POPULAR GEOLOGY. 19 
 
 difference between basalt and the productions of 
 modern volcanoes is the greater degree of compactness 
 which the former possesses, and in the prevalence of 
 augite instead of hornblende in the lavas. The variety 
 of simple minerals contained in lava is very great; 
 upwards of a hundred have been discovered in the 
 neighbourhood of Vesuvius alone. Two minerals, how- 
 ever, are generally in sufficient abundance as to be 
 deemed constituents of this rock, viz., felspar and 
 augite. Quartz and mica, so abundant in the granite 
 rocks, are comparatively rare in lava. Obsidian is a 
 vitreous lava which has been formed by rapid cooling ; 
 it has a black colour when in the mass, but is trans- 
 lucent along its edges when in thin fragments, and is 
 also one of the heaviest varieties of this rock. On 
 the other hand, pumice stone is a spongy lava, gene- 
 rally of a light colour, and has been produced by the 
 access of air or gas to the molten matter, and is there- 
 fore the scum or froth of the more solid lava-stream. 
 Transition from obsidian to pumice has been met with 
 in varieties of lava. 
 
 Pitchstone is a glossy, felspathic rock, and has a 
 great resemblance to pitch ; it often occurs in inter- 
 posed beds and dykes, and is found graduating into 
 obsidian, which is a decidedly volcanic rock. The 
 transition of basalt into pitchstone, observed by Dr. 
 Macculloch in Scotland, and elsewhere, connects the 
 ancient basalt with the lava of modern volcanoes. This 
 mineral is very abundant in the Isle of Arran, and the 
 Scuir of Eigg. 
 
POPULAR GEOLOGY. 
 
 But the most common rocks of this class, met with 
 in the olden formations, are basalt, or trap, and green- 
 stone. In southern India there jis a vast tract of 
 country, many thousands of square miles in extent, 
 where the strata have been broken up and penetrated 
 by immense outbursts of these rocks. Sheets of trap, 
 which were evolved from the igneous crucible below, 
 when the country existed as the bottom of a widely- 
 extended sea flowed far and wide over its uneven 
 area, The sandstones of India are said to be always 
 the richest in diamonds in the neighbourhood of these 
 igneous rocks. Basalt is rather a vague term ; any 
 dark coloured rock has been called by it, such as 
 clinkstone, compact felspar, and greenstone ; or else it 
 has come under the still more vague definition of 
 " trap." The latter name is derived from the miners 
 of Sweden, in the language of which county trappa 
 signifies a step or stair, and was applied to this rock 
 on account of its occurring in large tabular masses 
 rising above each other like a flight of stairs. Basalt 
 often occurs in the columnar form, like the worked 
 sides of hexagonal pillars, but this structure is now 
 abandoned as a distinctive character of this rock. In 
 this state it occurs, as is well known, at Fingal's cave, 
 in Staffa ; and at the giants' causeway, at Fairhead, 
 Ireland. From divers experiments it would seem that 
 this peculiar form is due to the pressure against each 
 other of numerous spheroids or globules of the fused 
 matter during its cooling. The basalt of the giants' 
 causeway may be seen capping all the low chalk pro- 
 
POPULAR GEOLOGY. 21 
 
 montories along the coast, and is quite amorphous, or 
 uncrystallized in its character. Sometimes the hex- 
 agonal pillars are found in a hended condition, which 
 lias occurred from vertical pressure acting upon them 
 after they had been formed, but before the matter had 
 quite lost its elasticity from heat. As the felspar of 
 basalt increases in quantity, and its hornblende or 
 augite becomes coarser-grained it passes into green- 
 stone. Some varieties of this latter rock contain small 
 hollows, which were left by the escape of the gas when 
 the rock was in a semi-fluid state : these cavities are 
 often filled with crystals of carbonate of lime, quartz, 
 agates, and other minerals. But it is in the state of 
 dykes that these rocks most abound. Now during the 
 consolidation, or hardening, of strata they often shrink 
 and contract, causing crevices and rents to occur. 
 Thus, granite will contract and reduce its previous 
 volume more than ten per cent. These cracks and 
 fissures are afterwards filled up with basaltic matter or 
 greenstone in a fused state, and are then termed 
 " dykes." * Some of thsm are of very great extent. 
 The great Cleveland dyke, which runs through the 
 counties of Durham and York, can be traced for 
 seventy miles. These dykes are generally more crystal- 
 line in the middle than at the sides, owing to the 
 molten matter having had its heat conducted away by 
 
 * It will be evident that these dykes may be of different geolo 
 gical ages. No attempt has as yet been made to collate the dykes 
 of the same age in different parts. Such a comparison inigat 
 result in establishing common data. 
 
22 POPULAR GEOLOGY. 
 
 the solid rocks with which it came in contact. Most 
 of the strata traversed by these dykes are altered by 
 the heat to which they have been subjected during 
 their formation. In the Isle of Anglesey the limestone 
 is altered to a distance of thirty feet, becoming quite 
 crystalline, and losing all traces of its organic remains. 
 The mountain limestone of the Peak, in Derbyshire, 
 which is traversed by numerous layers and intrusions 
 of greenstone and trap, is often converted, in their 
 neighbourhood, into a saccharoid marble. In some 
 parts of Ireland, in the county of Antrim, for instance, 
 trap-dykes penetrate through the chalk and convert it 
 into crystalline marble for a distance of eight feet on 
 either side. When these dykes traverse coal-strata, as 
 is often the case, the shales which overlie the coal are 
 often baked like porcelain, and the coal is converted 
 into soot and coke. Such a phenomenon occurs in the 
 North of England, at Cockfield fell, where the coal is 
 baked into coke for a distance of ninety feet from the 
 trap. In the Isle of Skye the neighbouring sandstones 
 are changed into almost pure quartz ; and at Bartes- 
 tree, Lugwardine, a dyke of greenstone is seen to tra- 
 verse and alter the lower Old Eed sandstone, and has 
 literally roasted the beds into hornstone. 
 
 The age of some of these dykes can be told from 
 noticing their position. Thus, suppose two layers of 
 rock lie unconformably to each other, and that a dyke 
 of trap-rock is seen traversing the lower rock, but 
 terminating with it when it comes in contact with the 
 lower surface of the upper, would it not be a proof 
 
POPULAR GEOLOGY. 23 
 
 that the lower rock had first been consolidated and had 
 shrunk, allowing an injection of fused trap to fill up 
 the fissure, before the upper beds were formed, for 
 the dyke does not pass upwards into them? These 
 dykes are not peculiar to the older formations ; neither 
 have we to suppose that other forces then existed to 
 produce them, than those which are now extant. Sir 
 Charles Lyell observes that " we are entitled to expect 
 that if we could gain access to the existing bed of the 
 ocean, and explore the igneous rocks which have been 
 poured out within the last six thousand years, beneath 
 the pressure of a sea of an immense depth, we should 
 behold formations of modern date very similar to the 
 most ancient trap-rocks of our island." Even within 
 modern times, irregular shaped and narrow wedges of 
 volcanic matter have crossed through the beds of ashes, 
 scoriae, sand, and lava, which envelope and form the 
 sides of Mount Vesuvius. 
 
 Greenstone includes a great number of igneous rocks, 
 and consists of a mixture of felspar and hornblende- 
 Its colour is generally of a dull green, both light and 
 dark, although it is occasionally found nearly black. 
 These beds were nearly all of them poured out along the 
 bottoms of ancient seas, as sub-marine lava streams, 
 and consequently we find that where they occur as 
 layers their lower surface is moulded to the irregularities 
 of the old sea bottom. The greenstones which so 
 frequently occur in the mountain limestone are of a 
 dark green colour, with white and black crystals of 
 augite imbedded in them the crystals having filled up 
 
24 POPULAR GEOLOGY. 
 
 the cavities which once existed in the mass. Some of 
 the greenstones of the coal measures are quite vesicular, 
 or porous, and resemble the lavas of modern volcanos 
 so much that the uneducated eye can perceive their 
 affinity. In Derbyshire this variety goes by the local 
 name of " loadstone." Vast sheets of this mineral 
 when in a fluid state flowed over the mountain lime- 
 stone sea, for there are several bands intercalated with 
 the strata. So far back as the Silurian age molten 
 greenstones flowed for many square miles over 
 the sea bottoms in South Wales ; and in South 
 Staffordshire they have been found extending over an 
 area of twenty square miles, having a thickness varying 
 from fifteen to twenty feet. 
 
 The outburst and eruptions of igneous rocks have 
 had much to do with the formation of mineral veins. 
 It would be somewhat curious to show how such out- 
 bursts, which took place in some bygone geological 
 epoch, have influenced the inhabitants of many parts 
 of the earth, by the discovery of some precious metal 
 to which these disruptions gave birth. How the 
 metals were originally distributed when our planet 
 came fresh from the hands of its Creator, we cannot 
 say. Some geologists have supposed the whole of 
 the sixty odd elementary bodies, which together form 
 the earth's crust, to have been originally all mixed up 
 in the molten mass which occupies the interior of the 
 earth. If such were the case, and it is not unreason- 
 able to suppose so, we might expect to find metals, 
 according to their abundance in nature, more or less 
 
POPULAR GEOLOGY. 25 
 
 mixed up with every igneous rock. And, further, as 
 many of the sedimentary rocks have been formed from 
 the denudation and waste of the igneous ones, the 
 minerals or metals would then be transferred to these 
 second deposits, and loe distributed through their 
 mass. For instance, there is scarcely a bed of any 
 rock which does not contain more or less of iron, either 
 as an oxide or as a carbonate ; and some of the sand- 
 stone rocks are green with the ores of copper, mixed 
 mechanically with the sand, as in the case of iron. It 
 may be, and probably is the case, that more or less of 
 metallic matter is mixed up with almost every stratum 
 of rock. Certainly, from the chemical affinities of 
 these bodies, we may easily conceive that some rocks 
 will be richer in one metal than another, and that 
 there may be many cases in which some of them are 
 altogether excluded ; but I wish to show that the 
 dispersion of these substances is not difficult to be 
 accounted for, and that they only need careful investi- 
 gation to be found. Arsenic, for instance, has b.een 
 shown by Dugald Campbell to be an almost invariable 
 constituent of the sandy beds of streams and rivers. 
 Silver, also, is more generally diffused than is commonly 
 conceived ; it is found in sea-salt, in rock-salt, in many 
 varieties of sea- weed, and even in coal ; and it is calcu- 
 lated that every cubic mile of sea- water contains upwards 
 of fifteen tons of this valuable metal I Copper, lead, man- 
 ganese and other metals are more or less diffused 
 through sea-water in a similar manner, as every careful 
 analysis will show. Gold occurs mixed with lead, 
 
26 POPULAR GEOLOGY. 
 
 silver, copper, pyrites, &c., and has recently been 
 discovered to be even a common ingredient in clay ! 
 Mr. Eckfeldt, of the Philadelphia mint, has made some 
 interesting investigations, tending to show the general 
 distribution of this precious metal. From beneath the 
 new market-house of that city, some of the clay upon 
 which it stands was dug out, taken from a depth of 
 fourteen feet. Careful analysis and investigation 
 showed that it contained one part of gold in one and a 
 quarter million parts of clay. The deposit from which 
 the tested material was obtained, covers an area of 
 about ten square miles ; the average depth being about 
 fifteen feet. Gold was then sought for in various other 
 places, among the rest in a brick-field in the neigh- 
 bourhood, and always with the same success. Accord- 
 ing to the assay every cubic foot of this clay contains 
 gold to the value of three halfpence, and the contents 
 of this deposit being ascertained to be four thousand, 
 one hundred and eighty millions of cubic feet it 
 follows that it contains gold to the value of twenty- 
 five millions of pounds sterling ! In fact, there is 
 enough of gold in every brick to gild its surface two 
 square inches. It is possible, as a writer in the London 
 Review observed, if the London clay of the Tertiary 
 formation be equally rich in this metal, that there is 
 underlying the metropolis more gold than would equal 
 in value its almost fabulous wealth ! Now clay and 
 sand are natural deposits, and do not differ from rocks 
 in their composition ; the only difference being that 
 the former have not been consolidated. Were we to 
 
POPULAR GEOLOGY, 27 
 
 suppose the clay deposits, just mentioned, to be con- 
 verted into solid rocks, and afterwards rent by faults 
 and fissures, chemical and electric agencies would in 
 time cause the minute particles of metals to aggregate in 
 the fissures, lining each side until the rents were filled 
 up, and thus forming what would be, in truth, a 
 metallic vein. That this is the way in which many 
 metal veins have been formed, is evident from the ap- 
 pearances which they present. Thus, Sir Henry de la 
 Beche noticed several veins in Cornwall where the 
 deposits of metal had lined the walls of the fissures at 
 successive times ; and this phenomenon is more par- 
 ticularly common in the lead mines of Derbyshire. 
 These metals, however, are seldom found thus in a 
 pure state, only about one or two out of the whole list 
 occurring so ; and each metal has certain combina- 
 tions in which it most often occurs. Thus, lead is 
 chiefly found combined as a sulphide ; copper, either 
 as an oxide, carbonate, or sulphide, iron either as an 
 oxide or carbonate \ and so with all the rest. As they 
 occur in veins they are often enclosed in a matrix 
 of spar, which is either of carbonate of lime or of 
 quartz ; and in the case of lead very often of barytes. 
 Xow this sparry matter is most commonly found 
 assuming the crystalline form belonging to it, and 
 shows, therefore, that the particles must have been free 
 to arrange themselves in obedience to their chemical 
 laws. It is not unfrequently the case that we may 
 observe in a vein, where the walls were once coated 
 with these crystals, how the next additions of mineral 
 
28 POPULAR GEOLOGY. 
 
 matter covered them up, and assumed in their outer 
 surface, in turn, the crystalline forms affected hy the 
 latter. This is another proof of the^ chemical origin of 
 some of the mineral veins. Some of these sparry 
 minerals, as for instance, quartz, must have been dis- 
 solved in hot water, for cold water will scarcely hold 
 any of it in solution ; and it is singularly in support 
 of this supposition that the veins which have the richest 
 matrices of this mineral are situated in the lowest rocks, 
 and consequently those ivhich have been most subjected 
 to the heat of the interior of the earth. Now, as a 
 general rule, such mineral veins are most numerous and 
 most productive in the neighbourhood of igneous rocks, 
 such as granite, greenstone^ and basalt ; and especially 
 where such rocks and the sedimentary ones meet 
 thus showing that the heat which has affected the 
 latter has done much towards the segregation of their 
 metallic matter. 
 
 Many mineral veins, doubtless, have been formed by 
 sublimation from the intense heat of the earth's in- 
 terior ; and the metals have lined the walls of the 
 fissures which communicate with it. Of this class of 
 mineral depositions, that of silver, which is often found 
 in strings or bunches, is an example. Other metals, 
 such as gold and platinum, may have been the effect of 
 chemical precipitations ; and it is not improbable to 
 suppose that the earth's crust has sometimes acted like 
 a huge electric battery the various rents, moistened 
 with heated water diluted with acids, serving to occa- 
 sion shocks which would segregate the metallic particles 
 
POPULAR GEOLOGY. 29 
 
 diffused through the mass, along their walls. Con- 
 cerning those veins which have been formed by sub- 
 limation, we have instances in the effects of recent 
 volcanoes ; among whose products no fewer than five 
 metals have been found, viz., copper, iron, arsenic, 
 lead, and selenium, and the vapours which rise from 
 fumarolles are known to cause the sublimation of 
 chlorides of iron, copper, and lead, which fill the 
 fissures on the margin of the strata. Iron glance is 
 also formed by sublimation of the vapours on the walls 
 of the fissures of open veins on the margin of volcanic 
 craters ; and is also found in the fresh lava-currents of 
 the volcanoes of Stromboli, Vesuvius, and Etna. 
 
 From a knowledge of the phenomena observed 
 during volcanic eruptions* and especially when these 
 take place in or near to the sea we may identify simi- 
 lar productions which originated whole milleniums 
 ago. There is often ejected from volcanoes, as I before 
 observed, ashes and scoria, which are carried to a great 
 distance by the winds. Should this take place in the 
 sea the sanie matter would be strewn along its bottom, 
 as was the case when Hotham island first appeared, and 
 more lately still, during the recent eruption of Vesuvius, 
 when the waters of the neighbouring sea lay thickly 
 covered with cinders, and were turbid with mud, or, as 
 was the case with Santorino, and Nea Kaimene, only the 
 other day. Now it is often the case that poisonous gases 
 are emitted during these eruptions, carrying death and 
 destruction to the inhabitants of the waters, so that 
 the muddy sediments which originated from such a 
 
30 POPULAR GEOLOGY. 
 
 source would enclose shells and other marine creatures, 
 exactly in the same way as ordinary deposits. These 
 deposits are termed " volcanic tuffs," and have taken 
 place, perhaps, during every geological period ; whilst 
 their age can be told in the same way as that of other 
 beds, viz., by the organic remains which they enclose. 
 Such volcanic tuffs are found in Devon and Cornwall 
 containing trilobites and corals ; and it is probable, as 
 Hugh Miller observes, that the gases from submarine 
 volcanoes caused the death of the mail-clad fishes of 
 the Old Eed Sandstone, which are seen stretched out 
 in a defensive attitude as though they had died a 
 sudden death. This was, also, probably the cause of 
 the death of so many of the cuttle-fish of the Lias 
 for in like manner Dr. Buckland observes, that they 
 died suddenly, and had a rapid interment, for their 
 ink-bags are found unexpended, which would not have 
 been the case had they not been overtaken very sud- 
 denly. In the carboniferous limestone of the Isle of 
 Man, these volcanic tuffs occur in several bands, and 
 enclose the shells and zoophytes which are peculiar to 
 that formation. "What monuments do the rocks enclose 
 of former catastrophes of the antagonistic action of 
 fire and water, and of the sacrifice of life which then 
 as now was the result ! In ancient times, when no 
 human eyes were present to observe and catalogue 
 the phenomena outbursts of igneous matter from the 
 internal reservoir of the earth fractured and broke up 
 the solid crust, and the quiet sea was tempest-tossed 
 with the upheaval of new lands, around whose shores 
 
POPULAR GEOLOGY. 31 
 
 the turbid waters hissed and seethed, filling the atmos- 
 phere with steam, and darkening for leagues around the 
 light of heaven ! Upon the raging sea, shoals of dead 
 fishes floated away and the bottom of the deep was 
 turned into a sudden sepulchre for myriads of its 
 quiet inhabitants ! What though no human observer 
 beheld all this, the " everlasting hills " do not the less 
 surely catalogue the details even far more truthfully 
 than any human record could have done ! 
 
 But, although the igneous rocks which we have 
 noticed, originated either beneath the pressure of vast 
 rock-masses, or beneath that of deep seas we are not 
 to suppose that, in the bygone geological periods, the 
 dry land was more free from convulsions than it now 
 is. Doubtless many a time the landscape was obscured 
 by volcanic smoke, and desolation was often carried for 
 miles around their foci. Ever since the first dry land 
 appeared above the waters such phenomena have taken 
 place ; although the records of the earliest of these 
 disturbances are necessarily obscure, as upon the 
 sinking of these areas the materials would be the first 
 to be removed by the agency of the waves and currents. 
 It is only in Tertiary times that we can point out 
 such phenomena. Thus in Auvergne, in central 
 France, there is a chain of extinct volcanoes, which, 
 long before the historic period began, had ceased to 
 belch out their fiery matter. And yet the streams of 
 lava which flowed from them when in action, can be 
 " traced distinctly descending from many of the craters, 
 and following the lowest level of the existing valleys." 
 
POPULAR GEOLOGY. 
 
 Their age is known from the tuffs, which are found 
 enclosing Eocene fossils; and the cones, of which 
 there are several hundreds, must have been in full 
 activity during the many thousands of years which 
 have elapsed since succeeding formations took place. 
 Similar extinct volcanoes, which have been in action 
 since the formation of the Boulder clay are visible in 
 some parts of Australia, as well as in several other 
 parts of the globe. All these phenomena teach us to 
 recognize in the government of past geological ages the 
 Being who is "the same, to-day, yesterday, and for ever." 
 We might show how many of -these eruptions, rich 
 as they were in phosphates, served as a storehouse from 
 which many of the extinct and existing animals have 
 drawn their bony and shelly skeletons ; and, also, how 
 the sheets of molten rock have roofed in the precious 
 vegetation of the coal formation thus preserving it 
 from the denuding action of subsequent seas, and con- 
 serving it until the age of man. We have already 
 seen how all the rocks have, more or less, been pro- 
 ductive of the metals which now form such a necessity 
 in the advancement of human civilization so that the 
 metallic particles which would otherwise have been 
 uselessly scattered through the various deposits, as in 
 the case of the Philadelphia clays, through the forces 
 of which I have been speaking, igneous and their 
 resulting chemical agencies, have, been carefully segre- 
 gated into veins and lodes, awaiting nothing, to turn 
 them to account, but the mind-directed labour of man 
 a being intended in the advancement of his own 
 happiness and comfort, to be a " co-worker with God.' 
 
33 
 
 LECTUEE II. 
 
 INFLUENCE OF PHYSICAL GEOGEAPHY 
 ON GEOLOGICAL PHENOMENA. 
 
 DR. MANTELL, in the preface to his " Medals of Crea- 
 tion," makes the remark that " there can be no geology 
 for beginners," that we must, necessarily, know some- 
 thing of the earth as it is, before we can arrive at any 
 definite conclusions concerning the earth as it was. 
 Geologists are finding out the truth of this assertion 
 more and more every day. To most people who are 
 unacquainted with geological phenomena, the manner 
 with which geologists talk of the denudation of rock- 
 masses, of the uplifting of dry lands, of the formation 
 of beds along the old sea-bottoms, and of the extinction 
 and creation of numerous species of animals and 
 plants seems not only strange, but actually to border 
 upon the ridiculous. They cannot understand how he 
 can speak so grandiloquently, and so they set down 
 many of his deductions as sheer enthusiasm. Now 
 this, in a great measure, arises from their being ignorant 
 
 D 
 
34 POPULAR GEOLOGY. 
 
 of the natural processes which are going on in various 
 parts of the globe at the present day. The study of 
 physical geography, the science which treats upon these 
 various changes, has grown in a great measure with 
 the advancement of geological science. More than any 
 class of men, perhaps, the geologist is obliged to be an 
 observer, and thus a habit of noticing all physical 
 changes is acquired, which, together with the tact with 
 which he applies his information to the elucidation of 
 geological phenomena has done much to distinguish 
 him among savans. Now it only needs that some of 
 these numerous phenomena should be made known, for 
 us to perceive that time alone is required to produce the 
 most important changes, and I intend, in the course 
 of the present lecture, to lay a few of them before you. 
 
 Most of you, doubtless, are aware of the effects of 
 common rain-floods. You have seen the rolling waters, 
 thickly turbid, hastening down the stream to the 
 rivers and the sea, \.here to deposit their burden of 
 mud, the waste of the lands through which they have 
 passed. These phenomena, however, may have only 
 drawn your attention now and then, but there are 
 others which often pass unnoticed, and yet which pro- 
 duced the most important results. It is somewhat 
 singular that those very agencies, which, owing to their 
 apparent insignificance, we are apt to overlook, are, in 
 the issue, of the greatest importance. Who would 
 think, on a hot summer's day, that the heat is causing 
 the decomposition, or rotting, of the softer rocks ? And 
 yet this is the case, for the moisture which these rocks 
 
POPULAR GEOLOGY. 35 
 
 absorbed in damp weather is evaporated on these sultry 
 days, and in this manner the rock is slowly wasted 
 away. In frosty seasons moisture produces the same 
 effects, but acts through other causes ; for the water, 
 instead of being evaporated, is now expanded by the 
 frost, and thus the particles of the mass are separated, 
 and the rock rots away. Now you will perceive that 
 the action of these various agents will be more or less 
 effectual according to the hardness of the stone. Nay, 
 to understand something of the " wear and tear " to 
 which our old earth is daily subjected by natural 
 phenomena we must take into account the evaporation 
 which is continually going over every sheet of water. 
 Thus, the north-east trade winds, which sweep over the 
 Atlantic, cause a yearly evaporation of fifteen feet of 
 water over an area of at least three millions of square 
 miles. At Calcutta, and on the Red sea the annual 
 evaporation is the same. It is calculated that the 
 force which would be required to lift the usual vapours 
 from the surface of the earth, is eight hundred times 
 greater than all the water power of Europe. "We see, 
 therefore, what a vast body of water is suspended in 
 the clouds, and employed for watering and fertilizing 
 the earth. Sometimes this moisture is condensed on 
 high mountain-tops, where it forms the region of 
 eternal snow. The lower limits of this snow-line form 
 glaciers, which are continually travelling, melting, 
 pounding, and crushing the rocks into mud as they 
 move, and disengaging great masses of stone, which 
 they carry down into the valleys. Or, the vapours 
 
 D2 
 
36 POPULAK GEOLOGY. 
 
 may be distilled upon the low lands as dews and rains, 
 which form rills, streams, and rivers. Here we see a 
 body of water which, of course, was quite pure when 
 evaporated, returning to its source, the ocean, laden 
 with the spoils of the beds over which it has flowed, 
 and of the countries which it has drained. And it is 
 estimated that the mean depth of rainfall which 
 descends over the entire surface of the earth is sixty 
 inches every year. Now we have only to remember 
 that this circulation does not merely take place once or 
 twice, but thousands of times, and we shall cease to 
 wonder that so much material is carried down to the 
 sea, and deposited along its bottom. Let us take one 
 or two examples of the amount of matter which some 
 of the larger rivers are known to carry down. Mud, 
 from such rivers as the Amazon, the Orinoco, and the 
 Mississippi, is found discolouring the ocean hundreds of 
 miles out of sight of land. Of course the proportion 
 thus borne down depends very materially upon the 
 force of the stream ; and Mr. Hopkins has shown that 
 the power of water to move bodies increases as the 
 sixth power of the velocity of the current. The 
 quantity of mud carried down by the Ganges, is esti- 
 mated at 368,077,440 cubic feet per annum. Part of 
 this is deposited at the river's mouth, where it forms a 
 gentle inclined plane, a hundred miles in length, and 
 sloping from four fathoms to sixty in depth. We 
 shall obtain a better idea of this mass, if, as Sir Charles 
 Lyell states, we take into consideration that it is 
 equivalent to a fleet of two thousand Indiamen, each of 
 
POPULAR GEOLOGY. 37 
 
 two thousand tons burden, carrying down and dis- 
 charging their cargoes into the sea. Mr. Jukes 
 estimates that the material would cover a square space 
 of fifteen miles on each side, a foot in depth every 
 year, or would raise the whole surface of Ireland one 
 foot in the space of a hundred and forty-four years ! 
 The Burampoota, another Indian river, is computed to 
 carry down about a similar quantity. In America, 
 where the Mississippi empties itself into the sea through 
 its many mouths, there is an area of deposit thirteen 
 thousand square miles in extent, averaging a uniform 
 thickness of five hundred and twenty-seven feet. 
 Now this has been formed solely by the vast quantities 
 of matter which the river has brought down ; and, at 
 the present time, the annual deposit is calculated at 
 3,702,758,400 cubic feet ! By a simple arithmetical 
 calculation it will be seen that at this rate of deposition, 
 it must have taken the Mississippi sixty-seven thousand 
 years to have formed this delta. Taking into con- 
 sideration the quantity of alluvial matter in the plains, 
 Lyell assigns about a hundred thousand years to its 
 formation. Bischoff has further calculated that the 
 carbonate of lime which is carried down by the Rhine 
 each year, is sufficient to form three hundred and 
 thirty-two thousand millions of oyster-shells, each of 
 the usual size ! 
 
 But, whilst the rivers of the earth, in all ages of its 
 history, have been thus altering the surface, the sea has 
 been the great laboratory in which the mightiest effects 
 have been produced. The manner in which all the 
 
38 POPULAR GEOLOGY. 
 
 river-sediments have been earned down into it, and 
 re-formed into solid rock, and then upraised into new 
 continents, reminds us of some of the mythological 
 stories of Greece or of the transmutation-processes in 
 which the old alchemists indulged. "The many- 
 sounding sea " has been the subject of poets from the 
 time of Homer to that of Byron ; and much that is 
 grand and beautiful has been said about it. But there 
 is more true poetry in looking upon the sea as the 
 mother of new lands, and of lands which have since 
 given origin to all- the legends of romance than in all 
 the sentiment which ever dribbled from human lips. 
 The sea is the most powerful agent emploj^d by 
 nature in effecting her changes, and has been chosen by 
 its Creator for the most sublime of purposes. It is the 
 mortar in which have been pounded above fifteen miles 
 of stratified rocks. From time to time, in its deeper 
 waters, limestones have been elaborated, and vast beds 
 of conglomerate, the broken-up fragments of its ancient 
 shores, have been deposited. In its estuaries and 
 lagoons Nature's coal-cellars have been stored ; and it 
 has been through the slow growth of hundreds of cen- 
 turies that these masses have been hardened into rock 1 
 The sea has never been still. Ever since God 
 divided the waters from the land, its currents have 
 gone forth and influenced climates, which were long 
 since removed. Its tidal waves have laved the shores 
 of continents, which, since then, have become its prey, 
 and whose ancient life is now locked up in the rocks 
 the only relics of those extinct lands ! 
 
POPULAR GEOLOGY. 39 
 
 Living upon the solid land, our recollection seems to 
 have established it as existing for ever, and we associate 
 all that is enduring with its rocky foundations. On 
 the other hand, the sea has ever been to us an emblem 
 of fickleness and change. But geology gives the lie to 
 the secure conviction of centuries ; nay, did we but 
 live in countries where the earth is rocked by earth- 
 quakes and desolated by volcanoes we should speedily 
 change our cherished opinions. 
 
 It is the sea, then, of all created things, which has 
 been the most enduring ! 
 
 " Time writes no wrinkle on thine azure brow, 
 Such as creation's dawn beheld, thou rollest now." 
 
 Old lands, like foundering ships, have slowly settled 
 down, and sea-monsters have lived and browsed upon 
 the green meadows of sea-weed which have grown over 
 their surfaces. Ocean-bottoms have been uplifted and 
 consolidated into rocks but the sea, true to the first 
 principles of natural philosophy, has from time to 
 time, drawn off its waters to the lowest level, again to 
 commence their work of denudation and deposition ! 
 
 It is owing to its numerous currents that the ocean 
 becomes such an important agent in Nature's changes. 
 Thus, the whole volume of the Gulf-stream moves along 
 the North American coasts, at the rate of eighty miles 
 a-day. Now, what rock-bound coast, however hard the 
 material, can withstand the attacks of so vigorous and 
 so constant an enemy 1 In Hampshire, the farmers 
 commonly reckon the losses of their land, from the 
 encroachments of the sea, at a yard for every year. 
 
40 POPULAR GEOLOGY. 
 
 Along the whole of the southern coasts this gradual 
 denudation is going on ; the peninsulas of Purbeck 
 and Portland are wasting away, owing to the soft 
 Kimmeridge clay, which underlies the limestone, being 
 abraded by the waves, and so causing the overlaying 
 beds to tumble down in masses. Since Shakespere 
 wrote that celebrated notice of Dover cliffs, in "King 
 Lear," which almost turns one's head dizzy on reading 
 it they have suffered many and repeated losses. 
 Massive fragments have fallen down, owing to the 
 undermining of the base by the sea; some of these 
 falling masses have shaken the town like an earth- 
 quake, and caused great alarm among the inhabitants. 
 In this manner the height of the cliffs is considerably 
 lessened, and the slope of the hill, instead of being so 
 overhanging that 
 
 " The crows and choughs, that wing the midway air, 
 Seem scarce so gross as beetles," 
 
 is now sloping towards the land. The Goodwin sands, 
 upon which many a fair vessel has met its fate, are 
 not merely an accumulation of marine driftings, but 
 the spoil which the sea has won from the solid land. 
 History assigns them their name, owing to their having 
 once formed part of the estate of Earl Goodwin, of 
 Saxon renown. And it has been found by boring into 
 them, that, after fifteen feet of sand have been passed 
 through, there is a bed of blue clay which rests upon 
 the solid chalk. Nay, from the Shetland isles, off the 
 coast of Scotland, to the Land's-end, in Cornwall, 
 physical changes, more or less, are affecting the whole 
 
POPULAR GEOLOGY. 41 
 
 British coast. The Shetland isles, although composed 
 of one of the hardest rocks, are slowly wasting away 
 before the violence of the Atlantic currents ! And the 
 whole of the Yorkshire coast, from the mouth of the 
 Tees to the Humber, is being abraded by similar 
 attacks. The present configuration of this coast-line, 
 with its bays and havens has depended upon the 
 h irdness of the various rocks which have been exposed 
 to these denuding agencies. Some towns, of ancient 
 prosperity, such as Hartburn, Hyde, and Ravenspur, 
 are remembered only in history, for they have long 
 since become the prey of the waves ! The extensive 
 chalk-cliffs, especially, are suffering from these attacks, 
 and the rapidity with which they are worn away may 
 be gathered from the following fact. At Sherringham, 
 in Norfolk, in 1805, an inn was built some fifty yards 
 from the sea; but in 1829, seventeen yards of this 
 distance had been swept away, and only a small garden 
 was then left between the house and the sea !* 
 
 * The Rev. John Gunn, F.G.S., mentioned at a recent meeting 
 of the Norwich Geological Society that he had known houses to 
 stand in one part of Norfolk where there is now sea-water deep 
 enough for large ships to float in, and that vessels are actually 
 passing and re-passing over the very sites of these cottages ! The 
 waste of the Norfolk coasts is such a well known fact to Norfolk 
 people, that it needs but a single illustration to remind them of the 
 extent to which it is being carried on. The bottom of the German 
 ocean, according to the Admiralty chart, is strewn with the debris 
 thus obtained, in the most heterogeneous fashion. The same 
 causes have rendered the coasts of Norfolk as dangerous as any in 
 the world, from the numerous sand banks which occur. A reference 
 to the wreck chart will show the abundance of these banks. 
 
42 POPULAR GEOLOGY. 
 
 Of any country, perhaps Holland and the neigh- 
 bouring islands have suffered most from the en- 
 croachments of the sea. Floods have swept over it 
 and destroyed as many as seventy three villages at a 
 time ! Not only so, but in some cases the waters have 
 maintained their newly acquired position, and have 
 since existed as estuaries and lakes. Such is the 
 Zuyder-Zee, or South sea ; so called to distinguish it 
 from the North sea. The Zuyder-Zee covers an area 
 of 12,000 square miles, and was not in existence in the 
 time of the Romans. At that time an extensive marsh 
 occupied the site, which was drained by a river, and 
 dotted with several lakes, all of which are mentioned 
 by some of the Roman writers. This marsh-land was 
 connected with North Holland by a narrow isthmus, 
 which was cut away in the thirteenth century by the 
 action of the waves, and a considerable portion of the 
 neighbouring country was submerged beneath the sea. 
 It was on this occasion that the Zuyder-Zee was formed. 
 Very probably had Holland not been inhabited by 
 such a brave and persevering race, it would long ago 
 have become the prey of the sea. First of all it would 
 have been split up into 'islands, like a neighbouring 
 country, and afterwards these islands would have been 
 slowly worn away. Who has not heard of the toil- 
 some battlings of its brave and hardy sons in disputing 
 the right of the ocean ? It has ever been their con- 
 stant foe, and has threatened their .country with de- 
 struction from time immemorial ! Goldsmith has 
 enshrined their hardy perseverance in our literature : 
 
POPULAR GEOLOGY. 43 
 
 " To men of other minds my fancy flies ; 
 Imbosomed in the deep where Holland lies, 
 Methinks her patient sons before me stand, 
 Where the broad ocean leans against the land, 
 And, sedulous to stop the coming tide, 
 Lift the tall rampart's artificial pride. 
 Onwards, methinks, and diligently slow, 
 The firm connected bulwark seems to grow ; 
 Spreads its long arms amid the watery roar, 
 Scoops out an empire and usurps the shore. 
 While the pent ocean, rising o'er the pile, 
 Sees an amphibious world before him smile, 
 The slow canal, the yellow- blossomed vale, 
 The willow-tufted bank, the gliding sail, 
 The crowded mart, the cultivated plain 
 A new creation wrested from his reign !" 
 
 Along the coast of North America the sea has also 
 made considerable inroads. In some places the 
 amount of land which has been wasted has averaged 
 nine feet in a year ; and, at the entrance to the har- 
 bour of Charlestown, in South Carolina, in the three 
 years ending 1786, the sea carried away a quarter of a 
 mile of land ! 
 
 But this wasting of the coast-line, which is not 
 peculiar to one locality, but goes on more or less along 
 the shores of every country in the world is counter- 
 balanced by the addition of new land elsewhere. 
 Sometimes the muddy sediments, brought down by 
 rivers, will settle down at their mouths, and form bars 
 and banks, similar to that of the Mersey at Liverpool 
 whilst in other localities this matter is strewn far 
 and wide over the bottom of the sea, and in this 
 manner forms deposits of sand and rock. There is a 
 current in the Mediterranean which, though it wastes 
 
44 POPULAR GEOLOGY. 
 
 some parts of the African coast prevents the growth 
 of the delta of the Mle, by carrying the sediments 
 brought down by that river, to the east, and laying them, 
 down upon the Mediterranean floor. The Amazon is 
 said to rush into the sea with such force, that its 
 waters remain unmixed with those of the ocean for a 
 distance of three hundred miles carrying the materials 
 which it has brought down, and strewing them over 
 the bottom of the Atlantic. The great Bahama banks, 
 off the Bahama islands, have been formed by the waste 
 of the American coasts, and probably by the sediments 
 carried down by the Mississippi. Now in extensive 
 and shallow seas, into which numerous rivers empty 
 themselves, the sediments which are carried in will, in 
 time, fill up their basin. Thus the sea of Azof, which 
 everybody heard of during the Crimean war is being 
 gradually filled up by the muddy matters carried into 
 it by the Don ; and at the present time, the average 
 depth is only about six or seven fathoms. In the time 
 of Aristotle this fillirig-up process was going on, for we 
 find that philosopher making mention of the circum- 
 stance. The Yellow sea, an arm of the Chinese ocean, 
 takes its name from the muddy waters which are 
 poured into it by its tributary rivers, and this sea is 
 also becoming shallower. The Hoang-Ho, one of the 
 largest rivers in China, empties itself into it, and it 
 has been estimated that the quantity of mud which 
 this river brings down is so great that it would convert 
 a square mile, one hundred and fifty feet thick, into 
 solid land in seventy days. When Captain Hall, of 
 the Lyra, sailed through this sea, in 1816, he had only 
 
POPULAK GEOLOGY. 45 
 
 about five fathoms of water under his vessel ; and in 
 many places he found that the ship's bottom was 
 actually trailing in the mud, for it left a long 
 wake of yellow water behind it. This occurred 
 when no land was visible from the mast head of the 
 vessel. 
 
 In the time of the Eomans, the Isle of Thanet, in 
 Kent, was, as its name implies, a real island, and was 
 separated from the mainland by a navigable channel 
 through which the Roman fleet sailed in their voyages 
 to and from London. Since then this channel has 
 been filled up, and it now exists, in many places, as 
 marsh land, watered by a few small streams. In the 
 Adriatic a strip of new land, a hundred miles in length, 
 and from one to twenty in breadth, has been added by 
 the material brought down by the Po and Adige. The 
 town of Adria, which gives its name to the sea, was a 
 seaport in the time of the Romans, whereas it is now 
 some twenty miles away. In many places round the 
 British islands shell-marl is forming, as in the Isle of 
 Man, near Castletown, where it is composed of trochi, 
 littorinae and purpurea and in the British channel, 
 off Brighton, as well as in other places off the Kentish 
 coast. The shell-marl obtained from the latter localities 
 is of such a solidity and hardness that it will bear 
 cutting and polishing, like the Derbyshire marble ; 
 extensive beds of this material, composed of scarcely 
 anything else but common cockle-shells, are found on 
 the sea-bottom near the mouth of the Thames. 
 
 Out in the deep sea there are vast deposits of pasty 
 mud forming along the bottom ; and almost wherever 
 
46 POPULAR GEOLOGY. 
 
 the sounding-lead has been let down it has brought up 
 this mineral matter. But what is more astonishing is 
 the fact that it is composed of scarcely anything else 
 than the remains of foraminifera, or the thin shells 
 which cover the minute bodies of animalcule ! 
 Soundings in the Gulf-stream, off Florida, in depths 
 varying from one hundred and forty-seven fathoms to 
 two hundred and hve have brought up this light 
 greenish grey mud, chiefly composed of diafomacea, 
 and foraminifera, the latter greatly predominating. 
 The only inorganic matter which was mixed with this 
 mud was quartz sand, in small proportions. In the 
 Baltic these animalculic shells abound in such quan- 
 tities as to block up some of the harbours and ports. 
 Great additions of new land have taken place along 
 the coasts of France since the time when Csesar con- 
 quered it. Some of the harbours and ports mentioned 
 by the Roman writers, are now far inland. Nay, so 
 rapidly has land been added, that in one locality, a 
 town which was erected along the sea-side so late as 
 1737 is now more than a mile distant from it. This 
 formation of modern deposits is not limited to the sea, 
 for they are also taking place along the bottoms of 
 existing lakes, and present similar features to those 
 which are met with in beds of similar origin belonging 
 to the Tertiary period. Thus the currents which 
 traverse the waters of Lake Superior, in so many 
 directions, spread the mud along its bottom. And it 
 has been ascertained by soundings that it is covered by 
 a fine adhesive clay, containing shells of the same 
 species as those which now inhabit the waters. When 
 
POPULAR GEOLOGY. 47 
 
 this clay has been exposed to the air for a time, it 
 become so hard as to be broken only with a hammer. 
 The colour varies, just as we see it does in rocks of 
 the same age for in some places we find the mud red, 
 in others blue, and sometimes of an appearance similar 
 to pipe-clay. JSTow such processes as these prove, most 
 evidently, how deposits, of a vastly greater antiquity, 
 have been elaborated ; and furnish to the geologist the 
 only true key to the interpretation of the phenomena 
 of his science. 
 
 Whilst we are dwelling upon the manufacture of 
 new lands from the waste of the old, it behoves us, 
 necessarily, to take into consideration the vast im- 
 portance which has been exercised by organic forces. 
 In addition to the extensive beds of calcareous mud 
 which have been formed along the ocean-floor by 
 animalculic agency, there are other families of creatures 
 at work, producing analagous results. And, when we 
 take into consideration that all these results have been 
 obtained from the almost inappreciable quantity of 
 solid matter which is held in solution by the water 
 we may well be truly astonished ; for it is a well- 
 known fact that the anthozoa, or corals, and others of 
 a similar class, can only exist where the waters are 
 most free from muddy impurities. Off the Bermudas 
 there are, in course of formation, huge banks of ser- 
 pulidce, the calcareous cases of marine worms, and 
 these deposits, we learn, are almost equal in their 
 solidity and extent to the coral-reefs of the neighbour- 
 ing seas. But, far above all the rest, the anthozoa, or 
 corals, hold the highest importance, on account of the 
 
48 POPULAR GEOLOGY. 
 
 extensive results of their labours. The substance 
 called " coral " was generally deemed to be of vegetable 
 origin until the year 1720, when a French naturalist, 
 M. de Peyronnel, commenced a series of observations 
 extending over a period of thirty years, and succeeded 
 in demonstrating it to be the production of a living 
 animal belonging to the Polypi family. Masses of this 
 coral-rock occur in the Indian and Pacific oceans, far 
 away from any land, and some of them are found ex- 
 tending over spaces of four and five thousand miles in 
 length, by fifty and- sixty in breadth. Along the coasts 
 of Australia there are coral-reefs more than a thousand 
 miles long, and averaging fifteen in width. Not only 
 have we these rock-masses as the result of vital agencies 
 but we find them giving rise to another series of 
 deposits. Thus the action of the waves upon them 
 breaks them into fragments, and grinds them into 
 powder, so that, at low water, the surface often pre- 
 sents the appearance of ordinary limestone, and wh n 
 hardened, can even be broken up into slabs. In 
 addition to this, great quantities of the limy mud 
 abraded by the action of the sea is carried away and 
 strewn along the adjacent ocean-floor, where it forms 
 beds of impalpable limy mud. In the Pacific Captain 
 Beechey examined thirty-two coral-islands, of which 
 the largest was thirty miles in diameter, and the 
 smallest rather less than one. But there is a vastly 
 important and interesting circumstance in connection 
 with the labours of this little animal. Mr. Darwin, 
 in his work on " Coral-reefs," has shewn that in those 
 seas where they occur, there must be a slow and 
 
POPULAR GEOLOGY. 49 
 
 gradual sinking of the whole area, for these animals 
 cannot live at a greater depth than thirty fathoms. 
 The whole of the Pacific islands, therefore, are the 
 lingering remains of an old continent which has sunk 
 beneath the waters, leaving the hills and mountains, 
 like the masts of a foundered ship, to serve as founda- 
 tions for the anthozoa to build up their reefs, and thus 
 rescue vast portions of solid land from the ravages of 
 the sea ! It is not always to the grand and sublime 
 that we must look for the most important results. 
 Good old Jeremy Taylor used to say that " a fly, with 
 God's message, could choke a king," and we have seen 
 that at the same bidding a continent is rescued from 
 the ocean, and peopled with animal and vegetable life ! 
 Great and important physical changes are also in- 
 duced by plutonic agency, by the action of forces 
 seated, not on the surface, but deep within the interior 
 of the earth. To this agency we must ascribe the 
 elevation and depression of land, earthquakes, volcanic 
 action, &c. The number of these disturbances is far 
 greater than we have been in the habit of considering. 
 Professor Ansted states that " more than sixty earth- 
 quakes have taken place on an average in each year ; 
 and of this number, about three in two years, or one 
 every eight months, has been what may be called a 
 great earthquake by which is meant one in which 
 whole cities and towns, or large portions of them, have 
 been reduced to rubbish, and many lives lost." In 
 the year 1811-12, part of the Mississippi valley was 
 submerged by an earthquake shock, and has since gone 
 
50 POPULAR GEOLOGY. 
 
 by the name of the "sunk country." Sir Charles 
 Lyell states that when he visited it he observed erect 
 trees, which had been standing ever since the disturb- 
 ance took place, and which were now surrounded with 
 morasses and lagoons. During the great earthquake of 
 Calabria, the quay of Messina sank fourteen inches, 
 and vast masses of the sea-cliff were detached by the 
 shock and thrown into the sea. Within the modern 
 period the coasts of the bay of Fundy, Nova Scotia, 
 have been submerged ; and trunks of pine and birch, 
 which not long ago grew upon the solid dry land, may 
 now be seen, at low water, covered with the sea. 
 Owing to the phenomenon being repeated in every 
 geological work, it is now a well-known fact that the 
 shores of Greenland are gradually subsiding at the rate 
 of about three feet in a century ; while the whole 
 area of the south Pacific has been, more or less, under- 
 going the same operations. In 1854, when Mr. Saw- 
 kins visited the island of Tongataboo, one of the 
 Friendly Islands, he found that it had recently been 
 visited by an earthquake, which had tilted down the 
 north-east portion "so as to cause an encroachment of 
 the sea for two miles inland ; whilst the western coast 
 had risen some feet." On the whole, however, it 
 would seem that the process of upheaval predominates 
 over that of depression ; while geological facts seem 
 to indicate that this has been the case during many 
 of the geological periods. It is possible that the cause 
 of many of these local upheavals and depressions may 
 be assigned to the fluctuation of the temperature in 
 
POPULAR GEOLOGY. 51 
 
 the heated interior of the earth. When great acces- 
 sions of heat rise to the solid crust they would cause it 
 to shrink, and so produce a depression of the surface, 
 or to expand, and thus cause an upheaval. Hum- 
 boldt has shown that if a stratum of sandstone-rock 
 of five miles in thickness should have its temperature 
 raised about a hundred degrees its surface would rise 
 twenty-five feet. On the contrary, heated beds of 
 clay or shale would occasion a depression, and perhaps 
 a submergence, by the shrinking and contracting of 
 the mass. Sometimes these elevating forces are very 
 gradual in their operations, whilst occasionally they 
 are also violent and sudden. An elevation of the 
 Chilian coast took place in 1822, which extended over 
 an area of a hundred thousand square miles ; and in 
 some places the shores were raised from three to seven 
 feet above their former * level. On account of this 
 sudden upheaval, for it took place in a single night) 
 a great part of the sea bottom was laid bare, so that 
 the beds of oysters and mussels could be seen adhering 
 to the rocks upon which they had grown. 
 
 An upward movement of the land has been proved 
 to be now going on in Sweden and Norway throughout 
 an area of more than a thousand miles, north and 
 south; the distance east and west not being known. 
 The elevating force seems to increase as we proceed 
 towards the North Cape, where it averages about five 
 feet in a century. Near Stockholm, the capital of 
 Sweden, there are beds of sand and marine shells of 
 similar species to those now living in the waters of the 
 
 E2 
 
52 POPULAR GEOLOGY. 
 
 Baltic, along with the remains of rude works of 
 art the whole of which are found sixty feet above 
 the level of the sea. On the opposite coast of Sweden, 
 at Uddevalla, beds containing the same kind of shells 
 as those now inhabiting the Northern Ocean are found 
 at an elevation of two hundred feet ; and in Norway 
 strata of the same age are found as high as seven hun- 
 dred feet above the level of the ocean where they were 
 originally imbedded. These upward movements have 
 gradually and constantly acted until these beds have 
 attained their present height, and, doubtless, at the 
 same rate of elevation at which they are now rising ; 
 and yet the whole phenomena have been effected dur- 
 ing the life-time of existing species of shells ! Similar 
 raised beaches are found along the coast of Chili and 
 Peru, at an elevation of eighty-five feet and yet this 
 can be proved to have taken place since the country 
 was peopled with the Peruvian race. In like manner, 
 along the coast of Australia upheavals have taken 
 place j and within a very recent period some parts 
 have been elevated from five to ten feet, Again, it is 
 a well-known fact that since the human period began, 
 many parts of the Scottish coast have been upraised, 
 in some places as much as fifteen feet. These move- 
 ments, however, like those which have taken on the 
 Baltic coasts, have not been effected at once, but gradu- 
 ally, and in some places there are two or three beaches 
 like terraces, one above another. Nay, so numerous 
 are the old beaches, and so common, that they form a 
 very prominent feature in the scenery of the Scottish 
 
POPULAR GEOLOGY. 53 
 
 Coasts. The skeleton of a whale, seventy-two feet in 
 length, has been found imbedded in the clay along the 
 banks of the Forth, more than twenty feet above the 
 reach of the highest tides. Similar remains have also 
 been found in Stirlingshire more than forty feet above 
 the present sea level. " These whales," says Hugh 
 Miller, " must have been stranded when the old coast- 
 line was wasted by the waves, and the marginal strip 
 existed as an oozy sea-bottom ; and yet, in both cases, 
 there were found among the bones, primitive weapons 
 made of pointed branches of deer's horns, hollowed at 
 their broad ends by artificial perforations ; and in one 
 of these perforations the decaying fragments of a 
 wooden shaft still remained." Mr. Geikie, of the 
 Geological Survey, has recently shown that since the 
 erection of Adrian's wall, the neighbouring coasts have 
 been elevated several feet. 
 
 It will be evident to all, that forces which are thus 
 able to heave up continents with chains of mountains 
 like the Andes upon their backs, are equal to the 
 upraising of islands from the bottom of the sea, as 
 well as of mountain chains. Who has not heard of 
 the upheaval of the plains of Jorullo in 1759 1 ? As a 
 writer observes, " It is seldom that we find Nature in 
 the act of forming a mountain ;" but here is an instance. 
 The plains of Malpays had been famous for years on 
 account of their fertility, and were covered with plan- 
 tations and watered by several streams ; but one night 
 in June, the whole of these plains were upraised above 
 seventeen hundred feet in height, and fifty cones burst 
 
54 POPULAR GEOLOGY. 
 
 out with floods of molten matter. It is said that the 
 heat thus emitted was so great as to render the sur- 
 rounding country uninhabitable for the next fifty years. 
 But within the sphere of human observation, nature 
 has been more prolific in creating islands than in 
 forming mountains ; indeed islands themselves are but 
 the mountain peaks of submarine lands ! Several of 
 the largest islands in the Greek archipelago owe their 
 origin to plutonic action, as Santorin and several others. 
 In 1814 a new island was formed among the Aleutian 
 group, in the North Pacific, which rose up to the 
 height of three hundred feet; after this upheaval it 
 subsided for a time, but shortly afterwards settled itself 
 down as a member of the group. A similar one was 
 produced in 1783, about seventy miles from Iceland, 
 Its elevation above the sea was attended with the ejec- 
 tion of such a quantity of light ashes that the surface 
 of the sea was covered with them to the distance of 
 one hundred and fifty miles, whilst they lay so thickly 
 upon the water that even ships were impeded by them 
 in their course. This island rose sheer out of the 
 ocean, its steep cliffs being prominent features, whilst 
 from the summit, in several places, there were emitted 
 fire and smoke. Shortly after it was claimed by the 
 King of Denmark, who named it the "New Island" ; 
 but, before a year had elapsed, the newly annexed land 
 had subsided beneath the waves, and the sea had re- 
 sumed its reign. At the present time there is only a 
 reef of dark rocks lying just above the water to mark 
 the spot where an island lately foundered ! Since 
 
POPULAR GEOLOGY. 55 
 
 1538, several islands have been formed among the 
 Azores through similar agency, some of which have 
 since disappeared. In 1831 a volcanic island sud- 
 denly made its appearance off the coasts of Sicily, 
 and was called "Hotham Island," after the name of the 
 English admiral who furnished the world with the 
 intelligence. Ascension Island takes its name from 
 first appearing above the sea on that day in the year 
 1501. And so recently as 1853 a new island appeared 
 in the South Pacific, not far distant from Tahiti. 
 Perim, in the Red Sea, is the result of a volcanic 
 eruption beneath the water; and now it has made 
 its appearance as dry land, it is singular how well 
 geology enables the student to read the history of 
 its formation. First of all, the lavas have raised the 
 sea-bottom, when it was covered with a thick growth 
 of coral, and during this operation much of the coral- 
 rock has become embedded in the molten paste. After- 
 wards the lava has forced for itself a passage, and at 
 length appeared above the sea-level; and now this 
 submarine volcano, of which the crater corresponded 
 to the whole bay of Perim, has been for some time in 
 activity, and has covered the island with mud, ashes, 
 and scoriae, and last of all with the hard trachytic rock 
 which overlies the whole. The volcanic action now 
 ceased, and a submergence took place, when a cal- 
 careous sandstone was formed ; at length a gentle up- 
 heaval elevated the whole above the waves, and since 
 then the island has presented its present appearance. 
 These facts, which were collected by M. Courban, 
 
56 POPULAR GEOLOGY. 
 
 prove that the Eed Sea, which forms one of the most 
 marked localities on the surface of the globe, bears 
 traces throughout all its length of eruptive phenomena 
 of immense extent, and of an age certainly not very 
 remote from the present epoch. Such are a few of the 
 phenomena which have resulted from vole mic forces 
 acting from the interior upon the outer crust of the 
 earth. How many of these submarine elevations have 
 taken place which have not yet appeared above the 
 water, we cannot say, but judging from what we know 
 of the nature of these agencies, there would be no 
 rashness in asserting that there are many. Now, were 
 the waters of the ocean to be withdrawn, so that we 
 could see the vast plateaux which form its bottom, 
 these islands would then appear as high hills and 
 mountains, rising with steep and rugged sides from the 
 dreary wilderness below. 
 
 There are other extensive phenomena, that now form 
 part of the physical scenery in various parts of the 
 globe, which are also due to plutonic agencies. The 
 various volcanic cones, the safety-valves of our world, 
 which allow the high pressure of its heated nucleus to ob- 
 tain legitimate outlets, and 'which belt the earth by their 
 zones are all due to elevating forces acting in a similar 
 manner to that which upheaved Jorullo and which 
 still elevates new islands above the sea-level ; or to suc- 
 cessive layers of erupted matter which have accumu- 
 lated along the crater side, until they have grown into 
 mountains. It would appear from recent investigations 
 that most of the volcanic mountains have been formed 
 
POPULAR GEOLOGY. 57 
 
 by the latter process. But besides the layers of matter 
 which have flown down the sides of mountains, and 
 increased their size, streams of molten lava often flow 
 over very extensive areas of the land below, and even 
 into the sea, and when they have subsequently cooled 
 down they form layers of massive rock. In 1739 
 Vesuvius emitted a stream of lava which was calculated 
 to contain upwards of thirty-four millions of cubic 
 feet; and in 1794 another current was discharged 
 which contained above forty-six millions of cubic feet of 
 matter. Only recently this very mountain vomited 
 forth its fiery matter, and desolated villages and towns 
 with its poisonous gases and showers of dust. Again, 
 in 1669 Mount Etna is known to have emitted above 
 ninety-three millions of cubic feet of lava ; while the 
 sand and scoriae thrown up formed a mound two miles 
 in circumference and four hundred and fifty feet high. 
 It is estimated that the mass of matter discharged 
 by an Iceland volcano the Skapter-jokul, in 1783 
 was greater in bulk than Mont Blanc, and that 
 "if spread over the coal-fields of great Britain it would 
 cover them with a coating of basaltic rock twenty feet 
 thick." 
 
 Thus, a knowledge of existing causes and eifects, 
 and of the various relationships which exist in the 
 physical world, enables the geologist to reason concern- 
 ing the various phenomena which are presented to him 
 in the rocks. They tell him under what circumstances 
 such a bed was formed, and by what agency, and when 
 it was upheaved from its original horizontal position ; 
 
58 POPULAR GEOLOGY. 
 
 under what conditions a certain layer was deposited ; 
 whether it was the result of volcanic matter spread out in 
 molten sheets on the old sea-bottom, or was formed by 
 the settlement of volcanic ashes and scoriae. Nay, a 
 knowledge of existing Nature in her many depart- 
 ments becomes absolutely necessary to enable the 
 geologist to state under what conditions ancient life 
 was enjoyed, and how climates were affected by the 
 different distribution of warmer currents of water. If 
 the mountains of those early times were higher or 
 lower than they are at present, he knows from the 
 manner in which climates are affected by them now, 
 that they must have exercised a similar influence then. 
 Even from the distribution of the old land and water 
 the geologist can tell something of the nature of 
 the climates which would result from such conditions 
 were the main- land to be connected with an arctic 
 continent, he knows that cold would be conducted to 
 the equatorial latitudes ; while if the whole were to 
 form a thickly-scattered archipelago of islands, though 
 the temperature of the summer would not be so high, 
 the winter would be more genial, and thus a more 
 equable temperature would be the result. Such con- 
 ditions as the latter would be most favourable to vege- 
 table growth, as if is evidenced by similarly-situated 
 islands in the South Pacific. Nay, there are some of 
 our leading geologists who hold the opinion that the 
 present condition of the Malay archipelago, with its 
 numerous large islands, separated by wide and shallow 
 seas, most probably represents the former state of 
 
POPULAR GEOLOGY. 59 
 
 Europe when most of the Palaeozoic and secondary 
 formations were accumulating. Again, from a know- 
 ledge of the habitats, or natural abodes of existing 
 animals, and especially of fishes and shells, the geolo- 
 gist is enabled to state under what conditions many of 
 the rocky strata were deposited whether they were 
 formed in shallow or in deep water far off from land, 
 or near to the shore. And it has been recently estab- 
 lished as a geological fact, that on equal areas the 
 average number of shallow-sea inhabitants are eight 
 times more numerous than those which inhabit deeper 
 waters. Now it is from understanding these habitats 
 that we come to the conclusion that some fossils are 
 extraneous to the beds in which they are found, that 
 is, that some of them have been carried to a distance 
 by the currents which agitated the seas in which they 
 lived. For instance, corals are not found in muddy 
 waters, but abound in the clearest, consequently, when 
 we find such fossils in argillaceous deposits, they must 
 have either been carried and rolled there, or have been 
 suddenly buried by a discharge of mud from some 
 neighbouring land. In like manner the fossils of the 
 Encrinite family aifect similar conditions, and while 
 their remains build up whole masses of calcareous 
 rock, very few are found in shale or sandstone. At 
 Castleton, Derbyshire, the rock is so full of these fossil 
 remains, that they form " encrinital marble," and the 
 black Yoredale shales, which overlie them, contain in 
 their low-bedded parts rolled fragments of encrinital 
 stems, which had been washed out of the older rock 
 
60 POPULAR GEOLOGY. 
 
 into the newer. And in the Bradford clay of the 
 oolite formation, there is a fossil forest of apiocrinites, 
 which once grew along the clear sea-bottom, but were 
 destroyed and buried by a torrent of mud which swept 
 over them. Nay, from the distribution of some beds, 
 the geologist can infer the set of the currents which 
 swept across the pre-adamite seas ; and in this manner 
 the mineral changes which are often seen in beds of 
 the same age, are assigned to the same agencies as 
 those which we have at work along the bottom of 
 Lake Superior. Further, the geologist finds in the 
 rocks, that similar laws to those which govern the dis- 
 tribution of creature-life have been in existence from 
 the earliest times. Nay, such a faithful record is the 
 stony volume, that it tells of the habits and instincts 
 which were affected by the extinct forms of life. Many 
 of the creatures were gregarious in their habits, or 
 lived together in groups, just as they do now. Beds 
 of oysters of extinct species paved the sea-bottom and 
 there accumulated during long years, in exactly the 
 same way as their representatives do now. Other 
 animals which were not so fixed in their habits, such 
 as the terebratula and lingula, still lived in small 
 groups or families. And it is owing to this circum- 
 stance that many local beds take their names. Hugh 
 Miller remarks that so early as the Devonian period 
 the mail-clad fishes had their feeding and spawning 
 places, as fishes have now. In the times of the Lias, 
 the representative of the oyster, the gryphea, lived in 
 beds along the bottom of its seas. Some of the large 
 
POPULAR GEOLOGY. 61 
 
 crustaceous animals which lived in the Silurian seas 
 have even left behind them their fossil spawn; and 
 the reptiles of the oolite have left their eggs petrified 
 in the rocks. There is not a single circumstance which 
 I have just recorded that is not analogous to the 
 habits of the representatives of these creatures, which 
 live in modern seas. Nay the five great divisions 
 into which naturalists separate the living world, are 
 found represented in rocks of almost every age ; 
 and nowhere does the geologist find that Nature 
 has departed from a uniformity of working. All 
 these facts prove that, like her Governor and 
 Lord, Nature knows "no variableness nor shadow 
 of turning ;" but is " the same yesterday, to-day, and 
 or ever." 
 
 Now we know from undoubted information that 
 climates are influenced in a very great measure by the 
 streams of warm or cold water which agitate the sea, 
 and which sometimes move vast bodies of water from 
 one hemisphere to another. At the present day there is a 
 current of warm water, a thousand times greater in 
 volume than the Mississippi, which sets out from the 
 Gulf of Mexico and crosses the Atlantic. Captain 
 Maury calculates that the quantity of heat which it 
 discharges over the Atlantic on a winter's day, would 
 be sufficient to raise *the whole column of atmosphere 
 that rests upon France and the British Islands from 
 the freezing point to summer heat. It is, says he, the 
 influence of this Gulf- stream that makes Ireland the 
 " Emerald Isle of the sea/' and that "clothes the shores 
 
62 POPULAR GEOLOGY. 
 
 of Albion in evergreen robes," while on the American 
 side of the Atlantic the want of this warm current 
 causes the shores of Labrador to be bound in fetters of 
 ice. Nay, while the port of Liverpool is open the 
 whole year, the harbour of St. John's, Newfoundland, 
 although a geographical degree more south than it, has 
 been closed with ice as late as the month of June. 
 Here we see that if the narrow isthmus of Panama, 
 which is only some forty miles in breadth, were to be 
 submerged so as to allow the waters of the Pacific to 
 flow into the Atlantic, the Gulf-stream would be de- 
 stroyed, and the seas of England and Europe would be 
 girt with ice-bound shores ! 
 
 Now if geology teaches anything, it is that the dis- 
 tribution of land and water in former times was very, 
 different to what it is now. Consequently, according 
 to this distribution the ancient climates must have 
 been more or less related. It is from a consideration 
 of these circumstances, that Sir Charles Lyell affirms 
 the existence of a much warmer climate during the 
 carboniferous period, and of a cold one during the 
 later tertiary. 
 
 Another geological fact, one of the most prominent 
 which is deduced, is that of the extinction and crea- 
 tion of genera and species. Now this is a process 
 which at first thought is somewhat startling, yet it is 
 one which has taken place within historic times. Thus 
 the dodo, a large pigeon of the Isles of France 
 and the Mauritius, has become extinct since the six- 
 teenth century. In New Zealand the dinornis, another 
 
POPULAR GEOLOGY. 63 
 
 large bird of the same family as the ostrich, but much 
 larger, has been annihilated by the present aboriginal 
 race. Even more has civilized man done his part in 
 this respect, for the spermaceti whale, owing to its 
 being hunted for its oil, is fast merging into extinction. 
 The great auk is also dying out ; and the brachiopo- 
 drus family of shells, which has been in existence from 
 the earliest times, has during the latter geological 
 periods been gradually dwindling awayj while the 
 nautilus family, once so abundant in species, is now 
 represented by only one. Again, the auroch, a large 
 bison which still roams in the wild forests of 
 Lithuania, and a gigantic ox nearly as large as 
 an elephant, both lived in England at least two 
 thousand years ago. Beavers lived among the Highland 
 glens as late as the year 1526, and in Wales until 
 the twelfth century ; and we are told that it was not 
 until the year 1680 that the last wolf was killed in 
 the Highlands. The land-snails of St. Helena are sup- 
 posed by Mr. Darwin to have become finally extinct 
 only during the last century, owing to the destruction 
 of the native woods by the introduction of goats and 
 swine. In the extensive peat-bogs of Ireland large 
 forests are sometimes found buried, together with the 
 skeletons of the elk, deer, and often the bodies of the 
 primitive hunters enwrapped in skins. Who has not 
 heard of the venerable cedars of Lebanon famous to 
 us all through their connection with Scripture history, 
 and the glowing passages of the Hebrew poets of which 
 they form the subject ! And yet this species is fast 
 
64 POPULAR GEOLOGY. 
 
 becoming extinct in its native locality. It is indige- 
 nous only in Syria, where in the time of Solomon it 
 formed' grand and extensive forests, which were made 
 to ring with the plying of the Tyrian axe, previous to 
 their transfer to Jerusalem. When Ballanius visited 
 the site of these forests in 1550, there were only 
 twenty-eight of the old race remaining. In 1575 
 Runwolf found twenty-four; in 1680 Dandini found 
 twenty-three; in 1738 Pocock counted fifteen; in 
 1811 Burchardt could only number eleven; and as 
 late as 1828 Lamartiiie found but seven trees of this 
 venerable family remaining. 
 
 The extinction of species is more a matter of history 
 than their creation. Man, upon his introduction to a 
 country, would become acquainted with its animals, 
 and consequently would sooner miss one of them. But 
 this cannot be said of new introductions. It is only 
 quite recently that natural 'history has sent forth her 
 observers ; and the catalogue of existing animals and 
 plants is still far from being completed. When a fresh 
 animal or plant is recognised, it is set down as a newly- 
 discovered one, not as a newly-created one ! But who 
 can tell whether some of these so noted, might not 
 be classed under the latter, rather than under the for- 
 mer term ? Considering the present epoch only as one, 
 and the most recent of a series, we know not only, as 
 I before stated, that some families are passing into ex- 
 tinction, but that others are passing upwards to a 
 maximum of existence. Thus the family of pouched 
 animals, of which the opossum and kangaroo are ex- 
 
POPULAR GEOLOGY, 65 
 
 ainples, came into existence in the Oolitic, and perhaps 
 as far back as Triassic times, and is now more numerous 
 in species than it has been since its creation. The same 
 law characterizes the monkey tribe, that of the bat, 
 and that of the whale. And there may be much truth 
 in that theory of Darwin's which gives to created 
 forms a certain pliability to adapt themselves to the 
 several circumstances of their existence. Nay the very 
 indefiniteness of the term "species" is far from en- 
 abling us to arrive at the conclusion that each has been 
 a distinct and separate act of creative power. We find 
 many naturalists ranking " varieties " of animals or 
 plants as species; whilst others retain them as only 
 the result of accident. And, after all, it may be pos- 
 sible that since the introduction of man the Creator 
 has elevated accidental varieties of animals and plants 
 into distinct species, and thus have carried on the work 
 of His creation ! 
 
 All the phenomena of anterior epochs find their 
 analogies in the present time, and vice versa,. Thus the 
 denuding action of the waves must have been as powerful 
 and as constant in every geological period as it is now. 
 The phenomenon of extensive denudation cannot fail to 
 strike the attention of the geological student in his 
 first essays; for, just as every formation is the result 
 of deposition of the gradual settling of muddy mat 
 ter in like manner it is the result of " wear and tear " 
 of the old lands. Professor Kamsay has shown that 
 strata have been denuded from the top of the Mendips 
 of nearly a mile in thickness ; and that considerable 
 
 F 
 
66 POPULAR GEOLOGY. 
 
 areas in South Wales have had Palaeozoic rocks stripped 
 off to the depth of eleven thousand feet. In the Isle 
 of Man there has been upwards of a mile of solid 
 rock cut away during the slow uprising of the land ; 
 and in the Newcastle coal-district, faults of a thousand 
 feet in vertical displacement occur. In Lancashire, if 
 all the faults were mapped out, it would form a perfect 
 chaos; and yet the surface is seldom affected in its 
 aspects by these convulsions, owing to the strata having 
 been denuded off. All this material has been carried away 
 to form rocks of later age ; and thus we find pebbles 
 of Silurian rocks entering into the composition of 
 Devonian strata, and pebbles of Devonian rocks with 
 their characteristic fossils forming a great part of car- 
 boniferous, triassic, oolitic rocks. And thus, as Mr. 
 Page observes, " the agencies that now operate on and 
 modify the surface of the globe ; that scoop out valleys 
 and wear down hills ; that fill up lakes and estuaries, 
 and seas ; that submerge the dry land, and elevate the 
 sea-bottom into new islands ; that rend the rocky crust 
 and throw up new mountain chains ; and that influ- 
 ence the character and. distribution of plants and 
 animals are the same in kind, though differing, it 
 may be, in degree, as those that have operated in all 
 time past." 
 
 And thus, through all the history of our world, 
 have the same beautifully-adapted and beneficent laws 
 held sway, as those which are now in operation. And 
 just as the present system of natural laws supposes a 
 Lawgiver, so do geological facts prove that tlie, same 
 
POPULAR GEOLOGY. 67 
 
 Being held government during all past time ; and that 
 " from everlasting to everlasting " He is " GOD ! " 
 
 " My heart is awed within me, when I think 
 Of the great Miracle which still goes on 
 In silence round me. The perpetual work 
 Of Thy creation. Finished, yet renewed 
 For ever!" 
 
68 POPULAR GEOLOGY. 
 
 LECTUKE III. 
 
 ON THE PKINCIPLES OF GEOLOGICAL 
 CLASSIFICATION. 
 
 IT has been said, that if the whole of a man's life 
 could be noted down every hope and every fear, every 
 trial and every joy ; thoughts budding into action ; 
 words, with their mighty influences for good or evil 
 if we could write them all down, such a book would 
 not only be well worth the reading, but would be in- 
 tensely natural. 
 
 The ancients, with th,eir aptness in personification, 
 hit upon a beautiful thought when they taught that 
 the earth was a living thing, its ocean like a great 
 heart pulsating; and the atmosphere, in its varying 
 changes from calm to storm, the breath of this mighty 
 being. If the earthly probation of one of its inhabit- 
 ants, extending at most over a period not exceeding 
 three score years and ten, would form no uninteresting 
 subject what must the life-history of our world be 1 
 
 
POPULAR GEOLOGY. 69 
 
 If we could but express in language clear and simple 
 all its phenomena, its connection with the sister bodies 
 which, like it, revolve through space ; if we could 
 begin where its Creator began, and trace his footsteps, 
 such a book, whilst it would form a revelation of 
 Divine wisdom and power, would also fulfil the ends 
 of all true science. 
 
 Nothing is more true than to say that the various 
 sciences which are now in existence, and known as 
 they are by their various names, have each their pecu- 
 liar province. And yet, whilst dealing with their sub- 
 jects, it is also true that no science has a marked horizon. 
 We can hardly say this is geology, this is chemistry, 
 or this is botany ; all sciences are so nearly allied, and 
 so necessary to each other, that the boundary loses 
 itself, and we find that each is a part of one grand 
 scheme. Hence a knowledge of all existing sciences, 
 on this principle of their affinity, is a knowledge of 
 nature, so far as it is yet known. " Such knowledge," 
 however, is too wonderful for us; we cannot yet 
 " attain unto it." So that it is wise for each workman 
 to labour in his allotted province, until the time shall 
 come when the key to the storehouse of facts shall be 
 produced, until the laboured stones of centuries be 
 built up into one grand temple of nature ! 
 
 Whilst other divisions of human knowledge throw 
 light upon existing relations, it is the province of the 
 geologist to interpret the history of the past; and that, 
 too, by the characters which Nature herself has in- 
 scribed upon the rocks. Through this natural mode 
 
 
70 POPULAR GEOLOGY. 
 
 of interpretation, the world's past life is brought to 
 light, and the great truth is forced upon the mind, 
 that the present period is not the first in the earth's 
 history, hut the last of a series, which may be traced 
 backwards into the dimness of the past eternity. 
 
 Just, therefore, as the hieroglyphs inscribed upon 
 the pillars of Nineveh have furnished to us portions 
 of its history, in like manner the fossil remains found 
 in the earth, when properly understood, serve as a 
 language which enables us to understand the circum- 
 stances that prevailed in ages long anterior to the 
 creation of man. 
 
 One of the old puritan divines used to say that 
 " God's providence, like the Hebrew language, must be 
 read backwards." This is the way in which geological 
 facts are to be read ; and therefore, before we can 
 reason upon the past, we must know something about 
 the present. 
 
 These few remarks lead me to notice the manner in 
 which to treat upon the world's past history namely, 
 from what we know of the various changes which 
 have taken place within historic times, and which are 
 still in progress ; and also from the records which have 
 been preserved in Nature's own museum. Now the 
 slightest attention, bestowed upon rocks containing 
 fossils, will show that such rocks are composed of 
 layers of various thicknesses, some being several feet, 
 and others of the thinness of a sheet of paper; and 
 yet fossils are to be seen thickly scattered over their 
 various surfaces. Nay, sometimes, whole masses of 
 
POPULAR GEOLOGY. 71 
 
 rock are composed of literally nothing else than 
 these organic remains ! Now the lesson which these 
 phenomena teach is, that each layer in succession has 
 been the platform of the life which existed during that 
 period and certainly, in unravelling these mysteries 
 of bygone creations, astonishing truths and principles 
 are arrived at. 
 
 Geology, the "science of the rocks," may be said to 
 commence, or rather, to branch off from Astronomy. 
 We consider the earth as a solid, round mass of matter, 
 some eight thousand miles in diameter, and which 
 journeys around the sun at the rate of seventy thousand, 
 two hundred miles an hour, making a complete revo- 
 lution round that luminary in a year. From the science 
 of astronomy we then pass on to chemistry, which 
 enables us to consider the materials of which the 
 earth is composed. We then discover, to our astonish- 
 ment, that there have been employed in its construc- 
 tion, only about sixty simple bodies, which are in 
 consequence termed elementary ones. Of these sixty, 
 forty-three are metallic bodies, while four or five are 
 purely gaseous. It does certainly seem strange that 
 one of the commonest of these simple elements should 
 be a gas, and that this gas, more than any other ele- 
 ment besides, may be said to compose nearly one-half 
 the globe ! It is true, nevertheless ; for oxygen forms 
 nearly one-fourth part by weight of the atmosphere, 
 eight-ninths of the whole weight of water on the sur- 
 face of the globe, and nearly half of the solid crust of 
 the earth. Out of the whole of these sixty simple 
 
72 POPULAR GEOLOGY. 
 
 bodies there are only one or two which are ever found 
 in nature existing in a pure state. All of them com- 
 bine with one another, and it is their constant com- 
 bination which gives rise to some of the most remark- 
 able phenomena of our world. Further, from chemistry 
 we learn that there are none of these bodies, however 
 solid, which, by intense heat, may not be made to pass 
 off into a state of vapour. Even gold, which hitherto 
 has been supposed to withstand sublimation, is now 
 ranked with the. rest. Archimedes, upon discovering 
 the lever, said he only wanted one long enough to 
 be able to move the earth. So may we say of the 
 chemist, that with sufficient heat he could .make the 
 
 " Great globe itself, 
 Yea, all which it inherit, dissolve, 
 And like the baseless fabric of a vision 
 Leave not a wrack behind.'' 
 
 It belongs to the province of mineralogy (a know- 
 ledge of which is necessary to the elucidation of geolo- 
 gical facts) to show how these chemical combinations 
 are resolved into mineral masses. Minerals are gene- 
 rally denned to be any substance not organized by 
 vitality, and having a homogenous, or similar structure. 
 This definition distinguishes mineral masses from those 
 which have been produced by mechanical agencies, 
 such as clays, sands, &c. With geology, b t;my holds 
 a great affinity. A knowledge of this science enables 
 the student to tell from a fragment of fossil wood, a 
 leaf, or root, the class to which it belonged. Natural 
 history, in its various branches, a knowledge of the 
 
POPULAR GEOLOGY. 73 
 
 habits and instincts of animals, their geographical dis- 
 tribution, &c., also bears very importantly upon our 
 peculiar study. The fossil remains of plants and ani- 
 mals has given rise to a distinct department of geology, 
 called palaeontology, or the science of organic remains. 
 Such are a few of the existing sciences whose dis- 
 coveries bear most importantly upon geology. In 
 addition to them, since geology has arisen to so great 
 an importance, physical geography, or a knowledge of 
 the changes on sea and land, all over the globe, has 
 been more studied, and the facts which have been 
 brought to light have rendered no little assistance in 
 the elucidation of geological phenomena. 
 
 It is not one of the least interesting employments to 
 observe how science, taking it under its broadest sig- 
 nification, has had to struggle, before its principles 
 have been received as true. It seems to have been 
 ordained that " out of great tribulation" only, its pre- 
 cepts should be made known. And it is only when 
 science has passed through the crucible of opposition, 
 that it has come out as " gold, seven times purified." 
 In the struggle for truth, the human mind has been 
 engaged in one of the loftiest pursuits, and, in the 
 persevering toil which has brought her from the bottom 
 of her well, the finest faculties of man have been 
 developed. In the history of mental progress, it is, 
 further, interesting to notice how one truth, when 
 received and trusted, has served as an axiom to another 
 yet unknown ; and how, in this gradual progression, 
 truth has rallied around truth, strengthening it against 
 
74 POPULAR GEOLOGY. 
 
 the attacks of error, and drawing the line of distinc- 
 tion more clearly. It has been with all the sciences as 
 it is with individuals, before they have obtained a 
 character, they have had to earn one; and when 
 earned, this character or reputation, has been more or 
 less valued according to its importance. 
 
 This individuality of the sciences, if I may so term 
 it, is peculiar to every one of them. Why is it that 
 astronomy is so justly placed at their head ? Is it not 
 because her valuable and decisive proclamations have 
 literally forced converts, and her predictions have come 
 to pass with almost the assurance of infallibility ? It 
 was not always so with Urania. Much as she has 
 engrossed the attention of mankind, from the time 
 when 
 
 " Chaldee shepherds kept their flocks by night," 
 
 to that of Kepler and Copernicus, error had inter- 
 woven with the warp of truth a web of subtlest 
 deceit. And thus, instead of truth freeing the 
 human intellect, it formed a chain wherewith to 
 bind it. One difficulty after another sprung up to 
 bewilder the mind of students, until, more in despair 
 than in hope, they flung away their old astronomical 
 systems, and sought after a new theory which could 
 interpret known facts. To do so, however, after such 
 systems had been received by the world as established 
 truths, during long centuries, required no feeble eifort ; 
 hence we find that all the old astronomers had recourse 
 to the most extreme ideas before they gave them up. 
 Ptolemy sought refuge in his cycles and epicycles to 
 
POPULAR GEOLOGY. 75 
 
 explain the movements of the heavenly bodies ; whilst 
 others, less patient, and less informed, did not scruple 
 to refer everything which did not accord with their 
 teachings, to the influence of evil spirits. Then what 
 a flood of light burst upon the human mind when it 
 alighted upon the truth ! How rapidly the discove- 
 ries of Copernicus, and his immortal school, were 
 followed by those of Newton, Halley, and Herschel ; 
 until a few years of discoveries buried for ever the 
 notions which had held sway from the infancy of the 
 world. 
 
 In the science of chemistry, we find the same gradual 
 increase of power with its knowledge. The old al- 
 chemists were not all greedy seekers after gold. Many 
 there were, true children of nature, who burned to lift 
 the veil from the unknown, and peer into the hidden 
 causes of things. The very character which alchemy 
 had obtained, and the general belief that its votaries 
 were connected with the spii it-world, prompted many 
 to its study fancying that such connection was a sure 
 mode of gaining knowledge. In the history of alchemy, 
 fruitless though it was, we have numerous discoveries 
 which kept on accumulating through the patient pur- 
 suits of centuries, until, phoenix-like, out of the ashes 
 of a delusive science there sprung up one which should 
 influence the future industry of nations. 
 
 After the French chemists gave to the world that 
 system of classification which the science now holds, 
 its progress was rapid and sure. The right track had 
 at last been hit upon, and many crowded to plod the 
 
76 POPULAR GEOLOGY. 
 
 toilsome way. Among them we may name Lavoisier, 
 Fourier, Black. Davy, and a host of others. It is the 
 numerous discoveries which have attended the labours 
 of these men, that has served, more than anything 
 else, to rivet popular faith upon the teachings of 
 chemistry. 
 
 The same principles hold good in natural history. 
 The real discoveries of Aristotle were misrepresented 
 by his very commentators and pupils ; and the childish 
 tales of Pliny misrepresented all natural subjects. 
 These were the only authorities upon the subject for 
 centuries. It was even held by many learned men 
 that such pursuits were only fit for children, and had 
 no relation to the scholar. It is often the case that 
 two sciences, like helpmates, rise or fall together; thus 
 it is with geography and natural history. Aristotle 
 wrote when his pupil Alexander was making his dis- 
 coveries and achieving his conquests ; and Pliny when 
 Rome was mistress of the world, and the produce of 
 various nations was introduced in the capital. And 
 now, in a far later age we perceive how the discoveries 
 of the Spaniards in America, as well as the discoveries 
 of the various European nations which have followed 
 in their wake, influenced the science upon which we 
 are dwelling. Animals and plants were brought to 
 Europe by navigators, in such abundance, that curi- 
 osity became excited ; but these additional facts served 
 rather to obscure than to enlighten popular ideas upon 
 the subject. To our countryman Ray belongs the 
 honour of attempting the first classification of animals 
 
POPULAR GEOLOGY. 77 
 
 and plants, which, were afterwards developed by the 
 Swedish naturalist Linnseus. ^Naturalists were now 
 enabled to assign to every new plant or animal dis- 
 covered its position in the natural history scale, and 
 through the rare talents of Cuvier, the classification 
 became so perfect, that a newly-discovered species of 
 animal was assigned its place almost as easily as in a 
 cabinet ! In the schools of these great naturalists, many 
 observers were trained. By and bye societies sprung 
 up and fostered a general love for the science, and 
 from their honoured ranks many celebrated naturalists 
 arose. Even to glance at the whole history of the 
 sciences would take up volumes. Permit me, however, 
 just to remark the presence of a controlling Power in 
 the manner in which their present position has been 
 attained. In these days what could we do with the 
 old system of navigation? What astrology would 
 have made of the numerous planets and planetoids, 
 which the telescope has discovered, I cannot say ; but 
 at any rate, it is evident that to restore even the old 
 theories of astronomy would be to annihilate commerce. 
 And supposing that discoveries had kept thronging 
 upon us in chemistry, without a knowledge of their 
 relations, it is hard to tell whether it would have 
 happened for our good or harm. And, further, with- 
 out the systems of natural history, the Fauna and 
 Flora of so many discovered lands would have served 
 only to swamp our knowledge. 
 
 In all these discoveries, as well as in numerous 
 others, we are but ' following the indications of true 
 
78 POPULAR GEOLOGY. 
 
 philosophy when we say that Divine wisdom has ad- 
 apted them to the requirements of the times, and that 
 men were raised up, from time to time, whose minds 
 were most fitted for the work they had to do, and the 
 difficulties they had to encounter. This law of adap- 
 tation in modern times, in God's providential govern- 
 ment, is but analogous to His proceedings in ages long 
 anterior to the present. 
 
 The unravelling of the gordian knot of difficulties, 
 which has entangled every science, has been achieved 
 solely by following the promptings of nature ; even 
 when they have been contrary to received opinions ; 
 and the more this simple plan has been adhered to, 
 the more successful have its students been. 
 
 Of all the sciences, perhaps, geology is the youngest, 
 and yet Sir John Herschel has declared that in the 
 scale " it stands next to astronomy." The reason of 
 its rapid progression has been the high state of culti- 
 vation which many kindred sciences obtained; and 
 the multiplied means of observation and research. 
 Although geology has fallen upon these latter days, 
 yet it has not attained its present dignity and au- 
 thority at once. Let me, before I exhibit to you the 
 outlines of the science, its classification, &c., briefly 
 dwell upon its history. 
 
 Those of you who live in districts where the rocks 
 contain fossils, will remember the' stones which are 
 connected with them. So far from having passed un- 
 noticed, the inhabitants have seen that, as they were 
 there, they must have been formed by some means, 
 
POPULAR GEOLOGY. 79 
 
 and so have set their wits to work to account for their 
 presence. Hence we have the numerous explanations 
 and legends so common in fossiliferous districts. In 
 Derbyshire all the fossils are ascribed to the agency of 
 Noah's flood ; an agent, by the way, which has been 
 very handy to cosmogonists from time immemorial. 
 This agency is all-powerful at present with the unedu- 
 cated classes, and even with some who profess to be 
 educated, in accounting for the presence of fossiliferous 
 rocks, to whatever formation they may belong. I 
 remember once being in the neighbourhood of Matlock, 
 exploring its interesting caverns, when the guide un- 
 dertook to explain how the rocks had " biled up " at 
 the time of the Flood, and how all the organic remains 
 had been entombed. He took care, however, to stand 
 up for the originality of his views, and declared him- 
 self quite innocent of ever having studied books. 
 
 In the Lias deposits of Yorkshire, ancient legend 
 accounts for the presence of the numerous snake-looking 
 marine shells, by asserting that they once were real 
 snakes, which infested the neighbourhood to such a 
 degree that the prayers of a pious nun were interested, 
 first in decapitating them and afterwards in changing 
 them into stone. Sir Walter Scott has introduced 
 this legend in his " Marmion." 
 
 " And how the nuns of Whitby told, 
 How of countless snakes, each one 
 Was changed into a coil of stone 
 When holy Hilda prayed. 
 Themselves, within their sacred bound, 
 Their stony folds had often found." 
 
80 POPULAR GEOLOGY. 
 
 The numerous joints of encrinital stems and fingers, 
 which occur in the same rocks, are accounted for by 
 legend, and is now enshrined in our literature by the 
 pen of Scott. 
 
 "Nor did Sir Cuthbert's daughters fail 
 To vie with them in holy tale. 
 
 ft ''*'** 
 
 On a rock of Lindisfarne 
 
 St. Cuthbert sits, and toils to frame 
 
 The sea-born beads that bear his name." 
 
 Many of the fossil-dealers turn the snake-legend to 
 account, for if a visitor asks to see some of these fossil 
 snakes, the dealer not unfrequently asks if he wants 
 them with the head, or without the deficiency being 
 readily supplied by a little manual labour and a small 
 file. The Belemnites, which are found in the rocks of 
 three succeeding formations, are, in some places, sup- 
 posed to be " thunderbolts ; " and, in some parts of 
 Scotland, are reckoned as antidotes to witchcraft. In 
 Spain, as lately as 1835, a species of shell which 
 abounds in the older rocks, and which goes by the 
 name of Terebratula, ivas carried by the inhabitants 
 as a charm against the attacks of cholera ! In our 
 own chalk districts, the glossy teeth of fishes which 
 are found, go by the name of " petrified tongues." 
 But of all the queer explanations rendered, that of the 
 Maltese is the queerest. The fishes' teeth, in their 
 island, have a more infernal origin assigned to them, 
 for they go by the name of " Satan's claws," it being 
 
POPULAR GEOLOGY. 81 
 
 stated that that personage has had them torn off, 
 whilst attempting to climb the cliffs. 
 
 The occurrence of fossil shells in the mountains of 
 Egypt, is remarked by Herodotus ; and Xenophanes, 
 who lived five hundred and thirty-five years before 
 Christ, argued for the antiquity of the earth, and the 
 vital origin of its contained fossils. Aiistotie, the 
 father of natural history, taught geological doctrines, 
 such as the filling up of rivers, formation of deltas, 
 and volcanic upheavals. Strabo the geographer dis- 
 cusses at some length the occurrence of fossil shells at 
 great elevations, and remote distances from the sea, 
 and cites the opinion of another philosopher that they 
 had been left by the retiring of the seas, in the same 
 way that lakes and rivers were drained in Egypt. Ovid, 
 in his " Metamorphoses," gives some remarkably sound 
 geological facts, which prove him to have been a man 
 of great observation. Fossiliferous rocks did not escape 
 the notice of the Christian fathers, for we find Ter- 
 tullian and St. Augustine adducing them in proof of 
 the Noachian deluge. 
 
 In the middle ages, the presence of organic remains 
 was attributed to the influence of the stars ; and many 
 of them were employed in the necromancer's art. This 
 opinion prevailed for some time, in opposition to that 
 of the deluge. Leonardo da Vinci, the artist, philo- 
 sopher, and engineer, wrote a tract in refutation of this 
 fantastical theory. Afterwards, we find Gessner, of 
 Zurich, already celebrated as a naturalist, devoting 
 himself assiduously to the study of minerals and fos 
 
 G 
 
82 POPULAR GEOLOGY. 
 
 sils ; he afterwards wrote a work upon this subject, 
 hut he did not commit himself to any theory in it as 
 to whether fossils were once living creatures or not. 
 Palissy the potter, who lived in the sixteenth century, 
 stoutly maintained that fossils were the remains of 
 marine animals \ and, further, he argued from the 
 state of perfection in which they were found, that they 
 could not have been carried from a distance, but must 
 have lived in the localities where they are found en- 
 tombed. Towards the close of the sixteenth century, 
 natural history began to nourish in Italy. It was 
 patronized by the reigning pontiff, and a collection 
 was formed in the Vatican, which soon rose to be the 
 finest in Europe. "We also read of Steno, a native of 
 Copenhagen, prosecuting the study ; and, during his 
 residence in Italy, discovering the fossil bones of the 
 Val d'Arno, He taught that both the fossil shells 
 and plants had a vital origin. In 1690, almost for the 
 first time, we find a naturalist, Quirini, in a work on 
 fossil shells, maintaining that they could not have 
 originated with the Noachian deluge. It was about 
 this time, too, that Leibnitz published his views con- 
 cerning the igneous fusion of the earth, and its subse- 
 quent cooling ; and his contemporary, Dr. Hooke, in 
 England, enunciated his belief in the organic nature 
 of fossils, and pointed out their tropical character. 
 He also showed the effects of volcanic action, the 
 elevation and depression of land, and several other 
 subjects which hitherto had almost escaped attention. 
 Eay, whose writings made natural history attractive, 
 
POPULAR GEOLOGY. 83 
 
 and disarmed much of the opposition from theology, 
 was fully persuaded of the organic origin of fossil 
 remains ; and Dr. Woodward, who had been an ardent 
 naturalist, materially aided the science which was now 
 rapidly forcing itself into notice, by bequeathing his 
 collection of minerals and fossils to the University 
 of Cambridge, and endowing a professorship of the 
 science. 
 
 In looking back upon the history of any science, 
 we can scarcely suppress a smile when we see the 
 foolish views which its students once held ; just as a 
 man who has attained some experience of life, smiles 
 at the follies of his childhood and youth. Linnaeus, 
 who had done so much for botany, by his artificial 
 classification, carried his theory of sexual distinction 
 into the mineral kingdom, and so classed them all, either 
 as male or female. The fame which this celebrated 
 naturalist achieved did much to render all the natural 
 sciences popular. In France, Buffon threw a charm 
 over these subjects by his fascinating style, and also 
 by the peculiar views which he propounded. In a 
 work which he published, called " Epochs of Na- 
 ture," he graphically describes the changes which 
 have taken place on our earth during the periods of 
 the past. 
 
 About the middle of the last century, a Prussian 
 mineralogist and chemist, named Lehmann, who had 
 devoted much attention to rocks, published a work 
 in which he arranged them under three great 
 divisions primitive, secondary, and tertiary. The 
 
 G2 
 
84 POPULAR GEOLOGY. 
 
 primitive rocks comprised all the so-called metamor- 
 phic ones ; the secondary included all the fossiliferous ; 
 and the tertiary the residuary beds, such as clays, 
 gravels, sands, &c. Lehmann's classification of three 
 great divisions has been retained, although it has been 
 greatly modified. Soon after this, Freyburg, in Saxony, 
 became famous for the numerous students which ad- 
 journed thither from every country in Europe. Werner, 
 the great mineralogist, was teaching his popular doc- 
 trines respecting the origin of minerals and rocks. He 
 followed, more or less, the arrangement of Lehmann, 
 but grouped large masses of rock under the indefinite 
 name of " transition " strata. He also taught that all 
 rocks were of aqueous origin, and completely denied 
 the agency of any igneous force whatsoever. These 
 extreme dogmas, as a matter of course, excited a spirit 
 of opposition in those who taught the contrary, and 
 the 'issue was a fierce war of debate, which separated 
 them into the Neptunian and Plutonic schools, so 
 called from the extreme opinions which they held con- 
 cerning the agencies of fire and water. For years this 
 conflict raged, which not only did much harm to 
 geology, but also withheld that calm spirit of research 
 which is so necessary to the progress of any science, 
 and fostered a spirit of disgust and ridicule in the 
 minds of lookers-on. 
 
 Hutton, at the head of the Plutonists, maintained 
 that granite, trap, basalt, &c., were of igneous origin 
 that granite was matter which had been fused under 
 immense pressure, so that the possibility of its gaseous 
 
POPULAR GEOLOGY. 85 
 
 parts escaping had been entirely precluded. Many o"f 
 Dr. Button's views are now held by geologists, although 
 others of them have been much modified. 
 
 But while the scientific world was divided by the 
 dissensions of Werner and Hutton, a single individual, 
 with unwearied perseverance, was quietly mapping 
 and laying down the order of succession in which 
 British rocks occur. He had, also, discovered the im- 
 portant fact that the different strata might be known 
 by their imbedded fossils. In 1790 he published his 
 " Tabular view of British strata;" and, in 1815, the 
 results of his mapping labours. D'Aubuisson, a dis- 
 tinguished pupil of Werner, acknowledged the suc- 
 cess of Smith's labours, and remarked that "what 
 many mineralogists had only accomplished for a 
 small part of Germany, during half a century, had 
 been effected by a single individual for the whole of 
 England." 
 
 Soon after this, geological societies were formed. 
 That of London was established in 1807. Knowing, 
 from experience, the ill effects which a rash theorizing 
 had had upon the science, the members resolved that 
 they would refrain from such a course for a time, and 
 proposed for their present object the " multiplying and 
 recording of observations, patiently deferring the 
 result to some future period." It is, doubtless, this 
 wise resolution, more than anything else, which has 
 cleared the science from error, and rendered it, as it 
 well deserves to be, one of the most attractive studies 
 on the roll of human knowledge. 
 
86 POPULAE GEOLOGY. 
 
 Since the formation of the London Society, similar 
 ones have sprung up in the various capitals and towns 
 of Europe, and in America ; each of which has served 
 as a centre from which numerous observers have sallied 
 forth to collect observations, and study their peculiar 
 localities. A great work had to be done. For a long 
 time the Old Eed Sandstone was classed with the coal- 
 measures ; and the Silurian limestones and shales 
 were known as transition rocks. Even long after these 
 beds had been disassociated, the magnesian limestone 
 was accounted a member of the New Red Sandstone 
 system ; and the beds of clay, gravel, and sand, now 
 known as the drift deposits, were then termed " dilu- 
 vian," and were ascribed by some of the leading geolo- 
 gists to the Noachian deluge. Since then, these deposits 
 have been found to contain their peculiar fauna, just 
 as any other deposits have theirs. Many a year of 
 patient observation and toil has been spent in unravel- 
 ling these difficult subjects. The spirit in which they 
 have been pursued has been no dogmatic one. Many 
 a fair theory has been overturned by a few simple facts, 
 and the founder himself has been one of the first to 
 decry his previous opinions. 
 
 It is interesting to observe the influence which 
 master-minds have had upon the science. Above thirty 
 years ago, Sir Roderick Murchison began the study of 
 the bottom rocks, including the carboniferous down- 
 wards. For that purpose he applied himself to the 
 observation of a locality in which these various forma- 
 tions were supposed to be developed. Everyone has 
 
POPULAR GEOLOGY. 87 
 
 heard of the results of his labours, and how the locality 
 has given the name to one of the most interesting of 
 the geological formations; thus " Siluria " will exist as 
 long as our language endures a monument of perse- 
 verance and industry ! Shortly after, Sir Charles Lyell 
 applied himself to the other end of the geological 
 scale, and worked out the various subdivisions of the 
 tertiary formation, classifying them by the per-centage 
 of existing species of shells which the different beds 
 contained. In like manner, the name of Mantell has 
 become necessarily connected with the Wealden, and 
 that of Hugh Miller with the Old Eed Sandstone ; 
 whilst Dr. Buckland did good service in the Oolite, 
 and threw a fascination over the whole study by the 
 publication of his Bridgewater treatise. We find, also, 
 the name of Professor Phillips connected with our 
 English mountain limestone ; and that of Professor 
 Sedgwick with the Cambrian formation. On the 
 Continent, especially in France, Brogniart gave his 
 attention to the study of fossil botany, and D'Orbigny 
 studied the fossil shells of the Oolite, and gave the 
 results to the world in magnificently-illustrated vol- 
 umes. Previous to this, Cuvier had made the " dry- 
 bones " of the Paris basin to " live again " by his know- 
 ledge of comparative anatomy. There is also a host 
 of honoured names who have faithfully and diligently 
 worked as associates. Elie de Beaumont, Saussure, 
 Dolomieu, Koninck, and others, who have so connected 
 themselves with the progress of geology, that its his- 
 tory cannot be given without mentioning them. 
 
88 
 
 POPULAR GEOLOGY. 
 
 The sketch which I have given of the progress of 
 geological science, leads me to consider the prevailing 
 system of classification ; and, in doing so I shall follow 
 the arrangement given by Sir Charles Lyell, which is 
 that commonly followed by geological writers of the 
 present day : 
 
 1. Recent 
 
 (Post-Tertiary. 
 
 3. Newer Pliocene \ 
 
 ' Pliocene. 
 
 4. Older 
 
 5. Upper Miocene 
 
 Miocene. 
 
 6. Lower 
 
 7. Upper Eocene 
 
 76. Middle Eocene. 
 
 8. Lower... 
 
 1 
 
 I 
 
POPULAR GEOLOGY. 
 
 9. Maestricht beds 
 
 1 0. Upper white chalk 
 
 11. Lower 
 
 1 2. Upper green-sand 
 
 13. Gault 
 
 1 4. Lower green-sand 
 
 15. Wealden 
 
 16. Purbeck beds v 
 
 17. Portland stone I 
 
 1 8. Kimmeridge clay 
 
 19. Coral rag 
 
 V Oolitic, or Juras- 
 
 20. Oxford clay sic. 
 
 21. Great, or Bath Oolite. 
 
 22. Inferior Oolite 
 
 23. Lias , 
 
 24. Upper Trias \ 
 
 25. Middle Trias, or Mus- i 
 
 Trias, or New Eed 
 chelkalk Sandstone. 
 
 26. Lower Trias . 
 
 J 
 
 89 
 
90 POPULAR GEOLOGY. 
 
 27. Permian, or Magnesian | 
 
 V Permian. 
 
 limestone j 
 
 28. Coal measures ) 
 
 V Carboniferous. 
 
 29. Carboniferous limestone j 
 
 30. Upper Devonian ) Devonian, or Old 
 
 I Red Sandstone. 
 
 31. Lower J 
 
 32. Upper Silurian \ 
 
 C Silurian. 
 
 33. Lower J 
 
 34. Upper Cambrian \ 
 
 V Cambrian. 
 
 35. Lower I 
 
 36. Upper Laurentian 
 
 37. Lower 
 
 cS 
 
 J 
 
 It will be seen from the foregoing diagram of strata 
 that a " formation " consists of several strata of rock, 
 each of which often possesses a characteristic name. 
 A stratum is a bed, or a series of beds, which can be 
 detected in other localities, and its true place assigned 
 to it in the geological scale. 
 
 I have been speaking all this time about rocks, and 
 
POPULAR GEOLOGY. 91 
 
 yet I have not defined what a rock is ! This state- 
 ment may excite a smile among those who have been 
 in the habit of associating the idea of rock with any- 
 thing of a stony nature. In some botanical treatises 
 we find the authors laying down the character of a 
 plant ; or, rather, defining what a plant is. But so 
 faint is the line of distinction between the lower 
 orders of the animal and vegetable kingdoms, that 
 some botanists boldly aver that they cannot define the 
 true character of a plant. The geologist, however, 
 has taken the matter of definition into his own hands, 
 and so, in order to bring all the layers which compose 
 the earth's stratified crust under his observation, he 
 calls every bed, whether sandstone, limestone, shale, 
 sand, or clay, a " rock." This term, therefore, will not 
 be difficult for you to remember. 
 
 Taking all the rocks together, as they are found 
 scattered over the surface of the globe, we may separate 
 them, first, into two great classes : viz., those which 
 have been formed by the agency of intense heat, such 
 as the granites, traps, and the lavas which flow from 
 modern volcanoes ; and those which have been formed 
 by the agency of water, such as limestones, sandstones, 
 gravels, sands, and clays. These two great classes of 
 rocks, are termed respectively, the igneous and the 
 aqueous. Strange to say, and yet not more strange 
 than true, every one of the latter class of rocks has 
 been formed along the bottoms of seas, rivers, or lakes, 
 which have long since flowed off, upon their upheaval, 
 into the lowest levels. We may, therefore, however igno- 
 
92 POPULAR GEOLOGY. 
 
 rant of geological facts, safely infer, wherever we see such 
 rocks, that the sea has been repeatedly in that neigh- 
 bourhood, and that the rocks in question were deposited 
 along its bottom. Now many of the creatures, which 
 lived in the waters of these seas, when they died fell 
 to the bottom, and became enveloped in the muddy 
 sediments which were there accumulating ; so that, 
 when the sea-bed became uplifted, and the muddy 
 sediments of its bottom hardened into stone, these 
 creatures, whether fishes, corals, or shells became 
 hardened, and turned into stone along with it. It is 
 from a knowledge of these fossil remains, and by com- 
 paring them with creatures now existing, that we 
 arrive at the conclusion that they are quite distinct 
 from any now living, and, consequently, that when 
 they lived they were suited to the diiferent circum- 
 stances which then prevailed. 
 
 Now just as every bed, or stratum, in geology, is 
 called a " rock," so all the organic remains which are 
 found imbedded in them are called " fossils." Their 
 appearance does not at all derogate from this appella- 
 tion ; for we may find fossil shells and corals as 
 perfect as those existing in the present seas ; and 
 bones, none the heavier for their long entombment, 
 presenting all the appearances of bones which have 
 been buried for only a few years. Again, fishes' teeth 
 may be obtained from the carboniferous shales, the 
 gault, and the chalk, as entire in their form, as sharp 
 along their edges, and as glossy with enamel as those 
 obtained from fishes of a similar class which are living 
 
POPULAR GEOLOGY. 93 
 
 now. The appearance of fossil shells is not an indica- 
 tion of their antiquity. Strophomenae may be dis- 
 interred from the Wenlock shales, of the Silurian 
 formation, glistening with iridiscent nacre, like the 
 interior of the pearl-mussel ; and producta, pecten, 
 and terebratula are to be obtained from the carboni- 
 ferous limestone, still retaining their colour-bands. 
 On the other hand, in strata of far more modern date, 
 we find the fossils completely transmuted into stone, 
 like those found in the Portland oolite, where we only 
 find the casts of the fossils, the original shells having 
 been decomposed, and the hollows left by them in the 
 rocks filled up with adventitious matter, still, however, 
 retaining the markings of the original fossils. Bones 
 of reptiles from the Wealden beds are sometimes found 
 as porous as those found in caverns ; and fossils from 
 the newest beds of the tertiary are often older in their 
 appearance than those of the Cambrian rocks. 
 
 The maximum thickness of the sedimentary, or 
 aqueous rocks in Great Britain, as ascertained by 
 Professor Ramsey, is as follows : 
 
 Feet. 
 
 Palaeozoic 57,154 
 
 Secondary 13,190 
 
 Tertiary 2,240 
 
 Total . . . 72,584 
 
 This enormous thickness, of above thirteen miles, 
 has been formed, as I before said, by the same slow 
 
94 POPULAR GEOLOGY. 
 
 processes which we know are at present forming rocks. 
 Consequently, one of the great facts which the slightest 
 knowledge of geology will show, is the vast periods of 
 time which have been taken up in their elaboration. 
 The sediments which are carried down and deposited 
 by the Mississippi at present, are at the rate of 600 feet 
 in 100,000 years, so that, at this rate, it would take 
 upwards of twelve millions of years to form the 
 deposits I have mentioned. You must not suppose, 
 however, that I mean to state that this is the regular 
 rate in which sediments have always been laid down. 
 In some of the rocks we can tell that the deposits were 
 formed far more rapidly than others, as, for instance, 
 the various conglomerates, and coarse-grained sand- 
 stones ; but, I mentioned the fact concerning the 
 Mississippi sediments, to show you a glimpse of the 
 past eternity which has been occupied in forming the 
 stony layers of the earth's crust. 
 
 There are, also, other means by which we may see 
 the great periods of time which tjie formation of the 
 stratified rocks have occupied. Thus, we find fossil 
 trees, buried in the oolites, which, we can tell from 
 their rings of annual growth, lived a hundred years or 
 more upon the dry land, before they were swept down 
 by rivers into the sea, and entombed in the mud along 
 its bottom. In some shelly strata we find individuals 
 of a species of shells, in every stage of their growth, 
 from the young to the adult ; and yet in a single layer 
 of such rock, sometimes not above a foot in thickness, 
 this species dies out, and is not found afterwards, 
 
POPULAR GEOLOGY. 95 
 
 thus plainly showing that in the forming of the bed, 
 such long ages were taken up as allowed a whole 
 species of shell to be created and pass, like an indi- 
 .vidual, through the various stages of its existence, until 
 extinction put an end to its specific life ! Further, it is 
 not uncommon to find in such layers proofs of what 
 you will allow me to call the instincts which these 
 extinct creatures possessed. Thus, the geologist often 
 finds shells which had become broken or damaged 
 during the lifetime of their inhabitants, and which were 
 afterwards repaired by fresh layers of shelly matter. 
 Fossil saurians have been found containing in their 
 stomachs remains of the creatures upon which they 
 preyed : and even the fossil dung of both fishes and 
 reptiles, which commonly go by the name of coprolites, 
 is commonly found charged with the comminuted 
 scales and bones of the creatures upon which they 
 preyed. Among the fossil ferns of the coal-measures, 
 some are found with the round spore-cases on their 
 backs, just as we see them on the backs of the fronds 
 of the common wall-polypody. Nay, every indication 
 of the common processes of nature, which can show 
 us the slow growth of these formations, is met with in 
 them. Even the foot-prints of animals as they walked 
 on the old sea-beaches, the impression of rain-drops left 
 by them when they fell, the tracks and borings of 
 marine worms on the sandy shores, are all preserved 
 in the rocks, locked up in unmistakable language ! 
 Could we wish for more minute, or more certain proofs of 
 the habitation of our world before man became its lord 1 
 
96 POPULAR GEOLOGY. 
 
 There are, also, in the same deposits, as those I have 
 just mentioned, evidences of the changes which must 
 have taken place, both in the direction of the sea- 
 currents and the materials which they brought. Thus 
 we sometimes find fine shales resting directly upon 
 limestones ; limestones intercalated with sandstones ; 
 and sandstones passing gradually into conglomerates. 
 The waters which brought down these various materials 
 must have changed their directions some scores of 
 times ; and yet, thousands of years may have in some 
 cases must have elapsed during the formation of a 
 single deposit ! So that currents now existing in the 
 sea, which we know have been flowing in one direc- 
 tion ever since the historic period, do not fully repre- 
 sent the duration of those that brought down the 
 various materials which have composed the thousands 
 of different beds which, together, make up the whole 
 of the stratified rocks. 
 
 You will have perceived from the scale of stratified 
 rocks which I have given you, that many of the names 
 prefixed to the formations are local. This arose, in 
 many instances, from the local peculiarities of the 
 rocks in the district where they were first studied. 
 Thus, the Cambrian rocks were so named by Professor 
 Sedgwick from their being developed in Wales. The 
 Silurian was so called by Sir R Murchison from that 
 series being studied and grouped' in the county of the 
 ancient British tribe of Silures. The Devonian \vas 
 first studied in Devon and Cornwall, and was so 
 named from that circumstance, whilst its other name 
 
POPULAR GEOLOGY. 97 
 
 of " Old Red Sandstone " was given to it to distinguish 
 this formation from the New Red Sandstone which over- 
 lies the coal measures, and, also, on account of the 
 prevailing colour of the sandstones and conglomerates 
 which make up the deposit. As every one knows, 
 the carboniferous formation, or coal measures, takes 
 its name from its coal-bearing peculiarities ; whilst the 
 Permian formation, which was formerly divided 
 between the New Red Sandstone and the coal measures, 
 owes its name to Sir R. Murchison from his finding it 
 so largely developed in the Russian province of Perm. 
 You will perceive that I am but glancing at the 
 general features which have originated these various 
 names ; it requires an intimate knowledge with geolo- 
 gical literature to make the student acquainted with all 
 the terms employed by English and foreign geologists. 
 The Triassic, or New Red Sandstone, is so named, in 
 the one instance, from the three great divisions of 
 Bunter-candstein, Muschelkalk, and Keuper, into 
 which it is split ; and, in the other, in order to dis- 
 tinguish its age from the Old Red Sandstone which 
 underlies the coal measures. The term oolite, now 
 adopted by almost all geologists, was so called at first 
 from the roe-like appearances which some of its lime- 
 stones presented, but this formation, among continental 
 geologists, generally goes by the name of Jurassic ; its 
 different subdivisions, also, have been named from the 
 localities where they were first studied. Most of the 
 terms employed in the classification of the cretaceous, 
 or chalk deposits, are as arbitrary as the rest. The 
 
 H 
 
98 POPULAR GEOLOGY. 
 
 Maestricht beds from the place where they are deve- 
 loped, and the remaining from their mineral peculiari- 
 ties. But, above all the rest, the divisions of the 
 tertiary beds are based upon the most scientific data, 
 as I before said; the data being the proportion of 
 recent species of shells which the various beds present ; 
 the whole of the beds being, in this manner, grouped 
 under four divisions, Eocene, Miocene, Pliocene, and 
 Pleistocene. 
 
 But, while a great deal of attention has been paid to 
 the different formations, we must not fall into the 
 common error of supposing each to be distinct, that is, 
 of supposing each formation to be the life-time, if I 
 may so call it, of a single creation. It was formerly 
 supposed that each formation was distinct in its upper 
 and lower horizons, from the over and underlying rocks. 
 But as geological discovery gains ground, " the diffi- 
 culty of assigning clear lines of separation must 
 unavoidably increase in proportion as chasms in the 
 past history of the globe are filled up." So that, with 
 each advancing step in geological science it becomes 
 more and more difficult t9 draw precise limits between 
 successive formations. 
 
 The fossil remains of each period, although suffi- 
 ciently distinctive, are not always limited to one 
 formation, that is, at the end of each period there 
 was not a total destruction of either the animal or 
 vegetable forms, but, in this respect, one forma- 
 tion dovetailed, so as to speak, into another. When 
 the changing circumstances of one period caused a 
 
POPULAR GEOLOGY. 99 
 
 certain class of animals to pass into extinction, 
 another, and often a nearly allied class, was called into 
 existence to supply its place. From what we can 
 learn of the habits of these new creations they seem 
 to be more adapted to the changed circumstances, than 
 the extinct race could have been. Species of fossils 
 are sometimes introduced and become extinct in one 
 formation, and Darwin assigns about three such new 
 species, on an average, to each geological period. 
 Other types of fossils are more long-lived ; some genera 
 are found which came into existence with the earliest 
 fossiliferous rocks, and are living in the seas of the 
 present day, such as the nautilus and terebratula 
 family. In fact, the different families and genera of 
 fossil shells seem to have had a limited duration, just 
 as different individuals have now, Hence we find 
 such families extending from the period of their 
 creation into maturity, and afterward as gently 
 graduating into extinction. This life-time of genera 
 does not seem to have been equally long ; just as, at 
 present, some men are old at forty, whilst others are 
 comparatively young at fifty so do we find groups of 
 fossil shells extending through the several stages of 
 their generic life into different periods of time. Thus, 
 the orthoceratite family, Avhich came into existence in 
 the Silurian period graduates through the Devonian 
 and reaches its maximum of existence during the 
 Carboniferous epoch, afterwards it wanes through the 
 Permian and New Eed Sandstone and passes into ex- 
 tinction in the times of the Oolite. Eut we find the 
 
 H 2 
 
100 POPULAR GEOLOGY. 
 
 rhynconella family reaching its maximum of existence 
 in far later times, although created during the same 
 epoch as the orthoceras, for various species of rhyn- 
 conella are living in the seas of the present day, 
 although the genus is evidently passing into extinction. 
 The same fact may be observed in numerous other 
 groups of fossil shells, such as ammonites, gryphites, 
 trigonia, &c. As a general rule it may be expressed 
 that those creatures which are the most highly organized 
 have had the shortest duration ; although for that 
 reason they best mark the different periods when they 
 lived ; while those which are more lowly organized have 
 the most extended range, in point both of time and 
 space. So that in the animal world we feel ourselves 
 able to apply the fable of the oak and the reed. 
 Changing circumstances have swept into extinction 
 the highly organized races, whilst they have passed 
 harmlessly over the more hardy and less highly 
 endowed. Hence, while various families of fishes and 
 reptiles have been brought upon the stage of existence 
 since the times of the Silurian, and have again passed 
 away, the lowest forms of life, such as the zoophytes, 
 which were luxuriant in the early Silurian seas, 
 have lived in the waters of every succeeding epoch 
 until our own day, when their numbers forbid us to 
 suppose that the race has suffered anything in point of 
 vigour. 
 
 The old adage " Natura non facit saltum" " Nature 
 never makes a leap," is every day proving true in 
 geology. The convulsions which were formerly sup- 
 
POPULAR GEOLOGY. 101 
 
 posed to mark the close of each period, are now proved 
 to be, in many cases, only local ; and, it is probable, 
 that, when fresh localities have been studied, there 
 will be found from the lowest Laurentian to the pleis- 
 tocene, a gradual passing of formation into formation ; 
 so that the whole group of aqueous rocks will have to 
 be looked upon as one grand group, accumulated in 
 various parts of the earth, and at different times ; and 
 like a graduated scale this -entire formation will mark 
 the various changes through which our old planet has 
 passed, and the successive creations of animal and 
 vegetable forms which peopled it ! 
 
 There are, however, two great breaks in the chain of 
 life which seem to be natural ones. I allude to that 
 which took place at the end of the Permian period, 
 and which separates the paleozoic from the secondary 
 division ; and, also, that which took place at the close 
 of the chalk formation, and which further separated 
 the secondary from tertiary times. The permian 
 rocks are found graduating into the trias, in many 
 places without any dislocation occurring between the 
 two formations, while the change in animal life is 
 quite distinct. The same occurs with regard to the 
 chalk and tertiary formations, with this difference, 
 that here the two classes of rocks are often found un- 
 conformable. When this fact was first pointed out, 
 it was stated that the break in palaeozoic life occurring 
 at the close of the permian was entire, and that not a 
 single type passed thence into the secondary. In like 
 manner the same was said with regard to thetertiary 
 
102 POPULAR GEOLOGY. 
 
 and chalk. But since then, several localities have 
 come to the light where fossils of a decidedly palaeo- 
 zoic type are found mixed with secondary forms, as, 
 for instance, the St. Hallstadt beds, where orthocrata 
 are found mixed with ammonites and belemnites, and 
 where the ground is so debateable from this circum- 
 stance that one class of geologists has assigned the 
 place of the beds to the coal measures, whilst another 
 ranks it as belonging to the oolite. Again, with 
 regard to the next break in organic life ; at Maas- 
 tricht, in Holland, and also at Saxoe, in Denmark, 
 there occur beds which seem to be intermediate with 
 the latest chalk and the oldest tertiary. Here are 
 found associated true chalk fossils, such as the pecten 
 quadricostatus, the " four-ribbed pecten," along with 
 genera only found elsewhere in the tertiary beds, such 
 as oliva, voluta, fyc. 
 
 It is facts such as these which lead u's to reason, a 
 priori, that there only requires extended areas of 
 investigation, and patient observance to adduce other 
 and similar ones. Mr. Hamilton in his presidential 
 address to the Geological Society, 1854, remarked that 
 "we shall find that there exists a gradual passage from 
 the very oldest to the newest strata, that from the 
 earliest fossiliferous rooks to the most recent post- 
 pliocene formations, there has been one unbroken 
 sequence of deposits, modified only by local disturb- 
 ances, showing the gradual change of organic life 
 according to the different conditions of existence ; and 
 that in every case a certain number of species existing 
 
POPULAR GEOLOGY. 103 
 
 in the beds below have been continued upwards, and 
 mingled with new forms specially created to suit the 
 new state of things." 
 
 But this fact, nevertheless, does not in the least 
 detract from the fact, that one epoch was the age of 
 fishes, another of reptiles, and another of mammals. 
 On the contrary, we may speak of each as peculiar, 
 only remembering the relation which it holds in the 
 geological scale. Neither does this fact at all interfere 
 with the succession of the fossiliferous rocks, or with 
 their peculiarities ; while, on the other hand it relieves 
 the geologist of a great amount of perplexity, and 
 serves to disencumber the classification of the burden 
 of a heavy and increasing nomenclature. In speaking 
 of various rocks, such as Devonian, Liassic, and others, 
 which occur in widely-circulated areas, the geologist 
 does not always mean that they were deposited con- 
 temporaneously ; he can only approximate their age by 
 their imbedded fossil remains. 
 
 Before palaeontology became a science, the mineral 
 character of a rock was the only index that was fol- 
 lowed in identifying it. It was this method of 
 identification which served as a bone of contention to 
 the Plutonists and Neptunians. But it is now estab- 
 lished as one of the commonest geological facts, that 
 the mineralogical structure and appearance of a class of 
 rocks, are not necessary, or even common, accompani- 
 ments. Many of the names of colour which are pre- 
 fixed to beds were given to them from the appearance 
 which they presented in the first observations, and 
 
104 POPULAR GEOLOGY. 
 
 have been retained since from motives of convenience. 
 Thus, red sandstone is not a necessary accompaniment 
 to either of the formations which bears that name, for 
 there are found interstratified with them, beds, both of 
 light-coloured sandstone and limestone. Neither is 
 the red colour peculiar to them, for it is seen in rocks 
 of the Permian and carboniferous formation, and also 
 in those of the Tertiary period. The carboniferous 
 limestone, which, in England is partly of a crystalline 
 structure, in Eussia, passes into a kind of chalk. And 
 the oolitic appearance of the limestones in the rocks of 
 that age is not peculiar to them, for this appearance is 
 presented both in the carboniferous, and also in much 
 later formations. The chalk and greensand beds, also, 
 have in their appearance much in common with other 
 rocks ; and, in America, some of the cretaceous, or 
 chalk beds, resemble the lias more than any other ; 
 and in Texas, the chalk beds exist as indurated sili- 
 ceous limestones, containing similar fossils to those 
 found in beds of the same age in England. The 
 tertiary limestones of Australia are sometimes found 
 presenting -all the appearances of friable chalk ; whilst 
 in deposits of the same age along the Alps there are 
 found beds of true mica-schist, the result of metam- 
 orphic action. The colour of the different rocks 
 would depend, in many instances, upon the original 
 rocks from which they were derived by the slow 
 processes of denudation. Thus, those seas which 
 washed the shores of crystalline rocks, such as mica- 
 schist and gneiss, would deposit red sand or mud, 
 
POPULAR GEOLOGY. 105 
 
 which, of course, would subsequently harden into 
 rock. 
 
 You see, therefore, that the mineralogical struc- 
 ture, or colour of any rock cannot be depended upon 
 either as a criterion, or as a means of identification ; they 
 may, under some circumstances, assist in filling up 
 data for comparison, but they will never serve as in- 
 fallible guides alone. 
 
 " What then," you will ask, " are the means em- 
 ployed in arriving at the knowledge of the different 
 rocks, or how may we detect rocks of one formation 
 from those of another?" This question is a perfectly 
 natural one, and of the highest importance, inasmuch 
 as upon its truthful answer there depends the most 
 valuable results. And yet, I know of but <_ ne answer to the 
 question, viz. : by their organic remains, and relative 
 position. Simple as this answer may appear, it is never- 
 theless a positive fact that the various rocfts may be 
 known from their imbedded fossil remains. It is upon 
 this fact that the classification of geology is based ; 
 and all will perceive the wide and important field 
 which opens out before us as the result. Transport a 
 geologist anywhere, and place him, hammer in hand, 
 before a class of rocks he never saw or heard of before, 
 and he will tell, from the fossils he chips out, the 
 relative age and position of the rocks in question. 
 ^Nay, we may even state it as a rule, that the different 
 rocks yield their characteristic fossils almost as truly as 
 different trees bear their peculiar kinds of fruit. A 
 botanist would never expect, from any freak of nature, 
 
106 POPULAR GEOLOGY. 
 
 to find figs growing upon thistles, or grapes upen the 
 bramble ; just as soon, however, would a geologist 
 think of finding trilobites in the oolitic formation, or 
 ammonites in the Silurian. 
 
 In giving this statement, however, I do not wish 
 you to understand that the life of each period was 
 general in its character, and not influenced by geo- 
 graphical distribution as the races' are now. On the 
 contrary, ever since life began to be, it has been in- 
 fluenced by local phenomena. "What I wish you to 
 understand is, that the fades, or the general appear- 
 ance of the fossils of each formation is peculiar to it. 
 I remember the first time I travelled by the Great 
 ^Northern Railway, from London to Manchester, that 
 the train stopped at Huntingdon for a quarter of an 
 hour. I had noticed, just before we entered the station, 
 the escarpments on either hand, and the debris at 
 their base * and so, when the train stopped, I hastened, 
 hammer in hand, to interrogate the rocks as to their 
 position in the geological scale. I had no map with 
 me, and with the exception that I knew I was some- 
 where upon the middle of the secondary rocks, I was 
 quite ignorant of their true position. After turning 
 over a few stones, I succeeded in hammering out a 
 fossil oyster whose species told me as plainly as the 
 best geologist could that the rocks in question belonged 
 to the middle oolite; for that species of oyster is 
 peculiar to those beds. This fossil further told me 
 that it must have lain for a long time on the old sea- 
 bed, for it was grouped all over with serpula, a kind 
 
POPULAR GEOLOGY. 107 
 
 of marine worm which makes a tube, and which may 
 still be seen on the backs of the shells of the oysters 
 brought to market. 
 
 Thus, you will perceive the value which is attached, 
 and very properly, to organic remains, in order to 
 enable the student to assign to any surface-rock its 
 place in the geological scale, and also to reason from 
 that circumstance as to what beds are absent, and 
 what may probably be found below. Had this know- 
 ledge, the acquaintance with only a few organic 
 remains, been possessed by many an intelligent specu- 
 lator in coal-mining, it would have saved many 
 thousands of pounds. Old William Smith, in his 
 " Stratigraphical System," had an insight into the value 
 of fossils when he said " Organized fossils are to the 
 naturalist as coins to the antiquary ; they are the 
 antiquities of the earth ; and very distinctly show its 
 gradual, regular formation, with the various changes 
 of inhabitants in the watery element." Not less 
 great was the value which Cuvier attached to them, 
 for we find him saying, "without (fossil) zoology, 
 there is no true geology." 
 
 Seeing the importance, therefore, of organic remains, 
 many of you may be led to inquire "are they found 
 in sufficient quantities to serve as guides 1 " I answer, 
 they are. Great variation, however, prevails in their 
 distribution, for, while some rocks are composed of 
 scarcely anything else, other rocks contain but few, if 
 any ; although the relation of this latter class of rocks 
 to the rest may be easily discovered by a due com- 
 
108 POPULAR GEOLOGY. 
 
 parison. Professor Owen, speaking of the distribution 
 of fossils, says, " Remains of invertebrate animals occur 
 in strata of every age, from the partially metamorphic 
 and crystalline rocks of the Cambrian system to the 
 deposits formed by the floods of last winter, and tides 
 of yesterday. They are found in every country, from 
 the highest latitudes attained by Arctic voyagers to 
 the extremities of southern continents ; and at the 
 greatest elevation hitherto climbed in the Andes or 
 Himalayas." From the most recent census in fossil 
 conchology we learn that the number of species of 
 univalve shells is nearly 6000, whilst the fossil bi- 
 valve shells amount to more than .that number ; the 
 species existing now scarcely exceeding half that 
 number. 
 
 One of the most beautiful analogies as to geological 
 reasoning ever wiitten, is that given by the late 
 Professor Silliman. He illustrates the nature of geo- 
 logical evidence by the buried cities of Pompeii and 
 Herculaiieum. After referring to the fact that history 
 repeatedly mentions the existence of those cities, but is 
 wholly silent upon their destruction, he says, " In 
 1738, when the workmen, in sinking a well, struck 
 upon the theatre of Herculaneum, which had been 
 buried for seventeen centuries ; when, subsequently, 
 Pompeii was disencumbered of its volcanic ashes, and 
 thus two ancient cities were brought to light ; had 
 history been as silent respecting their existence as it 
 was of their destruction, would not all observers say, 
 and have not all actually said Here are the works of 
 
POPULAR GEOLOGY. 109 
 
 man, his temples, his houses, furniture, and personal 
 ornaments ; his very wine and food ; his dungeons, 
 with skeletons of the prisoners chained in their awful 
 solitudes, and here and there a victim overtaken by the 
 fiery storm ? Because the soil had formed, and grass 
 and trees had overgrown, and successive generations of 
 men had erected their abodes over the entombed cities, 
 and because these were covered with lava and cinders 
 does anyone hesitate to admit that they were once 
 real cities ; that they stood upon what was then the 
 surface of the country ; that their streets once rang 
 with the noise of business ; their halls and theatres 
 with the voice of pleasure ; and that they were over- 
 whelmed by the eruptions of Vesuvius, and their 
 places blotted out from the earth and forgotten ? These 
 inferences no one can dispute all agree in the con- 
 clusions to be drawn. When, moreover, the traveller 
 sees the cracks in the walls of the houses of Pompeii, 
 and observes that some of them have been thrown out 
 of the perpendicular, and have been repaired and 
 shoved up with props, he infers that the fatal convul- 
 sion was not the first, and that these cities must have 
 been shaken to their foundations by the effects of 
 previous earthquakes. In like manner, the geologist 
 reasons respecting the physical changes that have 
 taken place on the surface of our globe. The crust of 
 the earth is full of crystals and crystallized rocks ; it 
 is replete with the entombed remains of animals and 
 vegetables, from mosses and ferns to entire trees 
 from the impressions of plants to whole beds of coal. 
 
110 POPULAR GEOLOGY. 
 
 It is stored with, the remains of animals, from the 
 minutest shell-fish to the most stupendous reptile. It 
 is chequered with fragments, from fine sand to enor- 
 mous blocks of stone. It exhibits in the materials of its 
 solid strata every degree of attrition \ from the slightest 
 abrasion of a sharp edge or angle, to the perfect 
 rounding which produces globular and spheroidal 
 forms of exquisite finish. It abounds in dislocations 
 and fractures ; with injections and filling up of fissures 
 with foreign rocky matter ; with elevations and de- 
 pressions of strata in every position, from the horizon- 
 tal to the vertical. It is covered with the wreck and 
 ruin of its former surfaces ; and, finally, 'its ancient 
 fires, although for a while dormant, have never been 
 wholly extinguished, but still find an outlet through 
 volcanic mouths. When we reflect upon these 
 phenomena, we cannot hesitate to infer that the pre- 
 sent crust of the earth is the result of the conflicting 
 energies of physical forces, governed by fixed laws ; 
 that its changes began from the dawn of creation, and 
 that they will not cease till its materials and its physi- 
 cal laws are annihilated." 
 
 JSTow this principle of identifying any rock by the 
 fossils which it contains, is very much like that which 
 naturalists pursue in the stud} 7 of existing creatures. 
 At the present time, the numerous species of shell-fish 
 which live in our seas are so characteristic of different 
 zones as to enable conchologists to group them into 
 different provinces, which generally take their name 
 from the geography of the places where they are 
 
POPULAR GEOLOGY. Ill 
 
 found. Thus we have the Arctic province, the Boreal, 
 the Celtic, the Lusitanian, South and West African, 
 Indo-pacific and others. There are certain genera and 
 species of living shells which are almost as character- 
 istic of these various provinces as the fossils are of the 
 different formations, and a good conchologist can tell 
 by the fades, or general appearance of a group of 
 shells, the several provinces to which they belong. 
 
 In like manner the vegetable kingdom is mapped 
 out into vegetable provinces, which are twenty-two in 
 number; each province being characterized by its 
 peculiar vegetable types. Again, just as the animals 
 which were low in organization survived the more 
 highly organized in range of time, so do we also find 
 the lower types of the vegetable kingdom, of the pre- 
 sent day, most widely extended in space, I refer to 
 such low types of vegetation as mosses, lichens, fungi, 
 &c. These are the most extensively and widely 
 diffused, and, while the higher orders nourish only in 
 their peculiar zones, which are sufficiently distinct 
 to be mapped out into provinces, these humble forms 
 of vegetable life connect, as by a huge bracket, the 
 whole of the provinces, and extend almost from the 
 ^"orth Pole to the South. 
 
 In thus laying before you the outlines of geological 
 science, I do not wish to leave you with the impression 
 that it is much easier than the rest. All knowledge 
 must be worked for, and our peculiar branch of it is 
 no exception. After all I have said of the regular 
 sequence of the geological formations, some of you 
 
112 POPULAR GEOLOGY. 
 
 may not know how or where to begin, or where to 
 look for them. Others of you may live in districts 
 comparatively flat, and where the soil is underlay ed 
 with beds of gravel and clay. In such districts much 
 patient investigation is required, and the geological 
 student must plod many a weary mile ; must look for 
 every rivulet and brook ; river-side and railway cut- 
 ting ; for it is in such places that the underlying rock 
 is generally found cropping out. Most of you, who 
 are acquainted with the packing of Manchester goods, 
 know, that after their encasement in layers of strong 
 paper, an end of the enclosed cloth is left hanging out, 
 in order to indicate, without the trouble of unwrapping, 
 the kind and quality of the cloth within. Now 
 river-side and railway sections serve to the student 
 exactly the same purpose, for they indicate to him the 
 underlying deposits most plainly. And it is in such 
 places where we find that Nature has " ticketed " her 
 productions of a long anterior age. 
 
 Thus, the principles of geological classification enable 
 us to erect, out of the apparent confusion and chaos of 
 former creations, a system of regularity and succession ; 
 and, through the same principles we come to the grand 
 conclusion that in time, as in space, Milton's immortal 
 
 line holds good- 
 
 " Order is heaven's first law." 
 
POPULAR GEOLOGY. 113 
 
 LECTUKE IV, 
 
 SAND, GEAVEL, AND CLAY; AN OUTLINE 
 OF THE DKIFT FOEMATIOK 
 
 The subject I have chosen for this lecture is " Sand, 
 gravel, and clay ; or, an Outline of the Drift Forma- 
 tion." I have selected this in preference to " Coal," 
 more particularly because Professor Kogers took that 
 subject, and I decline following in the footsteps of 
 such a well known and so eminent a geologist. 
 Another reason for my selection of the subject, " Sand, 
 gravel, and clay ; or, an Outline of the Drift Formation," 
 is, that the references to it are more locally abundant 
 than that of " Coal," and I hope to illustrate this 
 lecture by referring to various beds of gravel, or sand, 
 or clay, which most of us have come across during our 
 rambles. In the first place we are all of us acquainted 
 more or less with the general appearance of sand and 
 gravel. Eemarkable as it may appear to us it has a 
 geological history which equals, if not transcends, the 
 geological history of other formations. 
 
 Geologists were unable, until recently, to trace the 
 
114 POPULAR GEOLOGY. 
 
 history of our old earth, with all its cosmical pheno- 
 mena, up to the time when these beds of sand, gravel, 
 and clay, were formed. Beginning with the early 
 Cambrian period, they could follow up through the 
 Palaeozoic, through the Secondary, and even to the 
 termination of the Tertiary formations in an almost 
 unbroken sequence. Professor Sedgwick, some time 
 ago, made the remark that "Geological history was 
 broken off at each end." Beyond the Laurentian there 
 descends a curtain which no geologist has ever yet 
 been able to raise ; and at the close of the Tertiary 
 the curtain again descends prior to the appearance of 
 man. Owing, however, to the labours of geologists in 
 various parts of Europe and North America, to the 
 labours of geologists scattered far and near, some idea 
 of these beds of sand, gravel, and clay has at length 
 been attained ; and it is not too much to say that the 
 Drift formation, as a formation, is as distinct in its 
 phenomena, is as clearly fruitful in evidence of broad 
 design, as is the Coal formation, the Oolite formation, or 
 the formation of igneous rocks. Nay, I durst even go 
 beyond that, and declare, that at present the Glacial 
 period another name given to the Drift formation is 
 better known than many of its older relatives. 
 
 The connection between the Glacial period and its 
 immediate antecedents is more close than that which 
 exists between many geological formations. From the 
 earliest Tertiary period the time of the vast beds of 
 clay upon which London stands, and which take the 
 name of the metropolis, the time of the vast beds of 
 
POPULAR GEOLOGY. 115 
 
 gypsum and marl upon which. Paris and Vienna stand 
 from the very earliest period of the Tertiary forma- 
 tion to the very latest date, when the mosses and peats 
 of the neighbouring fens were deposited, there is clearly 
 a sequence throughout, and as evident a connection as 
 'though the links of the chain were hanging to one 
 another. Various parts of Europe have been ransacked, 
 and various parts of America, Australia, and the 
 Arctic and Antartic circles have been explored, in 
 order to furnish illustrations. Conchology has con- 
 tributed its quota ; botany, also, has contributed its ; 
 and comparative anatomy has been hard at work with 
 fragments of bone to throw a world of illustration 
 upon the subject. Physical geography has been 
 studied most minutely during late years, and the whole 
 of this knowledge has been thrown into the treasury 
 of this one particular subject, until the question of the 
 formation of our sand, gravel, and clay beds is almost 
 settled. There can hardly be any doubt as to their 
 origin, or as to the agencies which have been at work 
 to produce them, and as to the physical circumstances 
 which existed during the long period when these sand, 
 gravel, and clay beds were deposited in cold seas. 
 
 We are all of us acquainted with the appearance of 
 sand and gravel. To visit a sand or gravel-pit, how- 
 ever, with the eye of a casual observer, and to go to 
 one with the eye of a geologist, are very different 
 things. The geologist, has an eye which can detect in 
 rolled fragments of shells, a peculiar water-worn 
 pebble, a scratched or striated boulder, all the 
 
 i2 
 
116 POPULAR GEOLOGY. 
 
 agencies which, have been at work in forming and 
 depositing those beds. He will see by the hinge of 
 the fragment of a shell which he collects the species 
 and the genus to which it belongs, whether it be arctic 
 in its character or sub-arctic, whether it belong to the 
 Celtic province which still obtains in our seas, or 
 whether it be a rolled fragment which has been 
 brought from a more southerly direction. In like 
 manner the pebble will tell him whether it has been 
 obtained from the neighbouring rocks, and if so, 
 where ; whether it has been subjected to much water- 
 rolling influence, or whether it has been brought by ice. 
 Whether it has been carried from Scandinavia, from 
 the North of Scotland, from the Midland counties, 
 from Wales, or from various places where the parent 
 rock of which it is a fair representative exists. He 
 then adduces the natural theories that some changes 
 have been at work from that direction in conveying 
 these same fragments from the parent rock. Now, 
 perhaps, one of the most common features in a sand- 
 pit is the appearance of false bedding which we may 
 perceive. On going into a sand-pit, possessing a section 
 of some twelve feet in height, the first thing that strikes 
 the eye is this : that planes of bedding do not lie alto- 
 gether in a horizontal position. Generally speaking there 
 is a false bedding, as though the beds had been formed 
 along an inclined plane ; and as though the top of this 
 same false bed had been worn by the action of waves, 
 and another series of deposits planted upon it. These 
 facts are strongly in favour of shallow water influences. 
 
POPULAR GEOLOGY. 117 
 
 There must have been a commotion in the waters 
 before they could deposit these false beds. Again, 
 further examination will show us that this same sand 
 is composed, not altogether of particles of silica, not 
 altogether of what is commonly termed sand, but that 
 it is commingled in this part of the country (Norfolk) 
 more particularly, with eroded chalk, or fragments of 
 chalk fossils. And, further, these rounded fragments 
 of rolled shells, when examined by the microscope, 
 are seen to possess the curious structure which various 
 families of shells exhibit. In some places where 
 watery action has not been so violent, shells are 
 found in a still more definite state of preservation. 
 Sometimes they are not even water-worn, perhaps 
 hardly broken ; as, for instance, between Stoke Holy 
 Cross and Saxlingham there is a sand-pit on the left 
 hand side in which is a seam of about two and a half 
 inches in thickness, lying almost in the midst of a 
 vertical section of some fifteen or twenty feet. In 
 this seam there are some fragments of shells, (I myself 
 obtained no fewer than thirteen distinct species,) 
 mostly water worn, bearing evidences of arctic con- 
 ditions, and lying in the midst of the Middle Drift, 
 which caps the lower boulder-clay. Wherever those shells 
 occur, generally speaking, the strata do not exhibit 
 this false bedding; they generally lie in even and 
 parallel lines, as though the conditions under which 
 they had been deposited had been more regular than 
 in the former case. When we remember that the sands 
 where we find these shells are generally within a few 
 
118 POPULAR GEOLOGY. 
 
 feet of the surface, that they had been subjected for 
 thousands of years to the percolation of running water, 
 water which, when it has descended from the 
 atmosphere holds in solution some portion of carbonic 
 acid and humic acid, we cannot wonder that these 
 various sand-beds should be often altogether devoid of 
 shells, for the acids, during long thousands of years, 
 must often have dissolved every particle of shell, 
 whilst those which remained have been preserved under 
 peculiar circumstances. Apart from this, there are, 
 besides, particles of shells of arctic character, mingled 
 with the boulder fragments of rocks not existing in 
 Norfolk, not even within a radius of fifty, one hundred, 
 or some hundreds of miles. They are well worn, as 
 though they had come from a distance, and been com- 
 mingled in strange brotherhood with rolled pebbles 
 and flints obtained from the chalk which has been 
 eroded away, and left boulders in situ. In connection 
 with those shells some fragments of foreign rocks, if I 
 may so term them, exhibit plainly that there must 
 have been a peculiar condition in the formation of 
 these same beds. Were many of these gravel beds, 
 containing pebbles from "the size of a common walnut 
 and upwards, to have been hardened into solid stone, 
 they would resemble the conglomerate of the old red 
 sandstone, or of the older Cambrian beds. These 
 were evidently formed under similar conditions, ^ow, 
 when we examine some of the beds of conglomerate 
 in the Old Red Sandstone, we find pebbles of Silurian 
 rocks, that is to say rocks containing Silurian fossils. 
 
POPULAR GEOLOGY. 119 
 
 For instance, just in the north-west side of the Isle of 
 Man a piece of the Old Eed Sandstone conglomerate 
 caps the Cambrian, whilst the Cambrian rises in 
 almost a perpendicular position, and for a thickness of 
 fifteen feet, extending over three or four square miles 
 is a little piece of the sandstone conglomerate the 
 pebbles are nearly all derived from Silurian rocks, and 
 each pebble exhibits the peculiar Silurian fossils 
 characteristic of the formation. The inference is plain 
 enough. The geologist sees in them the broken up 
 fragments of an old Silurian land, a land which had 
 been re-deposited at a time when the sea was violent 
 in its aggressions, and so had formed a deposit of 
 conglomerate belonging to another and a later geologi- 
 cal epoch. 
 
 We perceive, therefore, that the sea-bottom upon 
 which this conglomerate was deposited was afterwards 
 upheaved, was subjected to the same mighty agencies 
 which had formerly acted upon the old Silurian shores, 
 and that out of all this wear and tear, going on for 
 millions of years, is left only this single outlier of 
 some four or five square miles ! However, this is to 
 be said that in the case of this conglomerate the 
 pebbles are nearly all Silurian. Here and there we 
 may meet with some pebbles of the underlying 
 Cambrian strata, but all prove that they have not come 
 from a distance. We can go, " as the crow flies," to 
 where we come upon similar beds of conglomerate, 
 belonging to the Devonian formation, or, at least, 
 representatives of it, and the natural inference is that 
 
120 POPULAR GEOLOGY. 
 
 the sea betwixt Ireland and the Isle of Man was once 
 occupied by an old Silurian shore a shore which was 
 broken up in order to form the same pebbles of the 
 conglomerate. What I wished to show was that in 
 this case there is no appearance of the same agencies 
 having been at work as those we see in the common 
 gravel pits ; that is to say, the pebbles are nearly all 
 brought from a short distance,, not having that cha- 
 racter which we preserve in our common gravel beds. 
 In the north of England these gravel beds are more 
 strange than we behold them in Norfolk. There we 
 find a geological parliament, in which true represen- 
 tatives of every geological formation, from the earliest 
 almost to the most recent are assembled. I do not know 
 of a better place to study mineralogy than in a common 
 gravel pit in the northern and midland counties of 
 England. In Norfolk the majority of pebbles, as is 
 usually the case, is of flint, broken and well rounded. 
 , Occasionally we meet with a fragment of red or grey 
 granite, which could not have come from nearer than 
 the high mountains of Cumberland and Wales, and in 
 the upper boulder-clay, which forms the cliffs along 
 the Norfolk coast, we have boulders, from the size of a 
 walnut to larger than a man's head, which must have 
 come in the drift stream, from no less a distance than 
 Scandinavia. 
 
 We have, therefore, forced upon our attention, in 
 studying these sand and gravel beds, the evidence that 
 a colder climate formerly existed in these regions a 
 climate similar to that now existing in Iceland and 
 
POPULAR GEOLOGY, 121 
 
 Greenland ; for shells now living in the North Atlantic 
 and Greenlandic seas are often found in similar 
 proportions in our sand and gravel beds. Again, we 
 have the occurrence of these foreign pebbles, coming, 
 not from the south, not from the west, not from the 
 east, but from the north, whence they were brought 
 by some peculiar agency. This occurrence, however, 
 supplements the finding of the arctic shells, and 
 proves that the agencies which have been at work in 
 bringing down these pebbles must have been in con- 
 formity with the cold condition to which the arctic 
 shells testify, and that they were brought down by 
 glacial and iceberg action. 
 
 Again, in the boulder-clay beds, most of the boul- 
 ders of larger size are not only well rolled and polished 
 almost as much as if they had been blackleaded 
 but they bear distinct striations, marks, or scratches, 
 as though they had been cemented into some solid 
 body, and grated on some hard substance, as a piece of 
 sand paper held tightly in the hand would leave its 
 trace upon glass. There is only one inference in 
 respect to these marks or striae. It is impossible for 
 them to have been made by running water, or by 
 stones rubbing against each other. Take any stone 
 from the river bed and you will find if any pebble 
 has marks upon it they are greatly different to those 
 you find in the boulder formation. Another thing is 
 to be observed. The upper and lower boulder-clay in 
 Norfolk, as exemplified along the coast, obtain an 
 enormous thickness in the midland counties. They 
 
122 POPULAR GEOLOGY. 
 
 are even thicker still in the neighbourhood of Man- 
 chester ; where they are sometimes no less than two 
 hundred feet in vertical thickness all formed of 
 impalpable mud ! It is in the bed overlying lower 
 boulder-clay we find most of the shells, for the cha- 
 racter of the overlying bed has preserved them intact. 
 It is evident that the mud covered them up and pro- 
 tected them before any destroying agency could be at 
 work. Hence those shells are few and far between. 
 They are generally found isolated and well preserved, 
 and, what is most singular, they are often found 
 in little nests, as though they lived gregariously 
 until some mud debacle entombed them and provided 
 them with an everlasting sepulchre. It is further 
 evident that the agencies at work must not only have 
 been enormous in their character to have formed a bed 
 say of twenty five or thirty yards in thickness, but 
 they must have extended over a vast period of time. 
 There is a bed of impalpable mud thirty yards in 
 thickness extending over hundreds of square miles, 
 not of the same nature as the Kimmeridge clay in the 
 oolitic series, but as distinct in its character as any of 
 the other geological formations, proving that whatever 
 agencies formed it those agencies must have extended 
 over an immense period of time and have been tolerably 
 uniform in -their character. ISTow, as I before re- 
 marked, the boulders found in this clay are nearly 
 almost all of foreign origin. Rarely do we find any in 
 either the upper or lower boulder-clay which are 
 native, that is to say derived from native rocks rocks 
 
POPULAR GEOLOGY. 123 
 
 immediately underlying the drift series. Granite, 
 syenite, porphyry, trap, basalt, all these are found in 
 immense quantities rocks of the harder character 
 and but rarely possessing an angular form. They are 
 often well water-worn, polished and scratched. The 
 shells associated with them also, are arctic in their 
 character, especially in the middle series of sands and 
 gravels. Now we have to cast about us in order to 
 find agencies still at work which can explain how 
 these same beds of clay were formed. The nearest 
 approach is when we examine the grinding and the 
 pounding everlastingly going on by the glaciers which 
 cover the highest peaks of the 'Alps, or when we go to 
 that ice sheet which covers the northern continent of 
 Greenland for more than eight hundred miles each way 
 an ice sheet no less than two thousand feet in 
 vertical thickness, upon which no living things can 
 grow. The whole of this ice sheet is in motion towards 
 the sea, crushing and pounding the rocks which rest 
 underneath it. There are, also, constantly running, 
 immense streams, caused by the melting of the ice, and 
 these streams carry away enormous quantities of the 
 mud which has been formed by the agency of the 
 glaciers. This mud is carried away to and deposited in 
 the adjacent sea. This same glacier terminates in the 
 sea, where there is a sheer precipice of two thousand 
 feet of solid ice. ' The ice is broken off in immense 
 fragments, many of them fracturing rocks over which 
 they have passed in their slow journey, and as they 
 fall into the sea they form icebergs, some of them no 
 
124 POPULAR GEOLOGY. 
 
 less than thirteen miles in length, and as much as one 
 hundred and fifty or two hundred feet in height above 
 the surface of the sea. Their specific gravity is such 
 that they must be eight times as heavy below as above. 
 Fancy an iceberg three miles in length having a height 
 above the sea-level of one hundred feet, and a depth 
 below of eight hundred feet, riding along at the rate 
 of four or five miles an hour and many of them have 
 been seen travelling at that rate ! How they must 
 grate at the sea-bottom when they became stranded ; 
 What powerful agents they must be in producing the 
 phenomena we see along our Norfolk coast, and which 
 are almost universal wherever the drift is found. 
 Great beds of sand and gravel are to be met with 
 everywhere along the coast where the drift formation 
 is to be found. Now, this mud, carried down by the 
 melting of the glaciers in Greenland, is strewn in the 
 neighbourhood of the sea bottom. The tidal action is 
 strong, the current action is strong, and the mud is 
 very fine and can be carried out to sea for two or 
 three hundred miles together. In these same seas are 
 living molluscs of an arctic character. These molluscs 
 are not immortal. They have their own lifetime ; they 
 are also subject to accidents, as every living thing is ; 
 and the consequence is that all the different shells get 
 buried up in the mud. This mud is deposited at an 
 enormous rate, the formation having been going on 
 long before the historic period, and even now we have 
 this same work going on along Greenlandic shores. 
 We find the drift beds covering the old world as low 
 down as the forty-fifth parallel of latitude. 
 
POPULAR GEOLOGY. 125 
 
 Now, there are distinct evidences of the rigorous 
 climates which once obtained in these latitudes, being 
 of gradual growth. In the London clay are beds of 
 clay which, by the way, often very much resemble the 
 more stratified beds of the Boulder formation, but, un- 
 like them, they are devoid of boulders. In them we 
 find remains of animals, many of them extinct, and 
 many others resembling animals no longer living in 
 these latitudes. Unlike the shells found in the boul- 
 der-clay, the shells and the animals found in the 
 London clay resemble more nearly those living in 
 southern latitudes. The London clay furnishes us 
 with remains of crocodiles, with the vertebrae of ser 
 pents as large as the boa-constrictor, with remains of 
 the monkey family, and with remains of fresh water 
 fish, and shells similar to those living in warmer lati- 
 tudes. Amongst fossil botany we have the remains of 
 the bread-fruit tree, similar to those now living in the 
 islands of the Pacific ; the plantain, the cassave, the 
 palm, and many others, nearly all of which prove that 
 these beds of London clay were deposited, not under 
 arctic conditions, but under tropical, or at least sub- 
 tropical, the whole resembling the state of nature in 
 existence in the Malayan archipelago. If we go fur- 
 ther to the north, we find beds exhibiting a similar 
 warm climature. Later than the Eocene or London 
 clay, we have beds where fruits of the palm are pre- 
 served, where remains of tropical shrubs are met with, 
 all proving that these beds, lying within the radius of 
 the arctic circle, had a climate more like that now ex- 
 
126 POPULAR GEOLOGY. 
 
 isting in the East or West Indies than anywhere else. 
 The Eocene formation is followed by a series of deposits 
 on the continent which are classed as Miocene. These 
 are very scantily represented in this country, although 
 there are vast beds of Lignite, in which we find tropical 
 plants and remains of marine shells, exhibiting a 
 warmer climate than that which now obtains, but not 
 so warm as that which prevailed during the formation 
 of the London clay. Then follows the Pliocene, repre- 
 sented in this country by the Suffolk and Eed or 
 Coralline Crag. Now the red crag and the coralline 
 crag prove that a much warmer climate prevailed during 
 their deposition than that which now exists in the 
 same latitudes, although this climate seems to have 
 been more like that of the south of Italy, than any 
 other. No less than twenty species of shells, allied to 
 those now found in the Mediterranean, are found in 
 the coralline crag, whilst there is one species now living 
 in the West Indies. The number of shells found in 
 the coralline crag akin to those still living in southern 
 seas, is fifteen species. 
 
 When we come to the red crag, we find that a gra- 
 dual cold had been coming on ; and that a gradual 
 decrease in the climature had taken place, This is 
 exhibited by the number of the shells found. The number 
 of southern shells found in the red crag is only eleven 
 per cent., and for the first time in conchological history 
 this same red crag produces eleven species of northern 
 shells, principally allied to those now living off the 
 north coast of Britain. Then follows the Norwich 
 
POPULAR GEOLOGY. 127 
 
 crag. In this deposit we do not meet with a single 
 southern shell ; whereas the number of northern spe- 
 cies is fifteen. These three crags exhibit the gradual 
 decrease in climature, as well as the gradual increase 
 of cold, that was going on over these latitudes, as 
 plainly and perfectly as possible. Not only by the 
 decrease of the southern shells until we find more in 
 the Norwich crag is this shown, but by finding an 
 increase in the northern shell in the Norwich crag. In 
 the upper crag, at Bramerton, we have completed the 
 teaching which the rest of geology adduces from the 
 very earliest period of the Eocene. This decrease of 
 heat is shown, as I have already pointed out, through 
 all the formations and crags, until it reaches the fourth 
 bed at Bramerton, where shells are found in situ with 
 both valves adherent, and where the proportion is 
 vastly of an arctic character. 
 
 Then comes the drift formation, into which these 
 beds of crag glide. I mentioned the gradual decrease 
 of cold, in order to show what the geological evidences 
 were before the drift formation was studied as a geolo- 
 gical one ; and now, when we come to study this for- 
 mation in various parts of Europe, in North America, 
 in fact wherever we come across it, we find that it 
 supplements the distinct teachings of prior formations, 
 that cold, instead of heat, reached its maximum during 
 the beds known as the drift formation, or northern 
 drift. Now, wherever we find hard rocks, underlying 
 the boulder formation, we almost invariably find them 
 scratched and polished in such a way as to leave no 
 
128 POPULAR GEOLOGY. 
 
 doubt upon the mind of the observer, however super- 
 ficial a geologist he may be, that these scratchings and 
 planings had been caused by the wearing and pounding 
 agencies of ice, similar to that now going on in the 
 northern continent of Greenland. The hardest rocks 
 are subjected to it. In the North of the Isle of Man, 
 there is a vast sheet of mountain limestone one of 
 the hardest rocks in the whole series which is polished 
 as distinctly, and scratched as sharply, as are the slabs 
 out of the same formation in Derbyshire, for the pur- 
 pose of making our mantel-pieces. Upon this the 
 boulder formation distinctly rests, and whenever there 
 comes a more than usual shower of rain, or a violent 
 storm, the rain and sea acting upon the clay resting 
 upon the limestone causes it to shunt down in enor- 
 mous landslips, leaving the whole of the polished and 
 scratched surface of limestone open to the view. In 
 other parts, in Scotland, and Wales, the same phe- 
 nomenon is to be observed. 
 
 Now, again. When we examine our hill tops, the 
 lakes, the defiles and passes over mountains, we every- 
 where find that ice has left its mark upon them. 
 Enormous glaciers have slidden down the peaks into 
 valleys, pounding, crushing, and tearing everything with 
 their weight. Most of the valleys between those high 
 mountains, nearly all the northern lakes, and almost 
 all the lakes in existence in Northern Europe and 
 America, have been scooped out by ice agencies ! In 
 Scotland we can trace the direction the glaciers for- 
 merly took by miles of grooves, which they left as they 
 
POPULAR GEOLOGY. 129 
 
 glided down the valleys. We can trace these marks 
 following the side of the valley, showing that the sheet 
 of ice which travelled thence debouched into the open 
 sea, and left its marks upon the walls and fissures on 
 every hand. Some of the bottoms of the Swiss lakes 
 are below the surface of the sea. Lucerne is at least 
 a hundred and fifty feet below sea-level, and no super- 
 ficial action, except that of ice, could have scooped it 
 out. The lake does not lie in an anticlinal valley, but 
 is scooped out of the solid material ; the strata passing 
 from one side of the valley to the other. In Scotland, 
 according to Mr. Jameson, immense masses of ice have 
 often forced their way down the valleys, and up the 
 other sides ; so that, where the pressure has been 
 greatest, that part has been more deeply scooped out. 
 When the ice was removed, in many cases the valleys 
 were filled with fresh water lakes. The same phe- 
 monena are exhibited in New Zealand and Australia ; 
 in fact, fresh water lakes, in almost every instance, 
 are attributable to glacial action. 
 
 The evidences of intense cold which once existed in 
 this country, are not limited to the facts I have already 
 adduced. You will have perceived already, in the 
 theory I have advanced, that this intense cold is but a 
 common-sense view of the question. Now, in addi- 
 tion to this evidence of glacial action, and of the 
 intense cold which prevailed in these latitudes when 
 these beds of sand, gravel, and clay were formed, there 
 are additional evidences. Along the Norfolk coast, 
 there is a forest bed, known as the Cromer and Bacton 
 
130 POPULAE GEOLOGY. 
 
 Forest Bed, in which are found immense quantities of 
 trees, many of them lying in situ. By the way, this 
 forest bed is slightly older than the Norwich crag, and 
 just as the Norwich crag yields northern representa- 
 tives of shells, and exhibits the cold which was coming 
 on at the time, so this forest bed, immediately antece- 
 dent to the Norwich crag, exhibits in its vegetable 
 remains similar proofs of a cold climate. For instance, 
 even within historical times, the Scotch fir was un- 
 known in this country ; it was limited to Scotland. 
 The spruce pine is a native of Norway, and was not 
 known in this country until transplanted here. But 
 in the forest bed we meet with both these northern 
 trees in immense quantities, and the cones they shed 
 when growing are also left to prove their natural 
 habitats. When these trees grew, the land stood five 
 hundred feet higher than now, this country being 
 linked with Scandinavia. Lyell had shown that an 
 upheaval of six hundred feet would connect this island 
 with the north of Europe, so as to give an immense 
 prolongation of the continent. It was this which en- 
 abled the trees now found in the Norfolk forest bed 
 to migrate into this country. After this, the land began 
 to be gradually submerged, and to sink down, in the 
 neighbourhood of Greenland and along the Greenlandic 
 coasts, about three or four feet in a century. The water, 
 when thus submerging the land, gradually rose, even 
 above some of the mountain tops, and left a group of 
 wintry islands, now known as Great Britain. The 
 finding of arctic shells in the sand and gravel along 
 
POPULAR GEOLOGY. 131 
 
 our hill sides, proves that the country must gradually 
 have gone down, until nothing but the tops of our 
 highest mountains were visible in that wide- wintry sea. 
 Again, the botanist in his peregrinations, when he 
 passes his days and nights upon the mountain tops 
 in Great Britain, but particularly in the North of 
 England, will find rare isolated specimens of arctic 
 plants. How is this? Simply because the cold on 
 our mountain tops is more adapted to the arctic char- 
 acter of the plants than is the warmer atmosphere of 
 the plains below. Plants, like those in question, are 
 to be found in the forest bed, showing that when the 
 trees of that primeval forest grew, those plants migrated 
 into this country. As the cold increased, these plants 
 gradually crept up to the tops of mountains, the seeds 
 taking root where they could, but when the country 
 became uplifted again, the climate was changed to that 
 which now obtains, and they disappeared except from 
 the mountain peaks. These existing plants thus testify 
 to an age long gone by, and to the existence of arctic 
 conditions which once prevailed in this country. The 
 naturalist, also, as he dredges the Irish seas, every now 
 and then comes upon immense, deep"holes. In these 
 he finds peculiar species of shells of a northern char- 
 acter. Just as the plants on the tops of our hills were 
 arctic in their character, so these shells, found in the 
 deeper parts of the British seas, are also arctic. There 
 is one often found in the drift formation, the Rhynco- 
 nella psittacea. This is a deep-water shell fish, and 
 lived in our seas at a time when the temperature was 
 
 K 2 
 
132 POPULA.R GEOLOGY. 
 
 suited to its habits. When the climate became warmer, 
 it was obliged to seek a fitting habitat, and to retire 
 into deeper water. Hence they are found in the 
 British seas but in deep water. These plants and 
 shells, therefore, testify to the former arctic condition 
 of this country, when the drift beds were formed. 
 
 After this submergence, when Britain existed simply 
 as a northern archipelago, there came another upheaval, 
 again joining England to the continent, when the 
 Germanic flora migrated into this country, such as the 
 daisy, the primrose, and other plants, pleasing to the 
 eye. It was just at this period in geological history 
 that we meet with the first traces of man. The climate 
 was still rigorous, and many of the higher mountains 
 were covered with glaciers ; still an amount of snow 
 and ice annually accumulated, and in consequence of 
 their melting, our rivers were broader and deeper than 
 they are now, and the tidal action was stronger. As 
 these rivers gradually scooped their way in their 
 passage to the sea they threw up along their sides gravels 
 forming the terraces we now see along their banks. It 
 is in these upper terraces, or river gravels, that we find 
 the flint implements, about which so much has been 
 said. After this there came another gradual upheaval, 
 during which the rivers retreated and formed another 
 bed of gravel, termed " low level " gravels. The flint 
 implements found in the higher level gravels are of 
 a peculiar shape, formed for the purpose of making 
 holes in the ice in order to obtain fish, as is now the 
 habit of the Esquimaux ; but flint implements in the 
 
POPULAR GEOLOGY. 133 
 
 lower level gravels appear to have been manufactured 
 in the shape of arrows and spear-heads, for hunting 
 purposes, showing that a warmer temperature had set 
 in. In the lower beds, too, were found remains of 
 extinct animals that were contemporary with man. In 
 the middle drift, and in fact through the whole of the 
 drifts, are remains of enormous mammalia. There are 
 several species of elephants, whose hides and hair were 
 evidences of the rigour of the clime in which they 
 lived. One species of elephant has been found 
 imbedded in Siberian ice with its flesh intact. All 
 these evidences point out the arctic conditions which 
 once obtained in this country. It is in the valley 
 gravels that we meet with the remains of the above 
 animals more commonly. There can be no doubt that 
 the early races of men were contemporary with later 
 races of these mammalia. Their bones are found in 
 strange companionship almost everywhere. We find 
 their bones cemented together in the caverns of Devon 
 and elsewhere, associated with the remains of human 
 art proving that even then man, with his scanty 
 intelligence, was able to subdue creation and make it 
 bend to his indomitable will. 
 
 When we come to study the geology of the various 
 parts of Norfolk, apart from these northern changes, 
 then we see evidences of geographical changes which 
 have been since at work to produce the present result. 
 For instance, when the drift formation existed, the 
 Swiss glaciers extended many miles further than they 
 do now. Many of the smiling valleys of Switzerland 
 
134 POPULAR GEOLOGY. 
 
 were formerly filled with some one thousand five 
 hundred or two thousand feet of solid ice. We now 
 find miles of moraine heaps, far away from where 
 glaciers terminate, all proving that the cold was 
 much greater in Switzerland formerly than it is at 
 present. At the present time the hot wind that blows 
 from North Africa, from the desert of Sahara, over the 
 Mediterranean, strikes against the Swiss mountains 
 and raises the general temperature of the Alps. In con- 
 sequence of this the formation of glaciers is arrested. 
 At the time the drift beds were in progress, the desert 
 of Sahara that great rolling bed of hot sand and 
 gravel was a widely extended sea, similar to that of 
 the Mediterranean. In the desert of Sahara, com- 
 mingled with the loose sand, are to be found fragments 
 of shell fish, such as the common cockle, greatly differing 
 from those now existing in those latitudes, and proving 
 the lower temperature of the Saharan sea. When this 
 sea existed no hot wind cquld arise ; and instead of that 
 the wind which blew across Europe was charged with 
 moisture, which descended on the higher mountains 
 and was turned to ice. Hence the evidences of greater 
 cold are to be met with in tropical as well as teni- 
 v perate latitudes. 
 
 Now, in my estimation, the evidences of design are 
 as broad in the drift formation as in the carboniferous, 
 with its immense store of coal. The various agencies 
 at work to produce the drift beds, the pounding of 
 rocks by the glaciers and icebergs, the commingling of 
 the different strata, the liberation thus of clay and 
 
POPULAR GEOLOGY. 135 
 
 sand, as well as of iron and phosphates from the fossils, 
 has formed a sub-soil in which all these various 
 mineral constituents are now mixed together for the 
 growth of vegetables, at the time when their culti- 
 vation is so necessary to millions of the human family. 
 The influences which have been at work in the drift 
 resemble those of a farmer who enriches the soil with 
 artificial manure in order to cause it to bring forth a 
 good crop of bulbs and cereals. Taking all these facts 
 together, the evidence of design are broad throughout 
 the whole drift formation, and tend to supplement the 
 teaching of all geology, that go downwards wherever we 
 will we cannot escape the Omniscient eye, which, ever 
 since the world existed, has been superintending its 
 progress ; in whose sight not a sparrow falls without 
 knowledge ; by whose aid a simple shell, a fragment 
 of bone, a piece of rock, or a particle of mineral, fur- 
 nishes its quota to Creation's great building, and helps 
 to produce the success, progress, and permanence of 
 the whole. " GOD HIMSELF FORMED THE EARTH AND 
 MADE IT; HE HATH ESTABLISHED IT, HE CREATED IT 
 NOT IN VAIN, HE FORMED IT TO BE INHABITED." 
 
 NORWICH : PRINTED BY FLETCHER AND SON. 
 
Now ready) reduced, price 3s. 6d., second edition, illustrated. 
 
 GEOLOGICAL ESSAYS; 
 
 BT 
 
 JOHJST E. TAYLOE. 
 
 LONDON : SIMPKIN, MARSHALL, AND CO. 
 MANCHESTER: A. IRELAND, PALL MALL COURT. 
 
 Opinions otf the itfyess. 
 
 "Any geologist will at once apprehend the features and 
 fossils afforded by such formations ; and anyone who is not 
 yet a geologist, may learn much from Mr. Taylor's easily- 
 understood essays on this subject and locality. With the 
 author we may ramble about villages in Cheshire, such as that 
 
 of Lymm The chief value of Mr. Taylor's book 
 
 is, that it gives references to fossiliferous localities. . . . 
 Books on such themes, by competent hands, will always be 
 interesting, even to general readers ; and the one before us, 
 which is composed of discursive essays clustering round the 
 central topic of the geology of the Manchester district, is good 
 in design and in execution." Athenceum. 
 
 " It is refreshing to take up a book on geology in which we 
 find ourselves free from the set phrases and pratings of the 
 old school of geologists, or the hackneyed and tiresome in- 
 
OPINIONS OF -THE PRESS. 
 
 veighings against the hard words of science, so common in the 
 multitude of works on so-called modern science. . . . The 
 general tenour of Mr. Taylor's essays is very good, and his book 
 is a very good and useful one, especially in all that he has to 
 say on the local geology of those districts in which he has 
 resided. The accounts of the Lancashire coal-field, and of 
 the strata in the vicinity of Manchester, are exceedingly 
 interesting, whilst the illustrations of fossil plants and shells 
 are very appropriately selected." Geologist Magazine. 
 
 "The author of the book which bears the above title, 
 [' Geological Essays,'] has given us a very pleasant production. 
 He writes nicely, and, being in possession of considerable 
 geological knowledge and literary culture, he has produced an 
 agreeably popularized medley." Popular Science Review. 
 
 " Several geological treatises have come into existence 
 during the past year, and among others we may mention the 
 following : Taylor's ' Geological Essays,' Ramsay's ' Physical 
 Geology and Geography of Great Britain,' &c. Mr. Taylor's 
 work is a sort of compound of the purely literary and scientific. 
 It treats of general geology, and every subject which can by 
 any possibility be associated with it. It is pleasant reading, 
 and, to some extent, profitable also." London Review. 
 
 " Mr. Taylor, in the excellent ' Essays,' of which he is the 
 author and which I would recommend for the perusal of 
 everyone, because they were written in the most glowing and 
 eloquent language, and were exceedingly interesting said 
 that flowers were only introduced into the world shortly before 
 the appearance of man, for its ornamentation, and for man's 
 pleasure ; and this, I believe, has proved to be the case." 
 Rev. John Gunn, F.G.S., in Geology of Norfolk. 
 
 " Mr. Taylor has recently published a volume of ' Geological 
 Essays,' of which I think very highly ; and, as they relate to 
 the geology of our own neighbourhood, it is only right, I 
 think, that some notice should be taken of them by the 
 Society. Mr. Taylor is a very sound geologist, and these essays 
 are written in a very popular strain, so that any general reader 
 
OPINIONS OF THE PRESS. 
 
 may be interested in the subject. He introduces a good deal 
 of general literature, and gives some highly interesting sketches 
 of excursions in different parts of the country. I think it 
 will be a very useful handbook for the geologists of the neigh- 
 bourhood, and it is certainly very creditable to the author." 
 Mr. Hull, F.G.S., in Transactions of the Manchester Geo- 
 logical Society. 
 
 " Another book of the season is Mr. John E. Taylor's collec- 
 tion of ' Geological Essays,' relating principally to the features 
 of the country in the neighbourhood of Manchester: . . . 
 This volume will be a very acceptable addition to the geological 
 department of our libraries. It deals intelligibly with facts, 
 and communicates many which are not generally known. The 
 author gives a significant impulse to thoughtful enquiry in the 
 direction where lie the recondite stores of Truth." Morning 
 Post. 
 
 "In selecting the ' middle ages' of geology as his special 
 subject, Mr. Taylor has been influenced by the opportunity 
 which Manchester affords for illustrating the later palseozoic 
 and the earlier mesozoic portions of ' The Great Stone Book.' 
 He does not limit himself to them, however, but traces the 
 record downwards and onwards from the Plutonic rocks to 
 the earth as we see it, reverently pointing out its gradual 
 preparations through countless ages for the happiness and 
 well-being of man. Mr. Taylor describes with unusual clear- 
 ness and beauty numbers of fossilized plants, &c., in which he 
 is assisted by woodcuts. . . . The relation of the little 
 holiday trips in search of specimens, and one especial visit to 
 the Derbyshire caverns, are really delightful, and leave little to 
 be desired." Globe. 
 
 u Mr. Taylor has here produced a book which will be likely 
 to interest in geological science many who now consider the 
 geologist simply a pedant of stones. He writes with a full 
 understanding of his subject ; and, more, he writes fluently 
 and in a wholesome spirit. .... Mr. Taylor quite 
 recognizes the scope of his book. He does not make essays 
 
OPINIONS OF THE PRESS. 
 
 lectures. He does not prose at all, or go too deeply into 
 detail. He has endeavoured to convey broad facts with their 
 
 legitimate inferences and appropriate conclusions 
 
 There is a peculiar freshness about the author's style, and 
 students will find his work a valuable assistance in their 
 researches. And general readers, who may desire to gain an 
 acquaintance with the present standing of the science, will be 
 pleased with the reverent manner in which Mr. Taylor ap- 
 proaches the subject." Morning Herald. 
 
 " Mr. Taylor's book is devoted principally to the geology of 
 the district surrounding Manchester ; and his essays are those 
 of a practical student, who gives an account of what he him- 
 self has examined in the field. . . . We can recommend 
 the book as being interesting to the general reader, and it 
 appears to be a treasure to the young geologist whose habitat 
 may be fixed in or near the district described, for it gives him 
 information as to what is to be seen and where to look for it." 
 Morning Star. 
 
 " In a city situated like Manchester, it is of importance that 
 there should be a handbook to the geology of its environs. 
 . . . We therefore welcome the work of Mr. Taylor as in 
 some measure retrieving the honour of the knights of the 
 hammer. . . . The work we have now the pleasure of 
 noticing, meets a real want in treating the subject in a popular 
 and agreeable style, and in combining matters of much specu- 
 lative interest with sound science, which, we are bound to say, 
 is a rare combination. Mr. Taylor is one of the few geologists 
 of Manchester who is equally at home among the strata of a 
 coal-field and those beyond its boundaries. He is known as an 
 ardent field- naturalist, and has in person explored the fine 
 sections along our river channels, climbed the cliffs of the 
 Penine Hills, descended the mine, and, with his own hammer, 
 disentombed the fossil remains of the rocks. Hence there is 
 a freshness and truthfulness in his descriptions, not to be met 
 with in works on natural history which emanate from the 
 library. . . . Mr. Taylor gives a lively description of the 
 
OPINIONS OF THE PRESS. 
 
 celebrated ' Speedwell ' cavern, near Castleton. This is a spot 
 visited by many tourists every summer, who cannot do better 
 than make this book their compagnon de voyage. In it they 
 will find figures of the shells and other fossils they are likely 
 to meet with, and descriptions combining a good deal of play- 
 ful fancy and literary lore. . . . The chapter devoted to 
 ' The Literature of Geology ' will repay perusal, and is one 
 over which we should gladly linger, did space permit. It is 
 the>>^ instance, in our recollection, of an attempt to gather 
 the scattered notices, in which British poets have deigned to 
 allude to a science in itself so full of poetry," &c. Manchester 
 Examiner and Times. 
 
 " Geology is fast becoming popular, and the ' Essays ' before 
 us will materially help on progress in that direction. Mr. 
 Taylor has adopted a light, graceful style, which involuntarily 
 leads one on until the whole attention is absorbed ,in the 
 subject. To do this requires a master's hand. ... It 
 would hardly have been difficult, even without the author's 
 intimation, to have discovered that many of these essays were 
 written or conceived during a few minutes' rest in some solitary 
 quarry, or on the green hill side. Every chapter speaks of 
 fresh air and out-door work." Salford Weekly News. 
 
 " The book is neither a strictly scientific treatise, nor by any 
 means a ' geology for the million!' It possesses a merit 
 rarely to be met with in works of its class, being at once 
 accurate and trustworthy in regard to science, and also 
 thoroughly readable, in some places delightsome. . . . Not 
 the least praise to be accorded to Mr. Taylor is that of writing 
 in a style equally exact, elegant, and forcible. . . . The 
 twenty-first chapter, that which terminates the volume, con- 
 tains remarks in respect of the religious pointings of geology, 
 which are especially to be noticed. They are philosophical 
 and fervidly religious." Rochdale Pilot. 
 
 " At the same time that Mr. Taylor enforces the necessity 
 of geological terms as ' the grammar of the science,' he holds 
 out ample compensation in the varied details and profound 
 
OPINIONS OF THE PRESS. 
 
 philosophical observations with which his essays are en- 
 livened. The * dry bones ' appear to be again indued with the 
 functions of life, and are clothed with rich and glowing lan- 
 guage. We venture to predict that this volume, from the 
 enlightened but strongly religious bias which pervades it, will 
 prove not only attractive, but also instructive in the highest 
 degree .' ' Norwich Mercury. 
 
 " The book is written in an exceedingly agreeable style, and 
 contains unmistakable proofs of a close and loving study of 
 the science of which it treats, and of a mind richly stored 
 with the choice products of English literature. . . . The 
 book appears to be a valuable contribution to the literature of 
 geology, and exhibits the science, not in a hard, dry, and 
 pedantic form, but in an inviting and attractive form, the 
 poetry of the rocks having occupied a large portion of the 
 author's attention." Norfolk News. 
 
 " To its literary merits we have much pleasure in bearing 
 testimony. Mr. Taylor . writes fluently and well, and has 
 evidently not confined his reading to the works of geologists 
 alone." Norfolk Chronicle. 
 
 In preparation, by the same Author, 
 
 in its Stfmjinp an h*ol0jgg. 
 
RETURN EARTH SCIENCES LIBRARY 
 
 TO > 230 McCone Hall 642-2997 
 
 CO 
 
 
 
 CN 
 
 *o 
 
 LOAN PERIOD 1 
 1 MONTH 
 
 ^t 
 
 oo g 
 
 
 
 
 
 
 ^x O 
 
 
 
 
 
 
 0> 
 
 2 
 
 
 
 
 
 1 
 
 O <u 
 
 LU id 
 
 UJ 
 CD 
 
 
 
 
 
 
 
 
 
 
 
 < o 
 
 UJ 
 
 UJ 
 Q. 
 
 S 
 
 
 
 
 
 LU * 
 
 L_ 
 
 
 
 
 
 CO 0) 
 < x ^ \r> 
 
 CO 
 
 
 
 
 
 _g 
 
 0) 
 
 
 
 
 
 oo v2 
 
 UJ 
 
 
 
 
 
 81 
 
 
 
 
 
 
 
 CO c " 
 
 
 
 
 
 
 I 10 
 
 
 
 
 
 
 < 1 
 
 
 
 
 
 
 CO 
 
 
 
 
 
 
U.C. BERKELEY LIBRARIES