Sii^ H. H. Howorth — Geological History of the. Baltic. 359 



verticales sont, de nos jours plus, que clair semes et en dehors de 

 quelques rares attardes, personne n'oserent encore attribuer a une 

 telle action une part serieux dans la formations des montagnes " 

 (Bull. Soc. Geol. France, ser. iii, t. xv, p. 217). 



Again, the same graphic and lucid writer, speaking of what he 

 calls " impulsions verticales", says: "lis s'expliquent sans difficulte 

 si on les considere comme la production des movements generaux 

 d'une ecorce soumise a des efforts lateraux de compression, 

 developpees par la necessite ou elle se trouve de se plier aux 

 changements de dimension du noyau interne. De cette maniere 

 certaines parties se gonflent I'ocean, tandis que d'autres semblent 

 I'attirer dans les sillons qui vont se creusant de plus en plus " {Traite 

 de Geologie). 



It is assuredly by this process that the tectonic changes in the 

 earth which have diversified its surface into mountain and valley 

 have been in the main induced. It is equally plain that this process 

 of bending into undulations and curves cannot go on for ever with 

 such very tough materials as the earth's crust is largely formed of, 

 without a break. The tension must presently be so great that the 

 rocks will give way and split, and form huge rifts and crevasses and 

 raw scarps and cliffs. Scandinavia presents us with most admirable 

 evidence of the results of this crumbling process on a large scale in 

 producing the diversified features of the country : a great many of us 

 are witness to that. They meet us at every turn in the contortions 

 and folds made violently, and involving great breakages and gaping 

 wounds in the hardest crystalline rocks as well as in those of 

 Secondary age. The Alps, the Pyrenees, and the Himalayas give us 

 similar very notable samples from Tertiary times, of raw angular 

 tears and rifts, gullies and nullahs, and perpendicular scarps and 

 faults, as well as huge anticlinal and synclinal bends and overthrows. 

 !Mohn has picturesquely described the results in Norway. " The oldest 

 formations in Norway," he says, "are greatly bent, compressed, 

 and distorted, and their parts forcibly dislocated, alike as regards 

 situation and relative height. Formations that in the interior lie at 

 a height of several thousand feet are on the coast found level with 

 the surface of the sea ; strata resting on the summits bordering 

 a lake or the shores of a fjord are again seen on islands in such lakes 

 or fjords and level with the surface of the latter. One side of 

 a valley exhibits a profile which, in regard to the height of the 

 various strata, differs materially from the profile of the opposite side. 

 The whole rocky shore is cut up in various directions, and the several 

 laminae are now sunk beneath, now raised above, those adjoining 

 them. These dislocations have been caused by fissures, which in 

 many places can be pointed out, and the number of such recorded 

 faults of dislocation increases almost every year. The direction of 

 the fissures is manifestly of the greatest assistance in indicating the 

 form exhibited by the surface of the country. The subsidence 

 between two fissures produces a valley or fjord ; its rise, on the other 

 hand, a height or a promontory. Professor Kjerulf has succeeded in 

 showing that the entire system embracing the valleys and fjords of 

 Southern Norway may be easily referred to four principal directions 



