Practically a copper nickel alloy, used to some extent by Siemens and Halske. It stands pretty well in the same relation to nickelin as the latter does to German silver. After annealing as for manganin it can be made into serviceable standards which do not change more than a few thousandths per cent. I have not come across a statement of its thermo-voltage against copper. Sec. 125. Constantin. Another nickel copper alloy containing 50 per cent of each constituent. It appears to be a serviceable substance, having a temperature coefficient of 0.003 per cent per degree only, but an exceedingly high thermo-voltage, viz. 40 micro-volts per degree against copper. 1 2 3 4 5 6 7 8 German Nickelin made Rheo- Patent Nickel Manga- Nickel Silver by Obermaier tane 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