172 GEOLOGICAIv SURVEY OF NEW JERSEY. 



less favorable winter climate, and would produce a desert of 

 drifting sand, which would be shunned by all. There is no 

 difficulty in noting present differences of climate in winter 

 between the cleared and forested portions of Southern New 

 Jersey, and probably these differences are of a nature which affects 

 bodily comfort more than the records of the thermometer, as 

 they are largely due to the wind and moisture in the air. We 

 cannot doubt that if this sandy soil should be deprived of forest 

 cover it would quickly lose all vegetable matter, and would 

 become extremely hot in summer. We refer especially to 

 those portions which consist of silicious sands and are unadapted 

 for cultivation. 



The point may be raised that while the figures of annual 

 and average rain-fall show nothing as to the effect of forests, 

 there may be a difference of distribution, so that the fluc- 

 tuations may be greater and the droughts more severe in a 

 forested country. Of this we can find no evidence in the New 

 Jersey weather records. A careful study of these records indi- 

 cates that all parts of the State, whether forested or deforested, 

 are about equally subject to periods of drought, and that the 

 severity of the droughts, as measured by the rain-fall during the 

 dry period, varies with the average rain-fall, or, in other words, 

 those parts of the State which are shown on oiir charts to have 

 a large average rain-fall have a correspondingly larger dry- 

 period rain-fall. The severity of the drought as measured by 

 its effect on vegetation, however, is greater in those portions of 

 the State where temperature and, consequently, evaporation are 

 greater. Thus the Highlands and Kittatinny valley do not 

 suffer so severely from drought as the more southern portions of 

 the State, principally because evaporation is less. 



Unquestionably, forests have a marked effect in retarding the 

 melting of snow in the spring, and on this account it is possible 

 that owing to their presence the spring will be somewhat later 

 and cooler in a forested country than in the open. 



