ON THE KENTISH BORING EXPLORATION. 381 



carboniferous limestone proper ; 3rdly, coal-measures. Whenever one of 

 these occurs the others follow, excepting where, as in places, the coal- 

 measures may have been denuded off, or where this may have happened 

 to the mountain-limestone also. 



The angle which the Devonian strata at Tottenham make with the 

 vertical bore-hole being 30°, it is to be inferred that their general direc- 

 tion there is east and west. 



The highly inclined position of these Devonian beds was important. 

 Had it been otherwise — had the beds there been found to be lying 

 horizontally — the prospect would not have been encouraging ; the two 

 members of the series above the Devonian might be supposed to have 

 been denuded off, or to follow in sequence only at some distance 

 horizontally. 



The upper Palasozoic group was not disturbed as we now find it till 

 after the completion of the coal-measures. This holds good from West- 

 phalia, across Belgium, and the North of France, and again in the west 

 of our British area. The preservation of available coal-measures along 

 this line is dependent on their having been enclosed in deep troughs, the 

 results of that east and west linear system of foldings and crumplings to 

 which the whole of this group was subjected. Hence it is that a Devonian 

 limestone reached in the course of such east and west line, and at a high 

 angle (30°), implies, first, that the said band of disturbed, strata passes 

 along at that spot, and next that the order of sequence is pretty sure to 

 be regular and complete there. In other words, the Devonian beds come 

 down upon at the Tottenham boring may be safely taken as a continu- 

 ation of the band which crosses Belgium and the North of France, and are 

 followed as the band is there by the mountain-limestone and coal-measure 

 series in a deep east and west fold or trough. 



One more point remains to be ascertained — What is the direction 

 of the dip of the Devonian beds of Tottenham boring ? and then any 

 one of the numerous sections which the Belgian and French geologists 

 have given of their coal- measure band may be taken as a guide as to what 

 has happened here ; of these, that of the Boulonnais is the best, because 

 nearest. Supposing that it could have been ascertained with perfect 

 certainty that the iuclined beds at Tottenham were dipping north, the in- 

 ference would be that there they had come down on the southern side 

 of a Palasozoic trough, and that the mountain-limestone series would follow 

 next. The thickness of this series in the Boulonnais may be taken at about 

 400 feet ; and the coal-measure-band would come in at about a quarter of 

 a mile or less from the corner of Oxford Street. 



On the contrary, had the dip been southerly, then the productive coal- 

 band would occur between Oxford Street and the Thames. 



It has been already stated that a single point remains to be ascertained, 

 and the object of the present communication is to show how and where 

 that is to be sought for. First, there must be another boring, and next it 

 must be so near to that at Messrs. Meux's that one may illustrate the 

 other, and so show the dimensions and positions of the Palasozoic bands 

 beneath London ; for this purpose the distance from Oxford Street ought 

 not to be more than a quarter of a mile to the north or south. 



The Tottenham boring properly considei'ed suggests that the Franco- 

 Belgian Palasozoic band with which coal is associated is continued under 

 London, and is within the narrow limits assigned above. Should such 

 be really the case, it is not supposed that in any such position it could be 



