140 GEOLOGY OF OHIO. 
of the numbers 5 and 6 for the coal seams already pointed out. When 
the lines from which dip was to be calculated were run from the Middle 
Kittanning coal in the Tuscarawas or Connotton valleys to the Upper 
Freeport coal, as found at the southward, the two seams being counted 
identical, the 120 to8150 feet between them would of course do some- 
thing toward overcoming the true inclination of the series. Some of 
Whittlesey’s published triangles of dip are vitiated by his acceptance of 
the identity that was claimed for the two coals known as No. 6. 
Stevenson has pointed out several folds in Guernsey and Muskin- 
gum counties, but their pitch is light, and the series very soon resumes 
its normal inclination after they are passed. 
There is hardly a mine in Ohio from which the water inclines to 
run in any other direction than to the south and east. Sometimes a few 
acres will be found to lie nearly level, and many little rolls of the bot- 
tom will throw the water to the west or north for a time, but the main 
drains of all the large mines discharge to the southeast, wherever 
gravity is relied upon to accomplish the drainage. Only one or two ex- 
ceptions to this rule are known in the case of the large mines. The factis . 
of great significance in its bearings upon the dip of the strata. 
As to the amount of the dip, it may be said that it is much more 
variable than the direction. Still the limits are not hard to fix. 
There are some points, and especially in Eastern Ohio, where the 
dip rises to 1°, which gives an inclination of 1 in 57 feet, or in other 
words, about 93 feet to the mile, but the usual limits are between 20 
and 40 feet to the mile. Throughout a considerable part of the Hocking 
Valley, for example, the dip is quite steady at an average of 27 feet to 
the mile, its direction here being about 65° east of south. 
Partines, Roor, FLooR AND JOINTS OF OHIO CoAL SEAMS. 
There are some seams of coal in the Ohio scale that are found with- 
out partings or constant divisions of any sort. The Sharon coal through- 
out the State belongs, as a rule, to this class, and the Lower Kittanning 
coal in Muskingum and Perry counties furnishes another example. 
But by far the larger part of our coals have regular and often very 
persistent divisions in the shape of bands of shale, or fire-clay, or 
pyrites, or mineral charcoal. When the latter occurs in consider- 
able thickness, it is generally charged quite heavily with pyrites, 
and goes by the name of “black sulphur.” ‘These partings are 
