CONTENTS 



Original Papers 



Page 



Economics. — The function of research in the regulation of natural monopolies. 

 E. B. Rosa 201 



Mineralogy. — The determination of the order of agreement between obser- 

 vation and theory in mineral analyses. Fred. E. Wright and C. E. Van 

 Orstrand 223 



Physics. A new thermal microscope for the measurement of the optical con- 

 stants of minerals at high temperatures. Fred. E. Wright 232 



Proceedings 

 The Geological Society of Washington 237 



Announcement of Meetings 

 The Semi-Centenary anniversary of the National Academy of Sciences 240 



