ANNIVERSARY ADDRESS OF THE PRESIDENT. xli 



(jenei-al cause has been combined with more local causes to produce 

 our hues of elevation ; and according as N or n preponderate, we 

 must consider some general or some more local causes to be those to 

 which the phsenomena are attributable. 



If N be much greater than n, as we first supposed, the theory 

 which asserts that the parallel lines of the same system are of con- 

 temporaneous origin may be considered to be so far established, that 

 we may by induction apply it to determine the ages of the lines in 

 group ra, of whose age there is no direct conclusive evidence. The 

 final proof of the truth of the whole theory must then be sought in the 

 degree of harmony which peryades it, and the satisfactory manner in 

 which it may account for the general phsenomena of elevation. 



1 have been the more careful in directing your attention to these 

 points, because unless a marked distinction be made between those 

 cases in which the epoch of formation is determined on satisfactory 

 evidence, and those in which the evidence is inconclusive, a very 

 erroneous estimate might be formed of the real amount of evidence 

 in favour of this part of M. de Beaumont's theory. 



After having explained the general principles of this first part of his 

 theory, our author proceeds to describe the different parallel systems 

 which, as he conceives, our present knowledge enables us to recognize. 

 Much the greater number are founded on observations made in Eu- 

 rope, and are called European Systems, though their extension to 

 other quarters of the globe is regarded as probable. They are 

 twenty-one in number ; their names are derived from the foUovsdng 

 places : — 



La Vendee, 



Finisterre (Britanny), 



Longmynd, 



Morbihan (Britanny), 



Hundsriick and "Westmoreland, 



The Ballons (Alsace), 



Forez (Department of the Loire), 



North of England, 



The Netherlands and South Wales, 



The Rhine, 



Thuringerwald, 



The Cote d'Or, 



Vercors* (Department of La Drome), 



Mont Viso (French Alps) and Pindus, 



The Pyrenees, • 



Corsica and Sardinia, 



Tatra (N. of Hungary), 



Sancerrois (France), 



The Western Alps, 



The principal Chain of the Alps, 



Tenara (Prom, of Tanarium, Peloponnesus). 

 These systems are described, and the evidence on which they rest 

 is given in considerable detail in M. E. de Beaumont's work. 



* The relative age of this system is not determined. 



