Septembkr 19, 1895] 



NATURE 



493 



feet, these being separated from the thick Jurassic beds (incUid- 

 ing therein the Liassic and Rha;tic) by perhaps 420 of Trias. 

 They consist of Coal Measures, which were pierced to the depth 

 of about 230 feet. 



In and near Northampton, north-eastward of the last site, and 

 still further from the northern edge of the London Basin, the 

 like occurs ; but the beds found are older than the Coal 

 Measures, and the Trias is thin, not reaching indeed to go feet 

 in thickness, and being absent in one case. -M one place, too, 

 the Carboniferous beds have been pierced through, with a thick- 

 ness of only 222 feet, when Old Red .Sandstone was found, and 

 in another place still older rock seems to have been foimd next 

 beneath the Trias. The depth to the rocks older than the Trias, 

 where they were reached, was 677, 738, and 790 feet, or re- 

 spectively 395, 460, and 316 below .sealevel. Some of the.se 

 figures must be taken as somewhat ajjproxiniate, though they 

 are near enough to the truth for practical purposes. 



A boring at Bletchley, to the south, reached granitic rocks at 

 the depths of 378.^ and 401 feet ; Init these rocks seem to be 

 only boulders in a Jurassic clay : their occurrence, however, is 

 suggestive of the presence of older rocks at the surface no great 

 way off, in Middle Juras-sic times. 



>Iuch further northwartl, at Scarle, south-west of Lincoln, 

 the older rocks have been reached at the depth of about 

 1500 feet, all but 141 of which are Trias, and they begin with 

 the Permian (which crops out some eighteen miles westward), 

 the Carboniferous occurring after another 400 feet, and having 

 been pierced to 130. 



We have then evidence that over a large part of south-eastern 

 England, reaching northward and westward of the London 

 Basin, though the older rocks are hidden by a thick mantle of 

 Jurassic, Cretaceous, and Tertiary beds, )et they seem to be 

 rarely at a depth that would be called very great by the coal- 

 miner. They are distinctly within workable depths wherever 

 they have been reached. 



There is no area of old rocks at the surface in our island, 

 south of the Forth, in which Coal Measures are not a constituent 

 formation. Truly, further north, in the great tract of Central 

 and Northern Scotland there arc no Carboniferous rocks ; but 

 we can hardly say that none ever occurred, at all events in the 

 more southern parts. We know, though, that on the west and 

 north Jurassic and Triassic beds rest <m formations older than 

 the Carboniferous. 



It is not, however, to this more northern and distant tract 

 that we should look for analogy to our underground jilain of old 

 rocks ; rather shoidd we look to more southern parts, to Wales 

 and to central ami muthern England, where Coal Measures are 

 of frequent occurrence. On the jjrinciple of reasoning from the 

 known to the unknown, I cannot see why we should expect any- 

 thing but a like occurrence of Coal Measures, in detached basins, 

 in our vast underground tract of old rocks. 



What, then, is the evident conclusion from what we know and 

 from what wc may reasonably infer ? Surely that trials should 

 be made to see if such hidden coal-basins can be found. 



One trial has been made, and it has succeeded ; the Dover 

 boring has jiroved the presence of coal imderground in Eastern 

 Kent, along the line between the coal-fields of .South Wales and 

 of Bristol on the west, and those of Northern France and of 

 Belgium on the east. 



The long gap betw'een the distant outcrops of the Coal 

 Measures near Bristol and Calais lias been lessened \ery slightly 

 by the working of coal ui\der the Triassic and Jurassic beds near 

 the former place, but nuich more by our Itrethren across the 

 narrow sea, the extent of the Coal Measures, beneath ihe Juras.sic 

 and Cretaceous beds, having not only been proved by the French 

 and the Belgians along their borders, but the coal having been 

 largely worked. At last, we too have still further decreased the 

 ','ap, by the Dover boring, a work that I trust is to be followed 

 y other work along the same line. 



But is this the only line along which wc are to search ? Are 

 we to conclude that the only coal-fields under our great tract of 

 Cretaceous beds (where these are either at the surface or covered 

 l^y Tertiary beds) are in Kent, Surrey, and other counties to the 

 west? Have we no coal-fields but those of Bristol and of South 

 Wales? The bounds of our midland and northern coal-fields 

 have been extended by exploration beneath the Ne«' Red Series ; 

 are we to stop here and to assume that there can be no further 

 underground extension of the Coal Measures south-eastward .-' 

 This seems har<lly a wise course, and is certainly a very unenter- 

 prising one. It seems to me rather that the riglit thing to be 



NO. I 35 I, VOL. 52] 



done is to try to find out the real state ol things, by means of 

 borings. 



There are, of course, objectors in this as in other matters. 

 Some may say that it is silly to try in Suffolk, and that Esse.\ 

 gives a better chance of success. Others, again, may prefer 

 Norfolk. And yet others may argue that there is no chance of 

 finding Coal Measures in any of those three counties. But I 

 must confess my inability to understand this line of reasoning ; 

 the fact is that the data we have are few and far between, and 

 that we want more. It is really of little use to bandy words, 

 and I do not now mean to take up the matter in <ietail. We 

 cannot get at the truth except by actual work ; justification by 

 faith will not hold in this case, .still less justification by unfaith. 



Let us hark back a little and call to mind w hat has happened 

 in the past. I remember the time when certain geologists 

 disbelieved in the possibility of the occurrence of Coal Measures 

 anywhere in south-eastern England, it being argued that the 

 formation thinned out before it could get so far eastward. Then 

 this view was somewhat varied, and it was inferred, from certain 

 observed facts, that even if Coal Measures did reach under- 

 ground into these benighted parts, they would be without work- 

 able coal, and so practically useless. 



Now for some years nothing occurred to upset the prophets 

 of evil, that is to say, no fact came to light. There were not 

 wanting inferences to the contrary, but it remained practically a 

 matter of opinion. One day, however, the needful fact came, 

 and the first boring made specially to test the question (at Dover) 

 disproved both the above negative theories by finding Coal 

 .Measures with workable coal. Let us hope that a like result 

 may happen in East Anglia, and that the pessimists may again 

 be in the wrong. 



We should not, however, fall into the opposite error, that of 

 optimism. We must not expect an immediate success like that 

 at Dover. We are here much further from any known coal- 

 field. Advertisements of various wares sometimes tell us that 

 " one trial will suffice," but it is not so in thisca.se. We should 

 not be content until many borings have been made, and we 

 should not be despondent if, after sites have been selected to the 

 best of our judgment, we begin with a set of borings that are 

 unsuccessful in finding coal. 



.\l the time of « riting I cannot .say that the Stutton boring is 

 a success or a failure as far as coal is concerned, but I am quite 

 ready to accept the latter without being discouraged. Whatever 

 it is you ma)' know during our meeting ; it is certainly a success 

 in the matter of reaching the old rocks at a depth of less than 

 1000 feet. We should remember thai every boring is almost 

 certain to give us some knowledge that may help in future 

 work. 



There is a further point, however, lb be taken into account. 

 A boring that may at first .seem to be a failure, from striking 

 beds older than the Coal Measures, may some day turn out 

 otherwise. The coal-field along the borders of France and 

 Belgium is sometimes aft'ected by powerful and peculiar dis- 

 turbances, by faults of comparatively gentle inclination (far 

 removed from the usual more or less vertical displacements) 

 which have thrown Coal Measures beneath older beils in large 

 tracts. This is no mere theor)-, though advanced as such at 

 first by .some continental geologists, who have had the great 

 satisfaction of seeing their theory adopted by practical men, and 

 proved to be true, much coal being w orked below the older beds 

 that have been pushed above the Coal Measures by the over- 

 thrust faults. 



Our trial-work, of course, does not yet lead us to consider 

 such disturbances as those alluded to. We have at first to 

 assume a normal succession of formations, and not to carry on 

 exjilorations in beds that can be proved to be older than the 

 Coal .Measures ; but the time may come when it will be other- 

 wise. 



Another matter to which attention has l)een drawn by our 

 foreign friends is an apparent general persistence of disturbances 

 along certain lines, or in other words, the recurrence of disturb- 

 ances in newer beds in those parts where earlier movements had 

 aflected older beds ; so that, reasoning backward, where we see 

 marked signs of disturbance for long distances in beds at or near 

 the surface, there we may expect to find pre-existing disturb- 

 ances of the older beds beneath. This, how ever, is a somewhat 

 controversial question, and much remains to be done on it ; but 

 shoidd it be proved as a general rule it may have much effect on 

 oiu' underground coal. 



Finally, the question of the possibility of finding and of work- 



