BIG SPRING PRAIRIE. 



CUMATIC CONDITIONS. 



Big Spring Prairie is crossed at two points by the 

 forty-first parallel, which forms the boundary line 

 between Wyandot and Seneca counties. By reference 

 to Map 1, it will be seen that almost equal parts of this 

 prairie lie on either side of this line. It is about forty 

 miles south from Lake Erie and about twenty miles 

 north from the Ohio River and Lake Erie divide. The 

 extremes of temperature are slightly greater here than 

 directly along the lake shore. This, in part, may ac- 

 count for some of the differences in vegetation of the 

 Big Spring Prairie and the Castalia Prairie near Lake 

 Erie. In the Spring, the vegetation which has begun 

 active growth during a few premature warm days, is 

 more likely to be injured by frost than the more tardy 

 vegetative growth of the lake region. In the Autumn, 

 frosts occur earlier than in the lake region. P'urther- 

 more, on the low lying prairie with its moist black soil, 

 frosts occur later in Spring and earlier in Autumn than 

 on the ridges around it. 



1. Physiographic. — Geological Formations 

 Surrounding Prairie and Characteristic Vege- 

 tation of Same. 



The Niagara Limestone is the native rock which 

 underlies the western part of Wyandot and Seneca 

 counties and the eastern part of Hancock county. 

 The surface of these counties is quite level, moderate 

 hills occurring only along the larger natural water 

 courses. As there are no important natural water 

 courses in the vicinity of the Prairie, the country is a 

 rather level plain with the exception of an interesting 

 and remarkable outcrop of Niagara Limestone. This 



