116 
DR, W. G. DUFFIELD, MESSRS. THOS. H. BURNHAM AND A. H. DAVIS ON 
Fig. 8. Direct current, Series B. 
Showing the total pressures measured when the fixed carbon was placed East and West of the suspended 
carbon. The mean curves give the values of the pressure when the effect of the earth’s magnetic 
field has been eliminated. 
Table IV. (Burnham). —Direct Current. Variation of Total Pressure with Current. 
Arc-Length Constant (3’5 mm.). After Correction for the Earth’s Field and 
Electromagnetic Effects. 
Current 
in 
amperes. 
Total 
pressure 
on anode 
in dynes. 
Total 
pressure 
on cathode 
in dynes. 
1-5 
-0-32 (2) 
-0-22 
r-6 
-0-19 
1-8 
-0-30 (2) 
-0-17 
2-2 
-0-12 
2-4 
-0-19 
— 
2-6 
— 
-0-05 
2-7 
-0-17 
— 
2-9 
-0-15 
-0-02 
3-0 
— 
-0-01 
3-2 
0 
— 
3-5 
0-03 
— 
3-9 
— 
0-20 (2) 
4-0 
0-09 
Current 
in 
amperes. 
Total 
pressure 
on anode 
in dynes. 
Total 
pressure 
on cathode 
in dynes. 
4-2 
0-13 
4-4 
0-17 
— 
4-7 
0-15 
— 
4-8 
— 
0-34 (2) 
5-0 
0-29 
— 
5-4 
— 
0-48 
6-6 
0-42 (2) 
— 
5-7 
--- 
0-53 
5-8 
0-45 (2) 
— 
6-2 
0-56 (2) 
— 
6-3 
— 
0-63 
6-4 
0-58 (2) 
0-66 
6-7 
0-66 
— 
Current 
in 
ampbres. 
Total 
pressure 
on anode 
in dynes. 
Total 
pressure 
on cathode 
in dynes. 
7-0 
0-74 (2) 
7-6 
0-86 (2) 
— 
7-7 
— 
0-95 
8-0 
0-91 
1-05 
8-2 
— 
1-12 (2) 
8-4 
— 
1-10 (2) 
8-6 
1-01 (2) 
1-19 
8-8 
1-05 
1-17 
9-0 
1-08 
1-31 
9-6 
1-19 
— 
10-0 
1-26 
1-56 (2) 
The figures in brackets indicate the number of observations where more than one were made. 
