45 



The same kinds of splits and fractures are seen throughout En- 

 gland, Scotland and Ireland, and have broken the great sedi- 

 mentary beds into various fragments of a somewhat rhomboidal 

 form, according to the oblique angles of the splits. (Plate IX.) 



On the continent of Europe similar series have been observed, 

 especially in Tangiers, Spain, France, Germany, Hungary and 

 Sweden ; we need not detail them, but beg reference to works 

 describing each district. 



These splits and fractures, and their being in continual motion 

 by the constant action of the polar force, produce great disorder 

 in the general structure, and cause dislocations in the order of 

 the masses (called heaves by the miners). These are the effects 

 of the horizontal or diagonal motion of the individual strips of 

 rocks between the splits from their original position. The great 

 heaves are produced by the northward action of the rocks be- 

 tween the polar splits ; the slides observed in the east and west 

 fractures are few, and generally insignificant ; they are the effect 

 of wedges of rocks squeezed between great splits. (Plate X.) 



These dislocations have created great discussions, and have 

 caused very opposite opinions, owing principally to the impossi- 

 bility of restoring the continuity of all the fractures on both 

 sides of the splits. A very little reflection must show that such 

 an agreement in all the fractures could not be expected. In the 

 first place, the ruptures across the splits would necessarily take 

 place in the direction of the least resistance, be that in a direct 

 line or not ; it does not follow that it should be straight across 

 the split. If, again, we consider that the rocks are exposed to 

 the continual action of the polar current, and therefore subject 

 to a slow movement northward, there would necessarily be frac- 

 tures taking place periodically in the same masses, i. e. when the 

 " heaves " are only 1, 10, 20, 30, 50 feet ; how then would it be 

 possible to restore the continuity of the whole series of fractures ? 

 It is well known, and can be proved, that the fractures have 

 occurred at different periods. It is like attempting to refit pieces 

 of ice, after having been broken and subjected to repeated move- 

 ments and reunited again by repeated freezing, as to try to re- 

 store dislocated masses of rocks in the primary base. 



When we consider the semifluid nature of the masses, and their 

 permitting a continual molecular action through their pores in the 



