66 
MESSRS. W. DE LA RUE AND H. W. MULLER ON THE 
Striking distance between two spherical surfaces each 1 # 5 inch in diameter, the 
radius of curvature being 3 inches. 
1080 CELLS. 
1200 CELLS. 
2160 CELLS. 
inch. 
inch. 
inch. 
1876. Feb. 24* 0-00750 
1876. June 9 0"00600 
1876. Feb. 24 
0-0145 
0-00600 
0-00575 
0-0143 
0-00500 
0-00575 
0-0143 
0-00500 
0-00575 
0-0143 
0-00450 
0-00600 
Oct. 20 
0-0142 
0-00450 
June 10 0-00550 
0-0142 
0-00480 
0-00575 
0-0142 
0-00500 
0-00600 
0-0142 
June 9 0-00475 
0-00625 
0-0144 
0-00450 
0-00425 
1877. June 5 0-00650 
0-00600 
0-0148 
June 10 0-00450 
0-00475 
0-00450 
Oct. 20 0-00425 
0-00425 
0-00425 
0-00440 
0-00440 
0-00440 
0-00440 
0-00440 
2400 CELLS. 
3240 CELLS. 
3600 CELLS. 
inch. 
inch. 
inch. 
1876. June 9 0-0170 
1876. Feb. 2 0-02430 
1876. June 9 
0-030 
0-0170 
0-02550 
0-030 
0-0170 
0-02550 
June 10 
0-030 
0-0170 
Oct. 20 0-02525 
0-030 
0-0170 
0-0170 
June 10 0-0175 
0-0180 
0-02525 
0-02525 
0-02524 
0-02524 
1877. June 5 
0-029 
1877. June 5 0'0160 
4320 CELLS. 
4800 CELLS. 
5400 CELLS. 
inch. 
inch. 
inch. 
1876. Feb. 24 0'0360 
1876. June 9 0"04400 
1876. Feb. 24 
0-0490 
0-0375 
0-04400 
Oct. 20 
0-0490 
Oct. 20 0-0370 
June 10 0-04375 
0-0495 
0-0372 
1877. June 5 0‘04300 
0-0500 
0-0375 
0-0375 
4 Here and elsewhere throughout this paper, except where the contrary is expressly stated, it is to 
be understood that the different observations recorded for the same date were obtained with different 
batteries. 
