412 GEOLOGY OF CENTRAL WISCONSIN. 



Tlie parenthetical numbers of the detailed descriptions of this re- 

 port are those of specimens representing the rocks described. These 

 specimens will be distributed, according to law, to different institu- 

 tions in the state, and will be much more valuable for being cited here. 



It remains to make acknowledgments for aid received in the pros- 

 ecution of the field work, and in the preparation of this report. 



Mr. E. T. Sweet, M. S., a graduate of the State University, aided 

 me in the field work throughout the season of ISTi, and during much 

 of that of 1875. Several of the towns in Dane county were mapped 

 wholly by him, besides which he made many independent observations 

 in other jjarts of Dane county, and in southeastern Columbia county 

 Mr. Sweet also aided greatly in the chemical woi'k, having been thus 

 employed especially during the winter of 1875-6. With very few ex- 

 ceptions all of the analyses given in this report are Mr. Sweet's work, 

 and full credit is given him here for them. 



The late James IT. Eaton, Professor of Chemistry and Mineralogy 

 at Eeloit College, aided me in the field work during about two mouths 

 in each season, his services being given for his expenses only. His 

 faithful observations, more especially with regard to the Glacial Drift, 

 have contributed much to the material of this report. It is no exag- 

 geration to say that in Professor Eaton's death the state has lost the 

 best trained and most accomplished, and at the same time one of the 

 most conscientious and painstaking of its scientists. 



In the latter part of 1875, Mr. G. C. Synon, B. S., was my aid in 

 the field work. Messrs. Oliver Matthews and W. A. Hover, of the 

 Metallurgical Department of the State University, have both given 

 aid gratuitously in field work, and in making analyses. Analytical 

 determinations have also been made gratuitously by Mr. A. 0. Pres- 

 cott, in the University laboratory. Messrs. J. P. Paine, A. D. Con- 

 over, and P. L. Norman have aided me in preparing the cuts and 

 plates for this report. Mr. W. H. Canfield, of Baraboo, for many 

 years a surveyor in Sauk county, furnished me with a map of that 

 county, on which he had marked, from personal observation, the loca- 

 tion of quartzite outcrops, thus greatly lessening my own labor. I 

 should also add that Mr. Canfield's topographical map of Sauk county 

 has been of great assistance in outlining the formations. The citizens 

 of the region generally have aided me greatly. 



This report has been nearly all prepared, including illustrations, 



and the examination of between two and three thousand specimens, 



during the year ending June 1, 1877, for the most part whilst engaged 



in teaching several hours a day ; and the task has not been a light one. 



Uhtvbrsitt of Wisconsin, June 2, 1811. E. D. I. 



