METEORIC AND ARTIFICIAL NICKEL-IRON ALLOYS. 
27 
Ni = 5-81 
C = 0-18 
Si = 0-31 
S = ... 
P = ... 
Mn = 0-65 
Fe (by difference) = 93'05. 
The ring was forged from the rod supplied and turned down until its dimensions 
were nearly the same as those of the meteoric ring. 
The dimensions of the rings, before winding for the permeability measurements, 
were as follows :—- 
Ring. 
External diameter. 
Internal diameter. 
Axial depth. 
centims. 
centims. 
centims. 
Meteoric iron. . . 
5-40 
4-37 
1-89 
Nickel steel . . . 
5-41 
4-37 
1-90 
Section II.—Preliminary Measurements of Permeability at the Air 
Temperature. 
§ 1. The determination of the permeability of the meteoric iron in its original state 
as received was made in the ordinary way by the ballistic method. The ring, of the 
dimensions given above, was wound with a primary and secondary of copper wire, 
each silk-covered and further insulated by a coating of shellac varnish. The inductive 
effects obtained from the ring were compared with those obtained from a standard 
inductor. 
§2. The following numbers represent values obtained at a temperature of 19° C. 
for corresponding values of p and H and of B and H when the values of the latter 
were taken through a cycle. 
H. 
B. 
ix. 
H. 
B. 
/X. 
In C.G.S. units. 
In C.G.S. units. 
0-089 
9-16 
103-2 
-0-261 
-30-03 
0-175 
19-26 
110-3 
-0-346 
-42-57 
— 
0-261 
29-63 
113-7 
-0-261 
-35-15 
— 
0-346 
41-08 
118-8 
-0-176 
-26-95 
— 
0-261 
33-40 
— 
-0-089 
- 17-51 
— 
0-176 
25-19 
— 
o-o 
- 7-68 
— 
0-089 
15-63 
— 
0-089 
3-91 
— 
o-o 
5-25 
— 
0-176 
15-22 
— 
-0-089 
- 6-06 
— 
0-261 
28-02 
— 
-0-176 
- 17-51 
— 
0-344 
40-54 
— 
