OBSERVATIONS ON INDIANA CAVES. 



A visit of the writer to several caves in Indiana during the 

 months of August and September, 1900, afforded an opportunity for 

 a number of observations which seem to be new or confirmatory of 

 observations previously published by others. The caves visited 

 were Wyandotte Cave, Crawford County; Marengo Cave, Crawford 

 County; Shiloh Cave, Lawrence County; and Coan's Cave, Monroe 

 County, all in the State of Indiana. Detailed descriptions of all 

 these caves have been given in several reports of the Geological Sur- 

 vey of Indiana, the latest and most complete being in the twenty-first 

 annual report, 189b, by W. S. Blatchley. There is also given in that 

 report a bibliography of the caves and their fauna. 



WYANDOTTE CAVE. 



Circular or Dome-shaped Halls. — The hall known as " Helen's 

 Dome" has to a marked degree the form of a hollow cylinder standing 

 vertically. " Rothrock's Cathedral " has the form of a huge dome 

 roofing a short cylinder, the center of the dome being in turn cut by 

 a cylinder rising above it. The "Senate Chamber" has a similar 

 form except that its shape is elliptical rather than circular. "Odd 

 Fellows' Hall," " Milroy's Temple," the "Hall of Representatives," 

 and others are likewise dome-shaped. The hall known as " The 

 Rotunda" in Mammoth Cave has also the form of a dome roofing a 

 short cylinder. The dimensions of some of the halls as given by 

 Blatchley* are as follows: Helen's Dome, 80 feet high and 20 feet 

 in diameter; Rothrock's Cathedral, 185 feet high and 200 feet in 

 diameter; the Senate Chamber, bo feet high with elliptical axes 144 feet 

 and 5b feet in length. The circular or elliptical contour of the walls 

 of these halls and the persistence with which it is maintained through- 

 out successive downfalls of rock is remarkable and indicates that 

 some cause additional to ordinary water erosion must be sought. 



*Op. cit. 



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