372 Mr. P. J. Martin on the Anticlinal Line of 



Unfortunately for the progress of theoretical geology, it is 

 constantly being given up to the domination of a prevailing opi- 

 nion. I think I speak the sentiments of many faithful observers, 

 and men whose ambition it is to be thought good practical geo- 

 logists, when I say, that the persevering attempts that have been 

 made (doubtless actuated by the firmest convictions) for the last 

 twenty years, to reduce all theoretical notions of surface-changes 

 to one standard, and that the lowest of constantly existing agen- 

 cies, have been carried too far ; and that however necessaiy it 

 might have been in the infancy of the science to clip the wings 

 and curb the fancy of its votaries, extreme caution has overdone 

 its work ; and that it is become necessary, if we are to make any 

 great advances toward a more perfect knowledge of the nature 

 of these and some other phienomena that pertain to geological 

 dynamics, to return, in part at least, to the doctrines that held 

 sway some quarter of a centmy ago ; to reinvoke the assistance 

 of some long-neglected agencies, and familiarize ourselves with 

 scenes of greater activity than the uniform causation of the pre- 

 sent times will afford. The transporting power of icebergs, the 

 glacial abrasion of rock surfaces, the accumulation of moraines, 

 and the " oser " banks of the Scandinavian peninsula have had 

 their share of attention. But the subject of denudation, in its 

 larger sense, has long been held in abeyance. Whether it is 

 that the magnitude of the fields it embraces, or its inexplicable 

 confusion, deters men from entering into the investigation of its 

 causes, the fact is unquestionable, that whilst everybody is 

 speaking of it, or recording instances of its operation on the 

 scenes they describe, nobody makes any attempt to trace these 

 effects to their causes. Or if any such attempt is made, they 

 are carelessly referred to the feeble agencies with which we are 

 surrounded, without due consideration of their adequacy, or the 

 propriety of their application. For in many cases, as for instance 

 in such phaenomena as have been lately descanted on by Sir 

 Roderick Murchison in his lectures on the alpine regions of 

 Savoy, agencies have been invoked, which, as he shows, could 

 not have effected the purposes assigned them, in all time ; agen- 

 cies, in fact, which are no agents at all, inapplicable, and to appeal 

 to which is to fall into the " vulgar error '' of non causa pro 

 causa. Put the case, as of the gradual elevation of the Wealden, 

 and the quiet removal of the materials into the adjoining basins ; 

 — then, where are the beaches that should attest such gradual 

 elevations and gentle retirement of the sea, from the newly- 

 elevated lands ? Again, could we imagine the extensive excava- 

 tions under review effected by the slow operation of sea-currents 

 at the bottom of an ocean, be it shallow or profound ; — then, 

 whence the smashings and poundings of such mountains of an- 



