122 REVIEWS 



t 

 had the southerly slope been the same as now. For example, at the 

 Wells river, Vermont, the altitude of the river is now 407 feet above 

 tide; but anciently it was 356 feet. The highest terrace is now 630 

 feet; formerly it is estimated to have been 373 feet, a fall of 257 feet. 

 The reduction of the descent was from 2 to 1.4 feet to the mile. (3) 

 The carving of the greater terraces was effected while the land was 

 resuming its present level — probably lower than its original altitude. 

 (4) The lower terraces and the intervals were formed later. 



The following features were not clearly understood: (i) Why 

 should the terraces upon the opposite sides of the valley commonly 

 vary in numbers, altitude, and bulk ? (2) Why are the deltas of the 

 tributaries so often higher than the normal flood plain ? (3) Why 

 should the number of the terraces of the tributaries so often exceed those 

 of the main stream, their upper surfaces being the same ? These 

 queries may be answered partly by assuming that the flood plain was 

 not entirely filled out and that the tributary may often have had an 

 extraordinary volume, bringing down a disproportionate amount of 

 sediment. But there remained this problem : Why is there such a 

 great irregularity in the altitudes and number of the lower terraces? 



A better understanding of this subject has been afforded by the recent 

 paper of Professor W. M. Davis,' who applies to the solution of the prob- 

 lem the theory of Hugh Miller the younger. Miller recognizes a slow 

 regional uplift while the river wears away the accumulated sediment, 

 and ascribes the presence of each lower terrace to a species of protec- 

 tion afforded by such obstacles as ledges and till, as the degrading 

 river swings laterally to lower and lower levels. At the Westfield 

 locality the presence and altitude of every terrace are clearly shown to 

 be due to this cause. The simplicity of this explanation causes one to 

 wonder why it had not been understood earlier. I have applied it 

 extensively the past season to the modified drift of the upper Connecti- 

 cut and adjacent streams and found it very generally acceptable ; in 

 fact, its well nigh universal adaptation became quite monotonous. 

 Diagrams were prepared to showhow the terraces had been protected over 

 an area fifteen miles long in the neighborhood of White River Junction 

 and Hanover. The villages of Hartford, Wilder, and Hanover occupy 

 such protected situations. Between East Hartford and Wilder an esker 

 with underlying stiff clays has assisted in the preservation of the 

 ancient flood plain. In Haverhill, thirty miles northerly, the absence 



"^"The Terraces of the Westfield River, Massachusetts," American Journal of 

 Science, Vol. XIV (August, 1902). 



