SMITHSONIAN INSTITUTION. 



UNITED STATES NATIONAL MUSEUM. 



DIRECTIONS FOR COLLECTING ROCKS AND FOR 

 THE PREPARATION OF THIN SECTIONS. 



GEORGE P. MERRILL, 



Curator o/ the DeJ>arttnent of Geology. 



Part I of Bulletin of the United States National Museum, No. 39. 



WASHINGTON : 



GOVERNMENT PRINTING OFFICE. 

 1895. 



