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Hills. his is shown four miles west of Orleans at what is called the 
“Wwet-weather rise’ of the dry-bed. Here water flows out as it is flowing 
into the upper sinks, hence water may be flowing through two miles of 
the upper and lower course of the dry bed and not through the middle 
channel. As soon as the flood-water begins to recede at the ‘‘wet-weather 
rise” the direction of the flow changes, and, instead of running out, flows 
back into the opening from which it came. At times the whole under- 
ground system of channels is overtaxed and the water finds an outlet at 
many places, and occasionally through artificial openings, such as the well 
at Brookstown and another east of Orleans. 
The underground channel of Lost River can be reached at three places 
through cavernous openings. At the first of these, near the first sinks, 
the superincumbent limestone is about forty feet thick; at the second 
opening the channel is not less than sixty feet below the Lost River chert; 
at Wesley Chapel Gulf it is thirty feet below the chert stratum, and the 
same at Orangeville. This indicates that the subterranean channel closely 
follows the dip of the strata to the west. 
Comparatively speaking, sinkholes are rarely seen in the Upper Paoli 
limestone, and when they do occur are rough, angular openings in the lime- 
stone, of limited area. They are not an important feature in the surface 
drainage of the country, except in the valleys when located near the level 
of the Lost River chert. 
The tendency of the subterranean channels to unite and diminish in 
‘apacity gives rise to a number of remarkable artesian springs that burst 
forth in great volume near the western limits of the Mitchell limestone 
exposure. The mouth of these springs seems to open into a vertical tunnel 
in the rock, and is always full of water that ordinarily flows gently away 
at one side. The deep blue of their water has given rise to the report that 
they are without bottom. After a heayy rain the volume of water dis- 
charged is very greatly increased and shows the effect of increased pres- 
sure. They are very unlike the wet-cave springs seen on the eastern 
limits of the St. Louis group limestone. The Orangeville and Shirley 
“rises” of Lost River and the Spring Mill head of Lick Creek are examples 
in Orange County. Those near Hardinsburg, Washington County, and 
the Harrison Spring and Blue Spouter, in Harrison County, are others of 
note. 
Wyandotte and Marengo Caves belong to a class of cayerns noted for 
their extent and great beauty. They do not seem to occupy a much higher 
