STATE GEOLQGIST. 25 



predict with considerable confidence the depth at which the 

 salt bearing rocks of Grand Rapids would be reached. The 

 subsequent result very happily justified my judgment, and we 

 are enabled to day to look upon one ©f the leading enterprises 

 of the State as the direct offspring of theoretical geology. 



Dr. Miles, after spending some time on the Flint and Saginaw 

 rivers, visited the numerous lakes and streams of Oakland, 

 Livingston, Genesee, Lapeer and Washtenaw counties, and to- 

 ward the close of the season paid a visit to the western part of 

 the State. He was accompanied during most of the season by 

 Mr. Dodge, of Flint, and for a few weeks by Dr. Jewell, of Ann 

 Arbor. While in the vicinity of Flushing, in Genesee ceunty, 

 he collected valuable observations and specimens from the 

 outcrop of theVjoal series; and these have been communicated, 

 with proper diagrams, to this department. 



In December, I entered upon a comparative examination of 

 Michigan and Ohio gypsum. A chemical analysis of each was 

 made, at my request, by Prof. L. R. Fisk, of the Agricultural 

 College; and at the instance of C. A. Trowbridge, Esq., of De- 

 troit, 1 drew up a paper on the subject, which was placed in his 

 hands. 



In the month of February, 1860, 1 paid a visit, by request, to 

 the salt works at Grand Rapids. I collected information, and 

 explained the indications, in the light of the geological observa- 

 tions which I had made in the southern part of the State ; and 

 while there, delivered a public lecture upon the subject of Salt 

 and its Geological Belations. 



About the first of March, I drew up a paper embracing a 

 brief exhibit of the geology of the southern peninsula, and a 

 condensed statement of the borings at various localities for salt. 

 This was transmitted to Dr. Potter, the Superintendent of the salt 

 operations at East Saginaw, for the purpose of informing the 

 company which he represented, as to the geological position 

 which their salt boring had reached, and what might be ex- 

 pected as the consequence of continuing to greater depths. For 



