399 



OF EXTENSIVE, BROAD, OR NARROW VALLIES, OR IN- 

 TERVALS. 



1st. Are they generally level, or broken and inter- 

 rupted ? If of the former kind, do they appear to be 

 composed in any degree of alluvion? This may be 

 determined by several means. 1st. By the nature of 

 the soil, being either of sand, or gravel, and differing 

 materially from that at the bases, and on the sides of 

 adjacent mountains. 2dly. By ditching, canaling, 

 sinking wells and other works, by which the structure 

 and character of the earth beneath the surface is ex- 

 posed to view. If composed of alternate layers of 

 sand, clay, and pebbles, in horizontal, inclined, or un- 

 dulating strata, with occasional deposites of fossil 

 wood, or organick remains, it may reasonably be consi- 

 dered as alluvial. If on the contrary, it is of an uni- 

 form texture, and presenting none of the above marks, 

 it may be considered as not having been disturbed, and 

 as original. 



2d. If the earth, thus exposed, appears stratafied 

 and horizontal, what is the order in which they occur, 

 and to what depth has this appearance been known to 

 extend ? 



3d. If the strata are inclined and undulating, or 

 ware-like, what is the dip or inclination of such strata, 

 and what the general direction of their dip ? 



4?th. If pebbles occur in such strata, are they in 

 aids, or nests like, or uniformly distributed to any 



