ON THE EFFECTIVE TEMPERATURE OF THE SUH. 
375 
It will be noticed at once that at comparatively low temperatures the curve does 
not accurately express the facts, but that the agreement is very good as the tempera¬ 
ture rises. This disagreement has been confirmed by Leconte Stevens, whose paper* 
came under our notice after our experiments were finished and the curve drawn. 
He concludes that, at comparatively low temperatures, the fourth power law gives too 
rapid a rate of increase of radiation, which agrees with our observations, but that as 
the temperature rises this divergence diminishes. 
The following table gives the results of the three series of observations, which are 
also plotted on the curve, fig. 6 ; in two cases, the difference between the observed 
and calculated results is so large that some misreading seems likely, otherwise the 
agreement is very satisfactory 
Table I. 
Temperature 
Radiation. 
absolute. 
Ob.served. 
Calculated. 
Calculated—ob.served. 
o 
288 
0 
0 
0 
G71 
7 
9 
+ 2 
703 
9 
11 
+ 2 
788 
16 
18 
+ 2 
811 
18 
20 
+ 2 
87G 
26 
27 
+ 1 
915 
32 
33 
+ 1 
944 
37 
37 
0 
965 
39 
41 
+ 2 
1045 
59 
57 
— 2 
1125 
76 
76 
0 
1181 
93 
93 
0 
1253 
120 
119 
- ] 
1308 
140 
140 
0 
1348 
161 
158 
- 3 
1363 
172 
159 
(-13) 
1393 
182 
180 
— 2 
1425 
202 
198 
- 4 
1466 
236 
220 
(-16) 
1513 
253 
252 
- 1 
1547 
280 
272 
- 8 
1593 
305 
306 
4- 1 
1647 
348 
348 
0 
1663 
358 
360 
+ 2 
1683 
373 
380 
+ 7 
1773 
460 
462 
+ 2 
Mean. 
+ 24 - 50 26 
26 ~ ~ 26 ~ ^ 
- 
* ‘ Amev. Jour, of Science,’ vol. 44, 1892, p. 431. 
