Brown——The Densities and Specific Heats of some Alloys of Iron. 
TasLeE XVII. 
CopPER STEELS. 
Percentage Composition Specific 
Heat 
Mark C Mn Al Cu o pxc 
1264 A 0°68 0°36 1:59 0:1180 0:9246 
1264 B 0°59 0°32 2°50 0:1180 0:9259 
1263 C 0:17 1:04 2°87 0:1178 09244 
1149 A 0°04 0°16 1:00 3°75 0:1178 0:9088 
The results for the four copper steels are here given in Table XVII., and in 
this case also the effects of the copper on the specific heat seem to be masked by 
the carbon present; in fact, the results for the first two specimens practically lie 
on the carbon curve in fig. 5. 
In the third specimen marked 1263 C with a less amount of carbon, but with 
a higher percentage of manganese, the specific heat is practically the same as in 
the first two specimens, showing that the copper present has little or no effect 
on the specific heat. The last specimen in Table XVilI. contains 1 per cent. 
of aluminium; and, judging from the aluminium steels in ‘Table XIX., below, the 
presence of 3°75 per cent. of copper seems to raise the specific heat a little. 
The last column in Table XVII. shows that the thermal capacity per unit 
volume is fairly constant. 
Taste XVIII. 
CoBALT STEELS. 
Percentage Composition Specific 
Heat 
Mark C Mn Si Co o pxo 
1209 C 0:25 1:0 0°64 1:80 0:11538 0°9007 
1209 F 0°52 0°8 0°80 7:00 0°1157 0:9062 
The results of the two cobalt steels in Table XVIII. show that cobalt added to 
iron has very little effect on the specific heat when there are other elements present. 
