1 o foiirnal of Travel and Natural History 



tional. Those who have not the leisure or the faculty for such a 

 kind of investigation will find the results of it in such detailed 

 maps as those of the Geological Survey. They will there observe 

 that the valleys much oftener cross faults than run along them; 

 and that while some lines of valley seem to have had their trend 

 determined by the direction of a powerful dislocation, many of the 

 largest faults are not marked at the surface by any line of depres- 

 sion, while most of the valleys cross and re-cross faults in all direc- 

 tions, and with such complete indifference, as to shew that their 

 courses have not been prescribed for them by lines of fissure in 

 the solid framework of the country. 



Between those valleys which have been determined by lines of 

 fault and those where this guiding influence has been wanting, 

 there are some strong points of difference. The former are, as a 

 rule, narrow in proportion to their length, deep, with a marked 

 monotony of breadth, and, instead of winding about, pursue a 

 straight line. The latter, on the other hand, wind along in wide 

 curves or short loops, now narrow with steep sides, now expand- 

 ing into a broad plain, and receiving sinuous tributaries like them- 

 selves. The second class will at once be recognised as the pre- 

 vailing type of valley in this country. 



But, apart from geological evidence altogether, the thought- 

 ful contemplation of a good map of the country seems to me 

 enough to suggest that the grouping of the valleys can hardly 

 be due to any cause acting from below. The endless branch- 

 ings and windings of the valleys, their herring-bone arrange- 

 ment, or, in other words, the way in which the runnels are 

 directed downwards into the streamlet, the streamlets into 

 the brook, the brooks into the river-course, the river-courses 

 into the wider valley that carries the water finally to the sea; 

 and then the wonderful harmony between the trend of the 

 valleys and their great function of carrying off the drainage of 

 the land are surely inexplicable on the supposition that these 

 features have been determined by systems of fractures in the 

 crust of the earth. Tl\e valleys have been specially adjusted for 

 carrying off the surplus water to the sea, and this accurate and 

 special adjustment could only have been the work of some force 

 acting on the surface, and necessitating the formation of the valley 

 systems in accordance with the drainage of the country. But the 

 only force which could do this is the flow of the drainage 

 itself, with all its attendant jihenomena of waste and removal. 



