COAL MEASURES. 1 49 



upon the lower. As an agricultural district, it is absolutely self- 

 sustaining, if we moderate our claims to the necessities of life. A 

 mining district without agriculture, if yet full of gold, would let 

 its inhabitants starve to death, if the agriculturist did not come 

 to their relief. 



When it became my duty to investigate the Lower Peninsula, I 

 was already informed of the general facts concerning its structure, 

 and I felt somewhat uneasy when I thought that I had no prospect 

 of discovering any great mineral wealth within it, because I knew 

 that there is a general feeling that the geologist should make 

 numerous new discoveries, and report at length about the details of 

 the rock formations, etc. I believe that I have done conscien- 

 tiously all that could be done under given circumstances, but I 

 have had to be more brief in the description of many things than 

 was my wish, for the simple reason that I had not the opportunities 

 to make more extended observations, on account of the very 

 unfavorable and restricted exposures of the rock beds, which, as 

 already explained, are in the greatest part of their extension cover- 

 ed by an unbroken mantle of drift masses. Perhaps I could have 

 entertained the reader a little better by giving hypothetical 

 speculations on things which could not be seen ; but this would 

 have been in opposition to my principle, which is to give facts 

 only, as a guidance for the enterprises of explorers, and for the 

 student of the earth's history. 



The benefit to the commonwealth of a geological investiga- 

 tion consists not only in adding discoveries of new stores of min- 

 erals to those already known, but to a much greater extent, I think, 

 in causing to be fairly understood the uselessness of explorations 

 for certain minerals in places where they do not exist. Thousands 

 and thousands of dollars have been spent in this way, which could 

 have been saved to their owners, if they had had a clear comprehen- 

 sion of the structure of the earth's crust which they explored, or 

 had asked advice of some one better informed than themselves, 

 before they commenced their work ; and in such sense, I know 

 that the contributions to knowledge which I have made in this 

 report will return to the State an ample equivalent for the ex- 

 pense of the investigation. 



As an appendix to the foregoing report, exclusively devoted to 



