246 J. noPKiNSON — recent discovery of 



"Wc have, therefore, unrlor the London Basin, an axis of Palocozoic 

 rocks, two divisions of which have now been discovered, namely, 

 the Upper Silurian and the Devonian. This axis has been inferred 

 to be a prolongation eastwards of the Palajozoic ridge which skirts 

 the coal-basin of South \Yales, then forms the Mendip range, 

 disappears under Secondary rocks near Frome, and, after passing 

 under London and the south-east of England generally, is possibly, 

 under somewhat different conditions, the same ridge which is 

 known as the axis of the Ardennes. The rocks of which it is 

 composed are presumably, from their known character in their 

 prolongation east and west, much contorted, and within the folds of 

 the Devonian rocks it is possible there may be beds of coal, for 

 elsewhere Carboniferous strata, with productive coal-measures, 

 accompany them in their contortions, to the extent, as in the Auchy- 

 au-Bois coal-field, of actually underlying them ; the Devonian being 

 folded over the Carboniferous strata. The strike of the old rocks, 

 between London and the Mendip Hills, would according to this 

 view be due east and west. The fossils from the Silurian rocks 

 of the Ware boring are, however, typical of the Wenlock shale as 

 met Tvith at Dudley and Wenlock Edge, seeming to show that 

 the strike of the Silurian rocks at least is north-west and south- 

 east, in which case we may have coal-beds on the northern flanks 

 of this anticlinal, as well as on the southern in the synclinal 

 trough, or within folds in the Devonians, between this axis and 

 that of the Mendips and Ardennes to the south. The Ludlow 

 rocks might be expected to occur under Hertford ; and it would 

 then become an interesting question as to whether the next series, 

 occupying that part of the old land surface lying between Hertford 

 and Kentish Town, would be, as at Messrs. Meux & Co.'s boring, 

 marine Devonians of Devonshire and Cornwall type, or " Old Red" 

 beds similar to those which succeed the Ludlow rocks in Here- 

 fordshire. It appears more likely that a coal-basin would lie to 

 the south-west, if Old Eed Sandstone beds of estuarine or lacustrine 

 origin followed, than if the next series were of the marine 

 Devonshire type. 



The practical importance of this discovery at Ware thus seems to 

 lie mainly in the knowledge thereby gained of the direction towards 

 which any search for coal is most unlikely to be successful, for it is 

 now seen that it would be useless to search for coal (in the London 

 Basin) north of London. It would also appear that any search for 

 water-beariug strata below the Gault south of Ware, as far at 

 least as the River Thames, would be equally futile, Palfcozoic 

 strata here taking the place of the permeable beds of the Lower 

 Greensand and the underlying clays. The geological interest of the 

 discovery seems to be the knowledge of the old land-surface thus ob- 

 tained. A Silurian ridge is now revealed to us, on the southern flanks 

 of which repose Devonian rocks; against this old ridge on either side 

 beat the waves of the Cretaceous or pre-Cretaceous seas ; across the 

 northern portion of our present metropolis the old coast-line of the 

 southern sea is seen ; near our county town the old coast-line of 



