No. 55 398. 



Radiant Heat. 



647 



5538755390. 1:4. 



55391 55394. 1:6. 



55 395. 1 : 4. 



55 397. 1 : 5. 



55 398. 1 : 7. 



Thermopiles, Figure, arranged oblong, with mount, and gap opening symmetrically. 



List No. 55,391 55,392 55,393 55,394 

 Number of Elements 24 36 48 60 



2.14.0 3.6.0 4.4.0 5.0.0 



55.395. Linear Thermopile after Eubens, Figure, consisting of 20 elements of iron and 

 constantan, in mount, with German silver reflector polished inside, on adjustable stand 

 (Ztsehr. fur Instrumentenkunde, 18, 1898, p. 64; Ztschr. f. d. phys. u. chem. U., 11, 

 1898, p. 126) 



55.396. Tinfoil Screen, on Base, Fig. 55,010 A, p. 600 (W. D., Fig. 374 [354]), with silver- 

 mercury iodide paint and black ring, for explaining Power of Absorption and Eeflection 



55.397. Steam Capsule after Weinhold, for Radiation Experiments, Figure (W. D., Fig. 369 

 [349]), on stand 



55.398. Apparatus after Eitchie, Figure, for showing the relation between Emissive and 

 Absorptive Power (Gan.-Eein., Fig. 410) > . 



The apparatus, having the form of a differential thermometer, possesses two similar metallic air 

 capsules and one of medium size intended 1<> he tilled with warm water. All capsules are white on 

 one side and black on the other. 



s. d. 



3. 14. 

 0. 8.0 

 0.12.0 

 2. 2.0 



Cl. 1040, 1041, 



1948, 1919. 



1942, 



