

j^ru/r-^. 



PROCEEDINGS OF THE 



AMEKICAN PHILOSOPHICAL SOCIETY. 



HELD AT PHILADELPHIA, FOR PROMOTING USEFUL KNOWLEDGE. 



VOL. IX. JNo. 70. 



CONTENTS. 



June 19, 1863. page 



On Solar Spots. By Dr. 0. Reich enbach 234 



September 18, 18G3. 

 Catalogue of a Collection of Trade Tokens. By P. E. Chase . . 242 



October 2, 1863. 



Biographical Notice of Charles Jared Ingersoll. By G. Sharswood 260 

 Note on possible Vowel Sounds not used in any Language. By P, 



E. Chase 271 



December 4, 1 863. 

 On the Application of Forces to the Screw Bolt. By R. Briggs . 278 



December 18, 1863. 



Letter on Photography. By Prof. Zantedkschi 281 



On the Diurnal Variation of the Barometer. By P. E. Chase . . 283 



Note. — With the next number will be issued to such Corres- 

 pondents as signify their desire for it, the Title page and wanting 

 numbers of Vol. I. of the Proceedings of the American Philoso- 

 q)hical Society, in order to permit the set to be bound. 



