1042 



The agreement with Ives') is thus pretty close. A large source of 

 uncertainty is due to the sensitiveness of the eye. By selecting 

 observers with normal eyes in the manner proposed by Ives and 

 Kingsbury ') it will undoubtedly be possible to obtain results which 

 are in better mutual agreement. 



Eindhoven. Physical Lab. of Philips' s 



Incandescent lamp- factory . 



M With C2 = 14350 we find M = 0,00143 W/hl. (Note added in translation). 

 2) Ives and Kingsbuey. Trans, ill. Eng. Soc. (X). 317, 1915. 

 Compare particularly Richtmeyer and Crittenden. 111. Eng. Soc. New-York. 

 Febr. 10 and 11, 1916. 



