







ciennes, there wouKl be no doubt of the decay of natural agencies ; 

 but thu u not allowable, for the great dislocations alluded to are to 

 be viewed as phenomena of a short interval of violent movements 

 between long period* of ordinary action such aa now obtains on 

 -. . ' . 



It may be supposed that the number of these cams of very great 

 and extensive disturbance U in proportion to the time elapsed ; but 

 as none such has occurred within the reach of history for at least 4000 

 years, we see how very ancient is the earth ; and further, we have no 

 data for accurately computing in numbers the vast periods which 

 ban elapsed in producing the stratified crust changing many times 

 its vegetable and animal races. On the whole, it appears that the day 

 is not arrived for theory to trust itself with the attempt to assign 

 definite values to the symbols of duration which remain in the earth. 

 Long, undoubtedly, perhaps as long as the periods which the study ol 

 planetary motion* lias revealed, must be the whole range of geological 

 time; but until we know at this day what ia the average rate of 

 deposit ion of sediment in the sea, or the u*ual ago of marine Mullu-wu, 

 until we can determine the numerical or structural relation! 1" 

 organic forms and physical conditions, or con convert the irregular 

 effects of volcanic fire.i into a calculable series of changes of tempera- 

 ture, there is little hope that the invitation of the Royal Society, to 

 awign the antiquity of the crmt of the earth, will be accepted by 

 prudent and competent geologists. 



Eftmomic'il Ai>i-ti<-utiont of Geological Science. "Practice," says 

 Professor Whewt-11, " has ever been the nurse of theory : art has ever 

 been the mother of science, the comely and buoy mother of a daughter 

 of for higher and serencr beauty. But the benefits are reciprocal ; 

 geology, nt least, is capable of well repaying the large debt which it 

 owes to the experience of the miner, the engineer, and the agricul- 

 turist, and indeed some of its truths ore already largely productive of 

 public benefit. 



" There is hardly a district in this island where the reasoning of 

 geology has not checked extravogeut expenditure in search of coal or 

 u: ores where such are not to be found, and conquered the 

 civilulity of ignorance ever ready to listen to the delusive and almost 

 superstitious notions of merely working colliers and miners. The 

 false and deceitful promise of finding good coal by going deeper, will 

 not often again lure the landed gentry and respectable companies to 

 such adventures as sinking for cool in the oolites of Oxford, the sand- 

 stones of Sussex, or the Silurians of Radnorshire. But it is not 

 merely by preventing foolish and wasteful expenditure, in search of 

 imaginary treasures, that geology has aided the mining interest : it is 

 within our memory that the eminent practical men of the great 

 northern coal-fields doubted or denied even the existence of coal 

 iiiiili-r the magnesian limestone. Yet now the Helton colliery, and 

 (in consequence of Dr. William Smith's geological opinions) the South 

 Helton colliery, send enormous quantities of excellent coal to the 

 London market from beneath the dreaded magnesian limestone. The 

 almost universal prejudice of colliers that ' Red rock cuts off coal,' 

 has been vanquished in Lancashire, Staffordshire, and Somersetshire, 

 and reasons have been given by Conybeare and others for believing 

 that under the red rocks of the midland counties great tracts of coal 

 remain for the public advantage and the triumph of geology." (' Phil. 

 Mag. and Annals.') 



Some years ago, Lord Dartmouth, guided by geological reasoning, in 

 opposition to the views of the local colliers, sunk a trial pit for coal 

 near Birmingham, and found it below red-randstonr rocks. It 

 was faulty near the pit bottom-; but this has not piwi nt< >! Ui. 

 establishment of a colliery, nor discouraged further attempts in the 

 vicinity. 



Coal-working. In the practical department of coal-working, geology 

 can as yet render little aid, because the experience of the coal districts 

 hai hardly yet been turned into science. The subject of the ' faults' 

 (' trouble*,' as they nre often and justly called), from which no coal- 

 field i* exempt, and which by their effects on subterranean drainage, 

 and thu disarrangement of the subterranean works, their influence on 

 the quality of the coal, and other circumstances, ore of the lm;lK ! 

 importance to the collier, is yet almost wholly unknown as a branch 

 of science. One general fact known concerning them (the com- 

 nre of the dip of the fault to the depression of the strain), may 

 be Illustrated in the subjoined diagram after Professor Phillips'*. 

 i Pit. 8. *' 



In thii figure the faults a, A, and .r, decline variously from the 

 u hh'; and they are most frequently found to dip or decline 

 under that portion of the divided strata Which is relatively depressed, 

 as a and 6, not as T, which represents a rare and exceptional case. 

 I!y the sides of faults the strata nre often slightly or considerably 

 bent, sometimes in the direction tending to unite their disrupted parts, 

 M ; sometimes in the contrary way, as It. In the former case they 



art) said to ' ris? to an upthrow, and dip to a downthrow;' in tli 

 latter they ' rise to a downthrow, and dip t> an upthrow.' If these 

 circumstances were carefully recorded by surveyors of col 

 science might eventually combine the detached facts into general 

 laws, show their dependence on other e iiidiiimiH, and thm put an 

 instrument of discovery into the hands of pract if il in" u. 



It i* a common thing to find valuable coal-beds at tirt injur. 

 ultimately rendered worthless, by the interposition of a w 'dgo or 

 band of rock, r, in some port of the thickness of the cool ; thus tlic 



Ki*. 9. 



High Main Coal of Newcastle is split, and in a particular din 

 ruined by the ' Heworth Band.' The upper part of the i 

 fordshiro coal-beds goes off in ' the Flying Reed ;' and tho t. 

 bed of liamsley in Yorkshire divides into almost unknown par 1 

 the details of colliery working were more complete I. th<! 



law of these phenomena could be more accurately traced, so as to 

 answer the anxious questions which such intrusive bands sugtr 

 coal proprietors. 



The variations of quality in coal, whether of different beds in tho 

 same district (a common caw), or of the same beds in <l 

 tricts (as in South Wales, where good furnace cml is found in thu 

 cast, and antharcitic coal abounds in the west), are not now known in 

 a scientific form ; and therefore science can give no help to pi- 

 Nothing but the union of the parties interested in coal-working can 

 furnish the data necessary for the establishment of general 

 [COAL-FOHMATIOX.] 



The beneficial results which mining operations have derive.! fi - n 

 geology ore in proportion to the degree in which the experience of 

 miners has been reduced to the form of science. On the subj 

 the situation of metallic treasures, already enough is known to show 

 that the occurrence of mineral veins is a circumstance de.pendiu:; ..-i 

 conditions which are more or less ascertainable. For example. 

 is not, and perhaps has never been, in tho British Isles, a single mine 

 of any metal worked in any stratum more recent than the 111:1.1: 

 limestone ; it is a general truth that rich veins of lead, copper, tin, 

 &c., abound only in and near to districts which have been greatly 

 shaken by subterranean movement; in Derbyshire, Alston Moor, 

 Flintshire, and, in particular tracts, especially Cornwall and IK-von, 

 it is very apparent that near the great masses of granitic rod. 

 veins are most richly filled. The some facts are almost-eqnally true 

 on the continent of Europe, and in other parts of the world, though, 

 occasionally, as in the Pyrenees, Auvergne, Ac., tin- pie-eiice of 

 igneous rocks may cause the exhibition of mineral veins in strata moru 

 recent than any of those which in England yield metallic ores. 



In all cases where new mining ground is to be attempted, rules 

 such as those above noticed are valuable; but even in ill 

 partially known, or long worked, many problems ocrur which time 

 and combined registration of phenomena observed might easily solve. 

 These geological problems, as to the relation between the cont 

 a vein and tho nature of the neighbouring rock, the occunvin < ( 

 certain cross-veins, tho depth of the workings, tea., usually , 

 themselves to tho practical miner under the general question of tlio 

 probability of the vein being productive, and though the mining 

 experience of 2000 years has been found insufficient to answer i', 

 there appears no reason to doubt that it is capable of solution by tho 

 progress of geology. It is known that in a country of limestone, 

 gritstone, and shale, equally broken by the same fissures, the former 

 is generally most productive of lead (Alston Moor) ; that 

 porphyritic rocks in Cornwall and Saxony ap|>ear directly influential 

 on the deposits of particular metals ; that argentiferous lead < 

 more frequent in primary than in secondary strata; wilts of ],M,| 

 more plentiful in the upper parts of veins (Lead Hill*. Caldbcck 

 Fells) ; but the precise nature of the connection of the phenomena is 

 yet a desideratum, and it will bo long ere the dim and wavering light of 

 | experience can be replaced by the steady beams of the toreh of 

 i science. In the recent discoveries of gold in California and A< 

 ' we have an instance in which geological knowledge pointed ."' 

 fully to these districts as being likely to contain the precious, metal. 

 [MINKH.U. VKINS.] 



In planning the lines of railways, canals, or common roado, the. 

 engineer will often be benefited by the records of geological sir 

 In looking at the geological map of England, for example, it must be 

 evident to any one acquainted with the geographical of the 



different formations, that no canal can be mode from London t 

 western or north-western counties without a tunnel or summit level 

 on the chalk hills (as at the Kennct and Avon, between Wilton and 

 -. and on the Oran 1 .luuetic.n, at Tring). The oolitic range of 

 bills, with its basis of lias, presents a similar and parallel obstacle, 

 c..ni|iirn:d by tunnels on the Thames and Severn at Shepperton, 

 the Oxford Canal at Claydon, the Grand Junction at Braunston and 

 Blisworth. 



Si then these and other ranges of hills compel the formation of 



summit-, .evels and tunnel*, it is of importance that the whole of a 



