Century. Problems of the Atmosphere. Low Temperature Investigations. Liquid 

 Hydrogen Calorimetry. New Low Temperature Phenomena. Studies on Charcoal 

 and Liquid Air. Studies in High Vacua and Helium at Low Temperatures. The 

 Nadir of Temperature and Allied Problems. Problems of Helium and Radium. 

 Light Reactions at Low Temperatures. Chemical and Physical Change at Low 

 Temperatures. Heat Problems. The Coming of Age of the " Vacuum Flask," 



JOSEPH JOHN THOMSON, 



Professor Royal Institution from 1905 to the present date. 



Application of Theory of Electric Discharge to Spectroscopy. Rays of Positive 

 Electricity. Carriers of Positive Electricity. Electrical Striations. TJie Dynamics 

 of a Golf Ball. A New Method of Chemical Analysis. Results of the Application 

 oF~1 5> T5sitive Rays to the Study of Chemical Problems. Further Applications of the 

 Method of Positive Rays. Further Researches in Positive Rays. 



