752 ‘PROF. J. W. JUDD ON THE NATURE AND RELATIONS OF 
XII. Concrvston. 
These interesting discoveries at Richmond throw much new light 
upon some very important geological problems, among the chief of 
which we may particularize the following :-— 
A. The nature and position of the several rock-masses which 
constitute the great Paleozoic ridge underneath the London Basin, 
and the relations of the strata which haye been subsequently 
deposited to these deep-seated rock-masses. 
B. The question of the existence of deep-seated sources of 
water-supply in strata, older than the Chalk, under any portion of 
the metropolitan area. 
C. The possibility of finding coal-seams at a workable depth 
under London, and the quality of the coal to be obtained from such 
sources. 
We shall conclude this paper by a brief discussion of each of these 
problems. 
A. The Position and Nature of the “ Paleozoic Avis” and tts 
Relation to overlying Strata. 
The possible connexion of the Palzozoic axes of the Mendips 
and the Ardennes, and of the coal-fields which abut upon them, 
was suggested by Buckland and Conybeare in 1826, by MM. Elie de 
Beaumont aud Dufrénoy in 1841, by Sir H. de la Beche in 1846, 
and by M. Meugy in 1852. : 
The French and Belgian geologists had long ago practically 
demonstrated the existence of the eastern parts of this great connect- 
ing ridge by actually working coal under the Tertiary and Cretaceous 
strata. But in 1855, Mr. Godwin-Austen, in his celebrated paper 
‘< On the possible extension of Coal-bearing strata beneath the South- 
east of England,” gave to these arguments concerning the relations 
of the Paleozoic rocks to the Secondary strata a force and precision 
which they did not before possess. 
In the interval between the reading of Mr. Godwin-Austen’s 
paper and its publication in the Quarterly Journal of this Society, 
the completion of the experimental boring at Kentish Town went 
far towards verifying the predictions of geologists; and since that 
time a number of deep wells have made us acquainted with the 
nature and position of different members of the Paleozoic series 
under the Secondary rocks of England and of the adjoining portions 
of the Continent. 
Silurian strata have been reached at Ware at a depth of 796 ft. 
from the surface, and at Ostend at a depth of 985 ft. 
Devonian strata have been reached at Tottenham Court Road at 
a depth of 1064 ft., and at Turnford, near Cheshunt at a depth of 
980 ft. 
Carboniferous strata have been found at Burford in Oxfordshire 
at a depth of 1184 ft., at Gayton in Northamptonshire at a depth 
of 635 ft., at Northampton, in the same county, at a depth of $30 
