222 MM. Elster and Geitel on the Electro-optical 



this source of error by a new adjustment of the ray and cell 

 would have so prolonged the duration of a series of measure- 

 ments, that the change in the zircon-light in the time would, 

 undoubtedly, have proved a source of more serious error. 



The following Tables contain under I. A— D the values of 

 current-intensity observed with the above-described cell for 

 the angles of incidence 70°, 66°, 40°, 23° for each 15° of 

 azimuth. Table II. gives a series for a cell in which the 

 kathode surface was distant about the half radius from the 

 centre of the glass bulb. III. refers to a receiver with 

 windows of plate-glass. 



I. 



Cell L, half-filled with KNa alloy. 



Azimuth a 



0. 



15. 



30. 



45. 



60. 



75. 



90. 





A. Angle of incidence = 70°. 

 27 January, 1895. 



Current-intensity (observed) . 

 Current-intensity (calculated). 

 Difference 



149-6 

 147-3 



+2-6 



138-0 

 137-6 

 +04 



111-0 

 111-3 

 -0-3 



74-6 

 75-2 

 -0-6 



38-9 



39-3 



-0-4 



12-7 



12-9 



-02 



3-2 

 3-2 





B. Angle of incidence = 66°. 



Current-intensity (observed) . 

 Current-intensity (calculated) 



1440 

 1416 

 +2-4 



132-5 



132-4 

 +01 



107-0 

 107-2 

 -0-2 



72-3 



72-8 

 -0-5 



38-3 



38-4 



-01 



125 



13-2 



-0-7 



4-0 

 4-0 





C. Angle of incidence = 40°. 



Current-intensity (observed) . 

 Current-intensity (calculated) 

 Difference 



161-3 

 161-7 

 -0-4 



149-5 

 151-3 

 -1-8 



122-0 

 123-1 

 -1-1 



85-9 



84-5 



+ 1-4 



470 



45-8 

 + 1-2 



190 



17-5 



+ 1-5 



7-1 

 71 







D. Angle of incidence = 23°. 

 1 February, 1895. 



Current-intensity (observed) . 

 Current-intensity (calculated) 

 Difference 



96-8 



97-2 



-0-4 



91-8 



925 



-0-7 



79-7 



79-9 



-0-2 



633 



62-6 



+07 



42-9 

 45-4 

 -2-5 



30-0 



32-7 

 -2-7 



28-1 

 28-1 





