GEOLOGICAL SURVEYS OF OHIO. 



But little was known of the geology of Ohio so long as its 

 surface was covered with the primeval forest. Bedded rock, 

 suitable for use as building stone, was found, if at all, by the 

 early settlers in the valleys of the principal streams. In many 

 districts such stone was hauled a dozen miles or more where now 

 as good or better can be found in every mile of the interval. 

 The clearing away of the forest, the drainage of the swamps and 

 the straightening of the channels of the streams have increased the 

 efficiency of the floods to such an extent that scores or hundreds of 

 exposures of rock are now found where a hundred years ago there 

 was but one. The presence of coal in the southeastern quarter of 

 the State was not unknown at an early date ; but it is surprising to 

 find at how few points it was noted by the early occupants of the 

 country, and how completely the most important seams, as we 

 now know them, were concealed 'from view. 



The earliest scientific observations extant on the geology of 

 the State, which I have been able to discover, are to be found in 

 Sillima/t's Journal. In Volume I., 1818, two communications 

 appear from the pen of Caleb Atwater, Esq., of Circleville, one 

 on the Origin of the Prairies and Barrens of the West, including 

 northern Ohio, and the second on the Scenery, Geology, Miner- 

 alogy, etc., of Belmont County. 



Between 1820 and 1835 numerous notes and papers appeared 

 in the same journal on the geology of Ohio, some of which were of 

 extreme interest and value. Three articles in particular, written 

 by Dr. S. P. Hildreth, of Marietta, and published respectively in 

 1826, 1828 and 1832, deserve special mention as by far the best 

 statements that had appeared up to this date on the geological 

 order of the Coal Measures of the State. Many important facts 

 concerning their stratigraphy and structure were clearly recog- 

 nized and stated, and very interesting information was furnished 



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