Camping and woodcraft - Scoutmastercg.com

CAVE EXPLORATION 339face water either disappears quickly after a rain,or collects in ponds, according to whether the ventof the "sink-hole" is open or has been closed. Oftenone comes to a place where the fields are fairlypock-marked with such holes.All this tells a plain story. There are few smallsprings and brooks because the surface rock is soporous or fissured that rain almost immediatelyseeps through it to underground channels. Thesink-holes are simply old cavern chambers withthe roofs fallen in. Generally there are deeperchambers or galleries below them, into which thedrainage flows if the sieve or tube in the funnelVneck has not been closed by accident or design.The great springs are outlets of subterranean rivers.Whenever the underground waters have erodeda channel at a lower level than that which drainedthe original gallery the latter is left dry and formsan extensive cavern that can be opened for exploration.This is provided that the old passages havenot filled up again by a process that will be describedhereafter.Cave Districts.—Some of the caverns alreadyknown in the Ozarks are of noble dimensions. TheMarble Cave, forty miles from Marionville, Mo.,has been traversed for many miles, and to a depthof 400 feet below the surface. One of its vaultedchambers is 350 feet long, 125 feet wide, and 195feet high, by actual measurement. Three milesaway is the exquisitely beautiful Fairy Cave, whichis entered through a sink-hole 100 feet deep. Thereare said to be over a hundred known caves in StoneCounty alone.Crossing the Mississippi into southern Illinois, wefind a cavernous limestone belt in comparativelylevel country. Near Burksville is a cavern that issaid to have been explored fourteen miles one wayand six miles in the opposite direction, withoutfinding- either end. It has a lake, and a riverin which there are blind fish.