INDEX. 



151 



Terraces, their position in respect to drift, 49. 

 Terraces, successive, produced by the same causes 



modified, 50. 

 Terraces mostly formed from drift, 50. 

 Terraces, the highest, 50. 

 Terraces, their number, height and breadth vary 



with the size of the river, 51. 

 Terraces, tabular view of their heights, 76. 

 Terraces, rarely correspond exactly on opposite 



sides of a river, 51. 

 Terraces slope usually as much as the stream does, 



51. 

 Terraces, highest usually about gorges, 52. 

 Terraces, water the chief agent in forming, 52. 

 Terraces, moraine, could not be formed by water 



alone, 53. 

 Terraces, moraine, how formed, 60. 

 Terraces, moraine, name unsatisfactory, 61. 

 Terraces, delta, how produced, 56. 

 Terraces, lateral, three modes in which they might 



have been formed, 5T. 

 Terraces, glacis, how formed, 58. 

 Terraces, gorge, how formed, 58. 

 Terraces, not formed by the bursting of barriers, 



59. 

 Terraces, not formed by paroxysmal vertical move- 

 ments of the land, 58. 

 Terraces, lake, how formed, 61. 

 Terraces and beaches formed at a period immensely 



remote, 63. 

 Thompson, Rev. Mr., his account of gorges on 



the river Jordan, 122. 

 Thompson, Professor, discovered the Delphinus 



Vermontanus, 65. 

 Trap Ranges in the Ct. valley, breached by several 



streams, 18. 

 Trigonometric survey in Massachusetts, 2T. 

 Tunnel of Hoosac mountain, begun, 141. 



IT. 



United States Armory, at Springfield, its geologi- 

 cal position, 15. 



V. 



Vermont, liberality of its citizens towards science, 

 102. 



Vertical movements of continents not generally 

 paroxysmal, 55, 58. 



Via Mala, gorge of, 11?. 



Volcanic Islands of the Pacific, gorges in, describ- 

 ed by Prof. J. D. Dana, 122. 



W. 



Wady el Jeib, in Palestine, 118. 



Wady Barida, in Anti-Lebanon, 118. 



Wales, marine shells in gravel on its mountains, 

 65. 



Wales, North, its surface geology, 34. 



Wantastoquit, or West river Mt., near Brattle- 

 borough, 99. 



Washington, Mount, N. H., not covered by the 

 drift agency, 55. 



Water, how high it has stood over this continent 

 since the tertiary period, 53. 



Water, as an agent of erosion, 83. 



Wells river, in Vermont, 26. 



West river Mt., or Wantastoquit, 2. 



Westfield river, 20. 



Western Railroad, its summit, 27. 



Westfield, or Agawam river, supposed marks of 

 ancient glaciers upon, 138. 



Whetstone brook, in Brattleborough, 22. 



White river Junction, Vt., 26. 



Whittlesey, Charles, on lake ridges, 44. 



Whittlesey, Charles, on western surface geology, 

 31. 



Whitney and Foster, their Report on the Lake 

 Superior Land District, 31. 



Wye, character of its banks, 35. 



Y. 



Yuba river, in California, gorge on, 10T. 



Zaire river, in Africa, erosion upon, 108. 

 Zug, lake, in Switzerland, 40. 

 Zurich, lake, in Switzerland, terraces and beaches 

 around, 39. 



