TO HIS EXCELLENCY 

 THE HON. JOHN M. PALMER, 



GOVERNOR OF THE STATE OP ILLINOIS. 



GEOLOGICAL ROOMS, 



SPRINGFIELD, September, 1870. 



SIR : I have the honor of submitting, for publication, the Fourth Volume of 

 my Report on the Geological Survey of Illinois, in accordance with the provi- 

 sions of the first section of an act passed by the Twenty-sixth General Assem- 

 bly, and approved March llth, 1869, entitled, "An act providing for the pub- 

 lication of the fourth volume of the report of the State Geologist, and fixing his 

 salary for the next two years," which section reads as follows : 



Be it enacted by the People of tJie State of Il/inois, represented in t/ie General Assembly, That 

 the publication of three thousand copies of the fourth volume of the report of the state geolo- 

 gist is hereby authorized, and the aum of seven thousand five hundred dollars is hereby appro- 

 priated to defray the cost of the necessary plates, maps, diagrams and drawings ; and also the 

 further sum of fifteen hundred dollars, to complete the necessary drawings for the fifth volume 

 of said report ; said sums of money to be expended under the direction and by the approval of 

 the governor and the state geologist." 



Circumstances entirely beyond my control have prevented the appearance of 

 this volume at an earlier day, and with the present facilities for publication, it 

 is quite impossible to make any reliable calculation upon the time that will be 

 required to place such a volume in the hands of the people, after the material 

 for it has been duly prepared. 



The manuscript for the fifth volume is now ready for the printer, and the 

 plates for the engraver, and the materials for the sixth volume are in hand, and 

 will be prepared for publication as rapidly as possible. These two volumes will 

 include the reports on all the remaining counties in the State, and will com- 

 plete the work of the Survey, in accordance with the plan hitherto pursued. 



I have the honor to be 



Your obedient servant, 



A. H. WOKTHEN. 



