PROCEEDINGS 



AMERICAN PHILOSOPHICAL SOCIETY 



HELD AT PHILADELPHIA 



PROMOTING USEFUL KNOWLEDGE. 



Vol. XX. 



JAN. 1882 TO APRIL 1883. 



NOS. 110, 111, 112, 113. 



PHILADELPHIA : 

 PRINTED FOR THE SOCIETY 



BY m'CALiLA & STAVELT. 



^883. 



