CAVES 123 



the Arizona mining exhibit at the Columbian Exposition in 1893. 

 Enlarged photographic transparencies give details of scenery and mining, 

 supplementing what is shown by the models. The work of treating 

 the ores at the smelter in Douglas near Bisbee is demonstrated in a 

 neigliboring case. 



The northwest corner of the hall contains a display of caves and cave 

 material including a reproduction of part of a beautiful 

 cave that was discovered early in 1910 in mining opera- 

 tions at the Copper Queen mine. The cave was formed by the dissolv- 

 ing action of water traversing joints in limestone, and its walls, roof 

 and bottom were afterward coated with calcite (calc spar) incrustations, 

 stalactites and stalagmites, some of which are dazzling white while 

 others are colored green with copper salts or pink with manganese 

 compounds. 



Alongside the Copper Queen cave is a reproduction of a chamber in 

 Weyer's Cave, Mrginia. Weyer's Cave is in a region of much heavier 

 rainfall than Bisbee, which is probably the principal factor in pro- 

 ducing a greater wealth of regular stalactite and stalagmite growth than 

 adorns the Copper Queen cave, and this exhibit illustrates not only 

 their great variety in form but the reasons for this extraordinary 

 diversity. 



Among the cave material shown nearby is a series of tumblers into 

 which water from the stalactites was allowed to drip for stated periods, 

 the thickness of the deposit giving some measure of the length of time 

 necessary for the formation of stalactites and stalagmites. 



Particularly attractive are the marvelously beautiful specimens 



of calcite, aragonite and gypsum from the famous silver- 



ua ua and-lead mines near Santa Eulalia in the vicinity of 

 Cave Material 



Chihuahua, Mexico. These specimens are remarkable 



for the perfection of their crystalline form or the delicacy of their fibrous 



developments and for their colors. 



[Return to the Hall of Mastodons and Mammoths and turning to the 

 right enter the West Corridor or Gem Hall.] 



