432 GEOLOGY OF OHIO. 



ridge, and in respect of length and of alluvial bottom, is even more im- 

 portant than the stream to which it is nominally tributary. East Fork 

 rises near Martinsville, and has cut for itself a channel in some places, 

 as within three or four miles of Clarksville, nearly one hundred feet deep 

 in the Blue Limestone. 



The East Fork of the Miami drains that part of the county south of the 

 Cincinnati and Marietta railroad, including the neighborhood of New 

 Vienna, and the region south of " Snow Hill " ridge. 



All these streams have in years past furnished motive power for grist 

 and saw-mills, which have, in most instances, been suffered to go to decay 

 upon their banks, on account of the failure of a supply of water sufficient 

 to turn their wheels during enough months of the year to make it profit- 

 able to keep up the mills. This is due, in considerable degree, to the 

 failure of the water in the streams during the late summer and early fall 

 months. The water which fell during the winter and spring months, 

 when the country was new and mostly covered with forest, was retained 

 on the soil. The small streams were choked with rubbish, and the water 

 stood on fiats, protected from speedy evaporation by the dense foliage of 

 the trees, and by the heavy coating of fallen leaves which covered the 

 earth. No artificial drains were in existence. The water gradually 

 trickled from these natural reservoirs, highly colored with the soluble 

 elements of the partially decayed vegetable substances, and kept the 

 streams with at least a partial supply of water during the most of the dry 

 season. Then the mills and dams were less expensive than now, partic- 

 ularly the dams, which were no more than cheap structures of logs and 

 brush, intended chiefly to be of use in changing the current upon the 

 wheel of the mill, rather than in detaining the water in a reservoir. 

 Then the machinery of mills was simple and inexpensive, and was suf- 

 fered to lie idle without detriment during the season when water was 

 insufficient to turn it. Now numerous improvements have been made 

 in mill machinery, without which such quality of flour as is now in de- 

 mand cannot be made, and these, being patented, are more expensive 

 than the machinery which they displaced. More expensive dams are 

 necessary to retain a large quantity of water. Formerly the miller was 

 also generally a farmer, and could make profitable use of the dry season in 

 tilling his farm. For such reasons as these, although the same quantity 

 of water still flows through the same channels, the mills are in decay, 

 and the mill seats abandoned. 



DBAINAGE OF FAYETTE COUNTY. 



A glance at the map of this county shows numerous water-courses 

 traversing the county from its northern to its southern border, varying 



