RADIATION IN ABSOLUTE MEASURE. 
447 
Asymptotic Experiments, March 22 to March 30, 1887. Slider placed at 500 of scale 
(see fig. 1). Barometric height, 740 mm. Temperature of wire, 408° C. 
Temperature 
of water- 
jacket. 
Pressure. 
Current. 
CTt/J.s-. 
Total emission divided by 
lowest emission observed 
(378-8 x lO -4 ), which is taken 
as unity. 
°C. 
mm. 
Amperes. 
16 
740 
2-1776 
8137 x 
IQ-4 
21-48 
560 
2-1603 
8004 
2113 
440 
2-1560 
7971 
21-04 
340 
2-1538 
7956 
21-00 
240 
2-1517 
7941 
20-96 
140 
2-1431 
7875 
2079 
90 
2-1345 
7818 
20-64 
64 
2-1172 
7686 
20-29 
52 
21129 
7658 
20-21 
49 
2-1108 
7643 
20T8 
42 
2-1042 
7591 
20-04 
34 
2-0999 
7563 
19-96 
17 
24 
2-0784 
7408 
19-56 
17-2 
2-0558 
7249 
19-14 
13 2 
2-0352 
7104 
18-75 
5-7 
1-9880 
6314 
16-67 
4-0 
1-8757 
6036 
15-93 
2-5 
1-7291 
5125 
13-53 
1-7 
1-5954 
4364 
11-52 
0-88 
1 -4264 
3487 
9-206 
•444 
1-2505 
2683 
7-096 
15 
■141 
•9357 
1502 
3-965 
•094 
•8300 
1181 
3-118 
•070 
•7805 
1045 
2-759 
•053 
•7287 
910-5 
2-404 
•034 
•6511 
727-3 
1-920 
•012 
•5606 
639-2 
1-423 
•0071* 
•5174 
459T 
1-212 
•0051* 
•5045 
436 4 
1-152 
15 
•00015* 
•4786 
392-7 
1-037 
16 
•00007* 
•4700 
378-8f 
1-0 
* Pressures observed, but uncertain, owing to lagging of McLeod gauge. 
t Further diminution of pressure by continued working of Sprengel pump made no diminution in the 
amount of radiation, which remained unaltered during more than an hour of working. 
