PHYSICAL GEOGRAPHY OF THE COUNTY. F\ 23 



tions of Blair, Huntingdon, Mifflin, and Juniata counties 

 before entering Perry county around the east end of Tus- 

 carora mountain, 2 miles above Millerstown. 



It Hows nearly straight across the county (past the west 

 end of Buffalo mountain) 5 miles to Newport. It then 

 makes a letter S (3J miles) to Bailysburg ; followed by a 

 bend to the south, through the little gap of Half Falls 

 mountain, 1^ miles ; and then flows straight 5 miles further 

 to the Susquehanna river junction. 



From Mmerstown to the Aqueduct, measured along the 

 track of the Pennsylvania railroad, the distance is 15 miles ; 

 and the total descent of the railroad grade in this distance 

 is 31 feet ; an averege rate of about 2 feet to the mile ; 

 thus: — 



Millerstown, (138 miles from Philadelphia,) 408' A. T.* 



Newport, (133 " ) 395' 



Baily's, (128 " ) 387' 



Aqueduct, (123 " ) 377' 



The old levels of the Juniata division of the Pennsylva- 

 nia canal fniakes the water-fall 30.6 feet; the surface of 

 the Millerstown dam being stated at 388' and the miter-sill 

 at the Junction 357. 3'. But as the water above the lock at 

 the Junction is 370. 35', and the water in the Juniata river 

 under the aqueduct, stood at 342.6 when the survey of 

 1877 was made, J (or 340.6 by another survey, §) the actual 

 fall of the bed of the river is probably something more 

 than 31 feet. 



The rate of descent must be much more uniform than in the 

 case of the Susquehanna river, because the Juniata river passes 

 through only two gaps in.hard rock, and these are very small, 

 viz: one through the limestone-sandstone range at Mil- 

 lerstown, and the other through the same range at Baileys- 

 burg. Everywhere else it traverses broad belts of compara- 

 tively soft strata. The influence of the geology upon a river 

 course is however as well exemplified in the case of the Juni- 

 ata as in that of the Susquehanna ; for the sigmoid curve 

 which the Juniata makes between Newport and Bailysburg 



*See Report of Progress N, table 1, page 3. f See table 113, page N, 119. 



\ Table 115, page N, 121. § Table 125, page N, 136. 



