Chautauqua Grape Belt. 155 



due to a tilting of tlie land since the beaches were formed. There 

 is abundant evidence that the land is now and has been in the past 

 in a state of motion. Actual historic record proves tnis m several 

 places, and geological study proves it in many more. Since the 

 glacial period the movement in this part of the land has been that 

 of tilting, with greater elevation in the northeast. Therefore these 

 beaches do not show so great a change as they would if they 

 extended in a more nearly north and south direction. The amount 

 of tilting varies from place to place, but in the Chautauqua grape 

 belt averages not far from one foot per mile. 



A final question that we may ask, is how long ago this happened. 

 To this no definite answer can be returned. A study of Niagara 

 gorge, which has been formed since Lake Erie fell below the lowest 

 gravel ridge, seems to show a period between 4,000 and 15,000 

 years. There is some reason for believing that the first is nearer to 

 the truth than the last, and that it may even be a shorter period 

 than this. Otherwise it would be difficult to account for the fact 

 that these gravel ridges have resisted destruction so well. Nor can 

 we state any more definitely how long it took the lake waters to 

 build the beaches. They probably do not represent a great length 

 of time, for materials were apparentl}' rapidly supplied. 



Climatic Conditions. 



While the soil is a very important element in the value of ^ the 

 grape land, the climate is of even greater importance. Hence, 

 while this study was not made primarily with the object of deter- 

 mining the climatic peculiarities of the belt, some features of a 

 general nature were so pronounced that they attracted attention. 

 The lake is a great modifier of climate. In the spring, by reason, 

 of the low temperature of its waters, it holds back the vegetation 

 and this tends to keep it behind the ordinary frosts. Its very 

 presence checks frost by moderating the temperature of the neigh- 

 boring air. In the summer, the water tends to cool the air of the 

 day and to keep the nocturnal temperature fairly high. During 

 the fall, the water has been warmed by the summer sun, and the 

 influence of this warm body of water lengthens the growing season 

 and tends to keep off the early autumn frosts. 



There are many other influences, but nothing of importance 



