ELECTRODYNAMIC QUALITIES OF METALS. 69 
Similarly, readings of the deflection were taken as the torsion was taken out, and 
then continued in the opposite direction as far as —200° and back to the original 
starting point. At the end of each of the first seven series the weight was taken off 
and put on again. 
The results are represented in the accompanying diagrams of curves Nos. X. to 
XXIX. In each diagram the numbers at the side indicate the readings on the 
magnetometer scale, and those at the bottom the readings on the torsion circle, a 
cross (X) marks the positions where the couple of torsion was zero, b the beginning, 
and e the end of each experiment. 
224. Explanatory remarks. 
Diagram X. 
Time, July 23, 4 1 ' 12 m to 5 h 25 111 . 
Zero of magnetometer, 90 divisions. 
Stretching weight, 13 lbs. 
Weight off and put on, final reading rose from 790 to 895. 
Diagram XL 
July 24, ll h 0 m to ll h 55 m . 
Stretching weight, 13 lbs. left on from last. 
Zero of magnetometer at end, 85. 
Weight off and on, final reading rose from 815 to 896. 
Diagram XII. 
Time, July 24, 12 h 20 m to l h 5 m . 
Stretching weight, 12 lbs. 
Zero of magnetometer, beginning 85, end 85. 
Weight off and on, final reading rose from 820 to 874. 
Diagram XIII. 
Time, July 24, l h 15 ra to 2 h 0 m . 
Stretching weight, 12 lbs. 
Zero of magnetometer, beginning 85, end 90. 
Weight off and on, final reading rose from 813 to 876. 
Diagram XIV. 
July 26, 12 h 50 m to l h 35 m . 
Stretching weight, 11 lbs. on for 46 hours. 
Zero of magnetometer, at end 95. 
Weight off and on, final reading rose from 800 to 850. 
Diagram XV. 
July 26, l h 45 m to 2 h 25 111 . 
Stretching weight, 11 lbs. 
Zero of magnetometer, at beginning 95, end 100. 
Weight off and on, final reading rose from 803 to 835. 
