PROCEEDINGS 



OF THE 



AMERICAN PHILOSOPHICAL SOCIETY 



- HELD AT PHILADELPHIA 

 FOR PROMOTING USEFUL KNOWLEDGE 



Vol. XLVIII. May-August, 1909. "/ftRl?-' , ( iV 



CONTENTS. T;'!^^^% 



The Evolution of the City of Rome from its Origin to the Gallic 



Catastrophe. By Jesse Benedict Carter 129 



The Linear Resistance Between Parallel Conducting Cylinders in a 



Medium of Uniform Conductivity. By A. E. Kennelley 142 



On an Adjustment for the Plane Grating Similiar to Rowland's 



Method for the Concave Grating. By Carl Barus 166 



The Electron Method of Standardizing the Coronas of Cloudy Con- 

 densation. By Carl Barus 177 



The Electrometric Measurement of the Voltaic Potential Difference, 

 Between the Two Conductors of a Condenser, Containing a 

 Highly Ionized Medium. By Carl Barus 189 



The Absorption Spectra of Various Potassium, LIranyl, Uranous and 

 Neodymium Salts in Solution and the Effect of Temperature on 

 the Absorption Spectra of Certain Colored Salts in Solution. 

 By Harry C. Jones and W. W. Strong 194 



Earthquakes: Their Causes and Effects. By Edmund Oris Hovey 235 



The Evolution and the Outlook of Seismic Geology. By William 



Herbert Hobbs 259 



Seismological Notes. By Harry Fielding Reid 303 



Some Burial Customs of the Australian Aborigines. By R. H. 



Mathews 313 



PHILADELPHIA 

 THE AMERICAN PHILOSOPHICAL SOCIETY 



104 South Fifth Street 

 1909 



i 



