276 ]\IE. a. B. AIET ON THE DIEEEEENCE IN THE MAONETIC PEOPEETIES 
The sign of the magnetism in this experiment is opposite to that which would have 
been given by terrestrial induction upon the bars in the position in which they had been 
standing for many days. It appears therefore that the magnetism had been produced 
by some circumstance in the manufacture, and that the terrestrial action upon the bars 
in a quiescent state had not reversed or destroyed it. 
The bars were deposited on the flagstones of the equatorial plane, lettered end 
upwards. 
Experiment 2, February 7, 0^. 
The bars, without being struck or subjected to any other violence, were tried. 
Hot-rolled 
longitudinal. 
Hot-rolled 
transversal. 
Cold-rolled 
longitudinal. 
Cold-rolled 
transversal. 
No. 
Diff. 
readings. 
No. 
Difif. 
readings. 
No. 
Diff. 
readings. 
No. 
Diff. 
readings. 
1 
-f-18 6 
7 
+ 30 
13 
O * 
— 2 10 
19 
+ 25 0 
2 
-fl3 45 
8 
+ 6 45 
14 
+ 6 30 
20 
+ 13 20 
3 
+ 12 20 
9 
+ 60 
15 
+ 5 25 
21 
+ 18 10 
4 
-f 5 0 
10 
+ 4 10 
16 
+ 0 20 
22 
+ 11 50 
5 
+ 11 35 
11 
+ 4 25 
17 
+ 19 40 
23 
+ 5 30 
6 
+ 10 30 
12 
+ 3 10 
18 
+ 7 15 
24 
+ 17 40 
Sum... 
+ 71 10 
Sum... 
+ 27 30 
Sum... 
+ 37 0 
Sum... 
+ 91 30 
Total sum . . . +227° 10'. 
The magnetism, it appears, had very slightly diminished. The bars were retmued to 
the equatorial plane. 
Experiment 3, February 7, I**. 
Each bar as it lay on the flagstones of the equatorial plane, lettered end upwards, was 
struck with three rather heavy blows, from the unlettered to the lettered end. The 
hammer used was a geological hammer, weighing (with handle) about 2|-lbs., and it fell 
in the blows about 2 feet. The bars were immediately examined. 
Hot-rolled 
Hot-rolled 
Cold-rolled 
Cold-roUed 
longitudinal. 
transversal. 
longitudinal. 
transversal. 
No. 
Diff. 
No. 
Diff. 
No. 
Diff. 
No. 
Diff. 
readings. 
readings. 
readings. 
readings. 
1 
o / 
—2 10 
7 
o t 
— 2 20 
13 
O / 
-4 35 
19 
+ 2 40 
2 
+ 0 55 
8 
— 2 40 
14 
+ 0 40 
20 
— 1 30 
3 
+ 0 50 
9 
— 2 0 
15 
-7 45 
21 
+ 3 50 
4 
— 4 40 
10 
— 1 20 
16 
— 2 15 
22 
+ 0 50 
5 
— 1 20 
11 
- 7 20 
17 
+ 0 10 
23 
— 3 50 
6 
— 2 10 
12 
- 6 0 
18 
+ 6 25 
24 
+ 7 0 
Sum... 
— 8 35 
Sum... 
—21 40 
Sum... 
-7 20 
Sum... 
+ 9 0 
Total sum . . . — 28° 35'. 
Upon the whole, the antecedent magnetism is destroyed, and a small amount of mag- 
