viii PEEPACB. 



the value of the' results of the Survey until all this matter shall have been submitted 

 to them in printed form ; but the degree of favor -with which the reports already pub- 

 lished have been received, will perhaps be accepted as proof that the work of the 

 Survey has been, and is being satisfactorily done, and that when finished it will not be 

 discreditable to those engaged in it or to the State. It is but just, however, to the mem- 

 bers of the Geological Corps, to state that they do not regard their work ae in any sense 

 exhaustive and complete, but as at least a fair return for the time it has occupied, and 

 the money expended upon it. To make a minute and thorough survey of a great and 

 rich state like ours, would reciuire a very large sum and many years of time, but the 

 present survey was begun with a guaranty of only three years' continuance. Although 

 subsequently extended by act of Legislature, no provision was made for its support 

 in vigor and activity for more than five years; and whatever has been done since the ex- 

 piration of that period has been largely as a gratuity on the part of those who accom- 

 plished it. When the materials collected by the Survey shall all have been worked up, 

 the total expenses of field and office work will amount to about $100,000, a sum which 

 will not appear extravagant when it is known that for the field and office work of the 

 Second Geological Surrey of our neighboring State, Pennsylvania, $350,000 have 

 already been appropriated. ' 



The cost of thepublioatioQ of the rt'ports of the Ohio Survey has been large, because 

 they have been issued in editions of 20,000 copies ; but for that expenditure the Geolo- 

 gical Corps is not responsible, since it was made by independent and unsolicited action 

 of the Legislature. 



In the preface to Vol. II, Geology, an explanation has been given of the differences of 

 the volumes of the report in size and in the quality paper used. For these differences 

 and for the fact that the typographical execution in style and accuracy leaves much to 

 be desired, the Geological Corps is not accountable. The errors in typography are such 

 as are incident to the wholesale and hurried manner in which our public documents are 

 printed. 



The proof reading and also a measure of editorial supervision of the present volume 

 have been turned over to Prof. Edward Orton, but in justice to him it must be stated 

 that it has occasionally been found necessary to print one or more forms during his 

 absence from home. For the errors occurring in such forms he is not responsible. It 

 has not been possible, in any case, to send away proofs of the reports to their several 

 authors for revision. 



J. S. N. 



