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believed that the still greater physical effects everywhere met 
with in the French and Belgian Coalfield, a few examples of 
which the writer would now endeavour to describe, will entirely, 
remove any scepticism which still exists. 
In the notes furnished by Dr. Hovelacque, he has given a 
series of sections across the coal basin at various points, from. 
near Calais, on the W., to Liege, on the E.; but, although these 
present endless variety in detail, their main features are every-: 
where more or less the same, so that a few typical examples will 
suffice. 
_ And in order, first of all, to explain the structure of the 
foundation rocks associated with the French and Belgian Coal- 
field, the writer would direct attention to an enlarged copy of a 
theoretical section of the country around Ardennes. 
From this it will be seen that, prior to the Devonian period, 
there must have been a great elevation of the older rocks, which. 
were thrown up into a series of parallel ridges, four of which 
appear in this section, ‘viz., the crests of Brabant and Condroz, 
consisting of Middle Silurian, and two other ridges, consisting 
of the Cambrian rocks. These appear to have been tilted up at: 
high angles by a great pressure from the S., and, within the: 
intervening valleys, the Devonian and Carboniferous rocks were 
successively deposited on the upturned edges of the older rocks. 
This section illustrates what has been pointed out in an earlier 
part of this paper, viz., that while on the N. side of the crest, 
of Condroz only the middle and upper Devonians are present, 
the upper, middle, and lower Devonians are all represented on 
the S. side of that axis, proving that the basin of Namur was 
not invaded by the sea during the lower Devonian period. 
Towards the close of the Carboniferous formation the entire 
range of the Continental field from Calais to Westphalia appears 
to have been the scene of great physical disturbances, the 
Devonian and Carboniferous rocks having been elevated by a 
great pressure from the §., and pushed forward towards the N. 
