nese Manga-
Dia- Dia- Dia- Dia- Copper nese
meter meter meter meter Copper
1.0mm 0.1mm 0.6mm 1.0mm

Copper 60.16 61.63 54.57 53.28 74.41 74.71 70 73

Zinc 25.37 19.67 20.44 16.89 0.23 0.52 ... ...

Tin ... ... ... ... trace ... ...

Nickel 14.03 18.46 24.48 25.31 25.10 24.14 ... 3

Iron 0.30 0.24 0.64 4.46 0.42 0.70 ... ...

Cobalt trace 0.19 ... ... trace trace ... ...

Mang- trace 0.18 0.27 0.37 0.13 0.17 30 24
anese.

99.86 100.37 100.40 100.31 100.24 100.24 ... ...

Specific
resistance
30.0 33.2 44.8 52.5 34.2 32.8 100.6 47.7

Temperature
coefficient
0.00036 0.00030 0.00033 0.00041 0.00019 0.00021 0.00004 0.00003

The specific resistance is in microhms, i.e. 10-6 ohms per cubic
centimetre, and the temperature coefficient in degrees centigrade.

126. Nickel Manganese Copper.

I can find no other reference with regard to this alloy mentioned by
Lindeck. Nicholls, however (Silliman's Journal [3], 39, 171, 1890),
gives some particulars of alloys of copper and ferromanganese. The
following table is taken from Wiedemann's Beiblatter (abstract of
Nicholl's paper, 1890, p. 811). All these alloys appear to require
annealing at a red heat before their resistances are anything like
constant.

Let x be percentage of copper, then 100--x is percentage of
"ferromanganese."

Values of x. 100 99.26 91 .88 86.98 80.4 70.65

Specific
resistance
with respect
to copper
(? pure) 1 1.19 11.28 20.4 27.5 45.1

Temperature
coefficient
per degree
x 10^6(hard) 3202 2167 138 16 22 -24

Ditto (soft) ... ... 184 80 66 21

If nickel is added, alloys of much the same character are obtained,
some with negative temperature coefficients--for instance, one
containing 52.51 per cent copper, 31.27 per cent ferromanganese, and
16.22 nickel.

A detailed account of several alloys will be found in a paper by
Griffiths (Phil. Trans. 1894, p. 390), but as the constants were
determined to a higher order of accuracy than the composition of the
material--or, at all events, to a higher degree of accuracy than
that to which the mater