Davis — Terraces of the Westfield River ^ Mass. 83 



the most competent fashion swept away all the drift that could 

 be reached. It was only upon encountering the stubborn 

 resistance of an ambushed and impregnable ledge that the 

 river first withdrew, and even then it withdrew^ only to renew 

 the attack by returning bravely toward the spur on a later 

 swing. Unfortunately for the reputation of the river, the 

 ambushed ledges have been found entrenched farther and 

 farther forward at every successive attack that has been made 

 upon them ; hence the river, losing ground at every advance, 

 has come to be looked upon as a w^eakened and shrinking 

 stream that voluntarily abandons its earlier enterprises and 

 accepts a narrower limit for its conquests to-day than wdien in 

 a youth of (imagined) greater vigor and aggression ; but this is 

 a most unjust interpretation of its behavior. The river is 

 making a most determined and heroic effort to carry out its 

 original plan of campaign. It is eminently successful in open- 

 ing the valley east of Westfield, and if it is defeated at the 

 spur, this is only because of the reinforcement of the uncon- 

 solidated drift by the invincible strength of the entrenched 

 ledges. Tlie river may be accused of want of foresight in not 

 more carefully reconnoitering the ground that it originally 

 proposed to excavate, but it is notorious that rivers are heedless 

 of buried ledges, on which they often become inextricably 

 superposed. The river may be thought headstrong to return 

 to an attack, a forlorn hope, where defeat is inevitable. Heed- 

 less and headstrong it may be, but it does not deserve the 

 reproach of being looked upon as enfeebled. Even if its 

 volume is nowMess than formerly, the river is as competent 

 to-day as it ever was to open a wide flood plain in drift, and it 

 does so wherever free opportunity is offered of carrying out its 

 original enterprise. 



T. Relation of ledges^ tey^races and river svnngs. — It should 

 be noted that the ledges of the Westfield spur have not in any 

 case determined the depth to which the river has cut its valley. 

 The ledges here were not encountered in the river bed but in 

 the river bank, and hence have controlled only the breadth of 

 lateral swinging at the point where they were by chance dis- 

 covered. The depth at which the ledges were encountered was 

 dependent simply on the amount of valley excavation that had 

 been accomplished by the graded river at the time that the 

 discovery was made. It is also important to note that while a 

 ledge thus encountered in the bank of a swinging river will 

 defend and preserve that part of any flood plain previously 

 formed at a higher level, above and back of the ledge, it is 

 not at all necessary that every former flood plain of the river 

 should be thus recorded. If the successive northward swings 

 of an east-flowing river have by chance less and less ampli- 



