ON STANDARDS OF ELECTRICAL RESISTANCE. 



437 



Becker. The experiments were made in the laboratory of Mr. Gassiot, who 

 kindly gave the iise of his great battery for the purpose. Mr. Willoughby 

 Smith lent his resistance-coils, of 1,102,000 Ohms, Messrs. Forde and Fleem- 

 ing Jenkin lent a galvanometer, a resistance-box, a bridge and a key, and 

 Mr. C. Hockin undertook the observation of the galvanometer, and tlic test- 

 ing of the galvanometer, the resistances, and the micrometer-screw. 



The difference of potentials of the disks was compared with the current 

 in the coils as follows : — One electrode of the great battery was connected to the 

 fixed disk, and the other to the case of the instrument and the guard-ring 



x—x'. Current 



V. Jliit'ccroue oi Uicu ui»jv. 



X. Current through R. 



x'. Current through Gj. 

 through S. 



y. Current through the three coils and G^. 

 M. Mercury cup. T. Torsion head and 



tangent screw. 



A. isuspenUea disk and eoil. 



A'. Counterpoise disk and coil. 



C. Fixed disk and coil. 



Bj. Great battery. B^. Small battery. 



Gj. Primary coil of galvanometer. 



Gj. Secondary coil. 



R. Great resistance. S. Shunt. 



K. Double key. ff. Graduated glass scale. 



One quarter of the micrometer box, disks, and coils is cut away to show the interior. The 

 ca.se of the instrument is not shown. The galvanometer and shunts were 10 feet from the 

 electric balance. 



and the suspended disk. They were also connected through the great re- 

 sistance E, and the primary coil of the galvanometer G shunted with a re- 

 sistance S. 



