360 



Mr. S. P. Owen on Radiation 



If N = normal radiation from the element at G, the total 

 radiation received from G at F 



N cos cos </> sin <£ . r . dr dd dx dc 



d? 



where r .drd6 = sive& of the element at F, 



dxdc —area of the element at G ; dc being an ele- 

 ment of the circumference of the cylinder, 

 and d = FG. 



This will be absorbed by the disk if the latter be a perfect 

 absorber of radiation. 



The total radiation received by the whole plate from the 

 whole cylinder 



= 2 f 2na P f 8m " f DB Ncos ^ cos » :siu ^» yi 



Jo J*x Jo Jl)A <1- 



where x x ~ DK and #g = DM, 



r/r d# . dx . dc 



, . (1) 



