TRANSACTIONS 



OF THE 



American Philosophical Society 



HELD AT PHILADELPHIA 



For Promoting Useful Knowledge 



Vol. XXI, New Series, Part II. Just Published 



On the Construction of Isobaric Charts for High Levels in tht 



Earth's Atmosphere and their Dynamic Significance. 



By J. YV. Sandstrom, of Stockholm. 



Subscription— Five Dollars per Volume 

 Separate parts are not sold 



Address The Librarian of the 



AMERICAN PHILOSOPHICAL SOCIETY 

 No. 104 South Fifth Street 



PHILADELPHIA, U S. A. 



