336 Scientific Intelligence. 
Kirchhoff. |Wave-length. Kirchhoff. |Wave-length. Kirchhoff. |Wave-length. 
1601°6 52075 2002 491-78 2457-5 456°31 
1622-4 519-10 2018 490-87 2467-4 455°21 
518-16 2041-4 489-00 2489-4 453'28 
b 1648-8 517-13 2058 487-64 2587-1 450-06 
16 51658 2067 487-01 25472 449°64 
1693°8 51408 F 2080-1 485:97 2566°3 44797 
17876 510°8 103°3 48410 2606 44551 
1750-4 509-74 2119°8 482:28 2627 44416 
1777-4 50785 2148-9 480:03 2638°6 443°36 
1799 506°35 2157-4 479-02 2670 441-40 
1834 504°00 2160°6 478:70 2686'6 44039 
1854'5 502-70 218771 47641 ST2i6 438:°27 
18 501-71 2201-9 475°38 2784°9 48732 
1873°5 50112 2221-7 47382 277156 435°19 
1885°8 500°52 2233-7 47284 2797 4383°86 
1908°5 49917 2250 4707 82 433°34 
920 498-28 2264°3 47019 G 28547 430°88 
1961 49561 2309 466°56 8 90 
19756 494-50 2416 460°12 896°68 
19838 493°80 2436°5 458°16 EL" 393°32 
: 1989°5 49322 
—Sitzungsberichte der k, k, Akad. der Wissenschaften, 1, Band 296. 
w. G. 
tity, however, according to Dulong’s formulas, only 102 units of hea 
per minute were lost by radiation alone, the external temperature being 
17° C. This source of heat placed at a distance of 0-8 meters from the 
thermopile produced a constant deviation of 17°-8; hence any source of 
heat or light, which at a distance of 0-8 meter from the thermopile pro- 
uces a deviation of 17°-8 C., radiates 102 units of heat per minute; 
and since the deviations of the needle within certain limits are propor 
were placed. A candle was then placed at a distance of 0°8 meter from 
- the thermo-pile and a constant deviation of 36°5 obtained. Hence the 
total radiation of a candle burning 8-2 grams of spermaceti per hour was 
