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HALLS 73, 74 AND 75. 
Hall 73. — Office of the Department of Geology. 
Hall 74. — Library of the Department of Geology. The 
works in this library treat of geology and kindred subjects, and are 
intended primarily for the use of officers of the Department. On 
application to the Curator, however, opportunity will be given to 
visitors to consult any special work. The collection of photographs 
and autographs of leading geologists and mineralogists of the 
world, made by Mr. Geo. F. Kunz, is exhibited here. 
Hall 75.— Laboratory of the Department of Geology. Here 
are contained over fifty sketches enlarged from wood-cuts in De 
Re Metallica . showing methods of mining and metal working 
appliances used in the sixteenth century, and twenty-five photo- 
graphs of the works at Playa Blanca, Chile, showing furnaces and 
apparatus used in the treatment of ores of that locality. 
Permission to examine these can be obtained from the Cura- 
tor. 
