THERMAL EMISSIVITY OF THIN WIRES IN AIR. 
387 
Table VII. 
Diameter, 14 mils, or 0*356 millim. Length, 28*09 centims. Water-jacket, 14°*5 C. 
May 3rd, 1888. Fig. 11. (Plate 14.) 
Current, 
iu amperes. 
P.D., 
in volts. 
Resistance, 
in ohms. 
Equivalent 
temperature of 
wire. 
Emissivity. 
° C. 
' 0-05 
0-01584 
0-3168 
0-075 
0-02395 
0-3195 
o-io 
0-03198 
0-3198 
0-15 
0-04853 
0-3235 
0-20 
0-06386 
0-3193 
0-25 
0-07900 
0-3160 
0-30 
0-09464 
0-3155 
0-40 
0-1268 
0-3170 
0-50 
0-1602 
0-3204 
17-4 
•002104 
0-60 
0-1939 
0-3232 
19-7 
•001705 
0-80 
0-2627 
0-3284 
24-6 
•001585 
1-00 
0-3349 
0-3349 
30-0 
■001645 
1-20 
0-4091 
0-3409 
35-7 
•001764 
1-50 
0-5334 
0-3556 
50-4 
■001698 
1-80 
0-6667 
0 3700 
64-5 
•001825 
2-10 
0-8261 
0-3934 
87-0 
•001820 
2-40 
1-004 
0-4182 
111-0 
•001899 
2-70 
1-201 
0-4449 
137-4 
•002005 
3-00 
1-439 
0-4796 
172-5 
•002074 
3-40 
1-815 
0-5338 
226-6 
•002207 
3-80 
2-291 
0-6029 
304-0 
•002278 
The first eight observations in the above Table were made to enable the early part 
of the curve in fig. 9 to be plotted, so as to find the resistance of the wire that 
corresponded with current nought; and this the curve shows to be 0*318 ohm. The 
wire, then, at the temperature of the water-jacket, viz., 14°*5 C., has this resistance, 
0*318 ohm. 
3 u 2 
