Prof. Loomis on Electricity of Zinc buried in the earth. 5 
No. of Size of the Copper surface Deviation of |‘Tangent of 
Experiment.,| | Copper Plate. | immersed. Galvanometer.| deviation 
14 48 inches by 14 1354 square inches. 74§° 3°668 
15 2 = 14 682 715 2°989 
4 16 12 7 14 346 ” 684 2507 
7 6 ¥ 14 178 * 664 2-300 
18 6 “ 4 94 . 644 2120 
19 3 . i! 52 “i 624 1-921 . 
20 3 ij 84 31 . 604 1-786 
21 3 i 2 22 2 59 1664 
22 3 = 1 16 ag 57 1540 
23 3 xt 4 13 564 1511 
Length of wire immersed, 4 
24 6 feet. 108 S 56 1-483 
25 54 « 99 “ 554 1442 
26 3 « B4 « 464 1-063 
27 : 18 “ 324 6 
28 6 inches. Q°9 * 19 “B44 
29 Pies 0-45 Ls 11 194 
The law which these numbers follow is exhibited by the fol- 
lowing curve, in which the abscissas represent the amount of 
copper surface immersed in the water, and the ordinates represent 
the intensity of the electric current, maeailite the intensity to be — 
proportioned to the tangent of the angle of deviation of the gal- — 
vanometer. 
wee 
il 
ger: f 
u a lj 
800 1000 1200 1400 
ow the horizontal line represent the square inches of copper surface immersed : 
es represent the corresponding intensity of the clectric current. 
Thus it appears that for plates less than one square inch, the 
tT 8) 
$§ 
