ANNUAL REPORT FOR 1874. 49 



vice was exhausted in September. Some work had previously been 

 done near Madison. The services of Mr. E. T. Sweet were again se- 

 cured, and proved to be altogether satisfactory. On the 26th of June 

 the party had reached Lodi, and soon after, Portage, where Prof. 

 James II. Eaton, of Beloit, joined it in the explorations of the quartz- 

 ites of Columbia county. He continued with the party until near the 

 close of the season. At Grand Rapids the party ha4 an interview with 

 Prof. Davenport Fisher, of the ISFaval School at Annapolis, who had 

 made and furnished to the survey an analysis of the kaolin of that 

 place. In September Prof. Irving and Mr. Strong met in Jackson 

 county, and by conference, were enabled to determine some results 

 beneficial to the survey. 



Reference to the report of Prof. Irving, herewith submitted, will 

 show the progress he has made, and the results, so far as they havo 

 been worked up, at the present time. In this report will be found 

 much detailed information of local interest and importance, regarding 

 the dip, thickness and economic value of the several rocks, and its 

 publication cannot but be useful to the citizens of the state as well as 

 to the scientific geologist. With the aid of the map and sections, all 

 these details may be clearly understood, even by persons not familiar 

 with the science of geology generally. 



The interesting fact is pointed out that the boundaries of the prai- 

 ries, as laid down upon the government plats, correspond, in a gene- 

 ral way, with the boundaries of the geological formations another 

 instance of the bearing one study may have upon another. The na- 

 ture of the soil, derived directly from the rocks, has much to do with 

 the distribution of trees and other plants over the earth's surface, and 

 hence we find the native flora considerably modified by the rocks of 

 the several geological districts. 



The artesian well at the state house, Madison, disclosed the Arch- 

 aean character of the rock immediately below the Potsdam at that 

 place, and gives probability to the suggestion that our whole state is 

 underlaid by these rocks at no great depth. 

 Wis. SUB. 4 



- . ,> ii A Li Y 



UNIVERSITY OF 



CALIFORNIA. 



