350 



tlie apparatus and the formula for the complete radiation of platinum '). 

 The corrections as used were as follows: /t*ioo = J. 70. 10-^, 

 /^ = 0.48.10-6, /f^,8^0.13.10-« and /^l8.^ = 0.005.10-6, Hbem^ 

 the radiation per degi-ee. 



The measurements ai-e collected iir the following taV)les. 



In these tables column I gives the pressure />,„, in cms H(]i ; 

 reduced to 0° C. and 45° latitude; column II Lt, the temperature- 

 difference between the central poition of the long wire and the bath ; 



Q 



(l—k). ht' 

 of heat given off by the two wires expressed in gr. cal. /sec. ; column 



column 



D 



, where (} is the difference of the quantities 



Atm. air at 0^ C. 



^t 



D 



\D' 



A/=n.5o 



D' 



28.355 



13.069 



3.010 



n.428 0.0004358 0.0004353 | 0.0004367 

 n.495 I 4342 4337 4367 



17.860 



4258 



4251 



4378 



1) In the paper quoted above (Ann. d. Phys. (4) 54, 1917, p. 330), where the 

 complete radiation was investigated for platinum and tungsten, it was pointed out, 

 tliat the correction for radiation cannot be determined by a separate experiment 

 in vacuo. This is due to the fact that the distribution of temperature along the 

 heated wire is quite difTerent in vacuo than in a gas. 



