330 



PHYSICAL GEOGRAPHY. 



less swelling of the streams than is experienced farther south and in the 

 interior, where the depth of snpw is less, but where the spring heat comes 

 on more suddenly, and without the moderating influence of cold sea 

 winds. 



The effect of summer temperature, also, although sufficient to produce 

 the lowest run in our streams for the year, is yet far different from that 

 experienced in many portions of our country. No such thing is known 

 in New Hampshire as the drying up of streams, draining hundreds of 

 square miles of territory, into chains of half-stagnant pools, their beds 

 turned into wastes of fissured, sun-baked mud, strewn with the stumps 

 and driftwood of freshets, leaving long bridges stretching across dry 

 land, where, at the spring flood, a torrent twenty feet deep fills the entire 

 channel. 



In conclusion, it appears that the temperature of the state, on the 

 whole, influences very favorably both the volume and constancy of our 

 rivers. The mean for the year is comparatively low, and the loss from 

 evaporation is therefore of necessity comparatively small. Our relative 

 advantage in this respect is also greatest in the abatement of the drouth 

 of summer, which everywhere fixes the limit of the capacity of water- 

 power. 



Fig. 45. — OLD MAN OF THE MOUNTAINS. 



