OF THE SEA AND LAND. 2S 



abuse : having been adopted even to explain the di- 

 rections and forms of mountains, consequent as these 

 are on the nature of the rocks, and the positions of the 

 strata. When all the ridges of the earth were supposed 

 to lie in one direction, it appeared simple, at least ; 

 though we may wonder at the hydraulic knowledge 

 which first produced these currents, and could then 

 assign the enormous destruction of solid rock to this 

 cause. In cases innumerable, no imaginable system of 

 oceanic currents could have produced the effects ; as, 

 in many more, there should have remained other traces 

 which do not exist : but as an examination of exam- 

 ples would lead to great length, such enquiries must be 

 trusted to those who are more willing to investigate 

 truth than to establish a theory, and who possess, at 

 the-same time, that geographical eye, and that accurate 

 and extensive geological knowledge, which are indis- 

 pensable in such cases. The vanity of explaining every 

 thing has ever been the bane of knowledge : while it 

 is seldom considered how often it is the proof of igno- 

 rance. He who knows much, has no fear of stating 

 what he does not know : whereas he who knows little, 

 pretends to every thing, because he knows not where 

 he may safely confess his ignorance. 



Because the excavation of valleys has been referred 

 to this cause, by geologists of such reputation as Saus- 

 sure, I must enquire of the matter, though the result 

 cannot be creditable, either to him or his followers ; 

 least of all to those of mathematical attainments. If 

 there are cases where the action of some such cause is 

 probable, its power has been often unwarrantably ex- 

 tended ; while, in many valleys, it could not have pro- 

 duced the required effects, or should have left other 

 traces. It is not unusual for many valleys to diverge 

 from one point, for two to separate in opposite dircc- 



