228 APPENDIX. 



the deep shadows cast by the high, steep bank and its over- 

 hanging vegetation, forms a pleasing rehef to the glare, so 

 uniformly fatiguing, of the unsheltered prairie. This spot 

 conveyed so much relief to the eye and to the mind, that the 

 party could not repress their delight on beholding it. The 

 geologist who connects a change in the nature of the subja- 

 cent rock, with a diversity in the character of the country, or 

 its vegetation, would naturally find an explanation for the* 

 new features which the country assumes, by observing that 

 the high banks of this glen are formed of sandstone rocks, 

 the nature of which we had an opportunity of studying with 

 attention during a great part of our journey of the 18th of 

 June. We obsen^ed that the sandstone is distinctly super- 

 posed to the limestone ; that it constitutes, upon it, hills 

 which vary from 30 to 100 feet and upAvards ; these hills 

 are divided by valleys, in the bottom of which the limestone 

 reappears in place. The sides of the hills are steep, and but 

 few indications of stratification are observable, except where 

 the valley is partly excavated in the limestone itself ; in 

 which case the lower part of the hill is less steep, but pre- 

 sents a distinct stratification. The line of superposition of 

 the sandstone over the limestone may also be traced with 

 considerable accuracy, by the examination of the vegetation. 

 Whenever the latter rock prevails, the surface is even and 

 smooth, or modified by gentle swells covered with a thick 

 and long grass, and forming an uniform fine green, meadow- 

 like country, while the sandstone invariably imparts to tlie 

 surface an asperity which is as distinct as the vigorous growth 

 of trees with which it is covered, and as its abundant under- 

 growth which denotes a strong and productive soil, having a 

 tendency to bear heavy forests. 



geological facts of the author, and our readers are at liberty to differ in 

 matters of taste. 



