390 
MR. E. H. GRIFFITHS ON THE VALUE OF 
Date —July 24 to September 18, 1890. 
A = Platinum wire, diameter 'OGo, same as thermometer H (previously annealed). 
B = Copper wire (commercial). 
C = Copper-manganese alloy made by Messrs. Johnson and Matthey —approximate 
composition—‘4 per cent, manganese (previously annealed in carbon).* 
D = Copper and manganese (J and M), 16 per cent, manganese (previously annealed 
in carbon). 
E = Copper and manganese alloy presented to us by Dr. Feusznkr (Mn 10 per cent, 
and Cu 90 per cent.). 
F = Copper-manganese-nickel alloy from Dr. Feuszner (diameter '17 millini.), rather 
more Mn than G and H. 
G = Copper-manganese-nickel alloy from Dr. Feuszner (diameter ’14 millim.), 
Mn 12 per cent., Ni 3 per cent., Cu 85 per cent. 
II = Copper-manganese-nickel alloy from Dr. Feuszner (diameter HO millim.), 
Mn 12 per cent., Ni 3 percent., Cu 85 per cent. 
J = Copper-manganese-nickel alloy supplied by Wolff (diameter '24 millim.), Mn, 
Ni, and Cu, but composition uncertain. 
K = Copper-manganese-nickel alloy supplied by Wolff (diameter '17 millim.) Mn, 
Ni, and Cu, but composition uncertain. 
L = Copper-manganese-nickel aUoy supplied by Wolff (diameter '10 millim.), Mn, 
Ni, and Cu, but composition uncertain. 
M = German silver. 
Table II.—(Temperatures by Air Thermometer.) 
- 20° 
0 
10 
15 
20 
25 
50 
75 
100 
A (Pt) 
•9288 
1 
1-0352 
1-0525 
1-0700 
1-0874 
1-1745 
1-2608 
1-3468 
1 
B (Cu) 
•9382 
1 
1-0306 
1-0468 
1-0627 
1-0790 
1-3054 
C 
•9805 
I 
1-0097 
1-0147 
1-0195 
1-0244 
1-0485 
1-0733 
1-0977 
D 
•9968 
1 
1-0014 
1-0021 
1-0027 
1-0033 
1-0058 
1-0078 
1-0096 
E 
•9976 
1 
1-0009 
1-0013 
1-0017 
1-00-20 
1-0032 
1-0036 
1-0031 
Max. at 75° C. 
F 
•9983 
1 
1-0008 
1-0012 
1-0015 
1-0019 
1-0032 
1-0042 
1-0052 
G 
•9966 
1 
1-0014 
1-0022 
1-0030 
1-0037 
1-0084 
1-0104 
1-0134 
H 
•9999 
1 
1-0000 
•9999 
•9999 
•9998 
•9991 
•9979 
•9967 
Max. at — 5° C. 
J 
.9987 
1 
1-0005 
1-0007 
1-0009 
1-0011 
1-0015 
1-0014 
1-0004 
55° C. 
K 
•9989 
1 
1-0006 
1-0009 
1-0011 
1-0014 
1-0023 
1-0026 
1-0027 
„ 90° C. 
L 
•9986 
1 
1-0005 
1-0007 
1-0008 
1-0010 
1-0014 
1-0014 
1-0011 
„ 65“ C. 
M 
(calculated) 
•9920 
1 
1-0040 
1-0060 
1-0080 
1-0100 
1-0200 
1-0300 
1-0400 
The above resistances were taken with an E.M. F. of four Leclanche cells, and the 
arms of the bridge were 1000/10. A double set of electrodes was used, and the 
* Wc have to thank Mr. C. T. Heycock for his kindness in making an analysis of this alloy. 
