SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE. 



RESEARCHES 



ELECTRICAL RHEOMETRY, 



A. SECCHI, 



PROFESSOR OF ASTRONOMY AND DIRECTOR OF THE OBSERVATORY IN THE ROMAN COLLEGE (rOMe), AND 

 LATE PROFESSOR OF PHYSICS AND ASTRONOMY IN GEORGETOWN COLLEGE (d. c). 



ACCEPTED FOK PUBLICATION 



BY THE SMITHSONIAN INSTITUTION, 



SEPTEMBER, 1850. 



