CHAPTER IV. 



CLIMATE.* 



The climatology of the State can only be properly ascer- 

 tained from a careful comparison of a long series of 

 observations made at different points in various parts of 

 the State. Yet- much of great value, to the agriculturist and 

 others, may be learned from a study of the observations 

 made at a single point, and their value enhanced as they 

 extend over a longer period of time. The observations upon 

 which this chapter is based, prepared at the request of C. A. 

 White, M. D., State Geologist, to accompany his report upon 

 the Geology of the State, were made by the writer at Musca- 

 tine, (Bloomington, until 1837) and Iowa City, commencing 

 January, 1839, and continued until the present time. Those 

 at Bloomington, 1839-1847, were furnished the Government 

 through Prof. Espy, of the Treasury Department, until the 

 organization of the " Smithsonian Institution," where, at the 

 request of Prof. Henry, Secretary thereof, they were con- 

 tinued at Muscatine from 1847 to 1860 and at Iowa City from 

 1860 to 1869. The difference in latitude is about one-tenth 

 degrees, and longitude about five-tenths degrees. I have 

 calculated the means of the observations at Muscatine for 

 twenty years and at Iowa City for ten years, and find that 

 the difference is so very slight that I have not hesitated to 



* Professor Theodore S. Parvin, of the State University, has generously contributed 

 the entire contents of this chapter'— O. A. White. 



139 



