564 



Intelligence and Miscellaneous Articles. 



ED 2 



obtained we may deduce as rnany values of the expression - 



representing the intensity in Carcels of the light reflected by the 

 mirror above the platinum. In respect of the observers, these 

 values divide into three groups, the respective means of which are 



G 7-018 



N 7-016 



V 7035 



Mean 7-023 



In respect of the lamp they still divide into three groups :- 



i. 



e. 



ie. 



E. 



D. 



D 2 



(A-D) 2 



ED 2 



(A-D) 2 





0-88 



48-2 



42-4 



1-64 



3060 



4-275 



7-011 



7 exp. 



»> 



48-5 



42-7 



1-75 



3033 



4067 



7-066 



3 „ 



j> 



48-4 



42-6 



1-71 



3040 



4-108 

 Mean... 



7023 



8 „ 



7-023 



In the last set the conditions of the lamp were greatly varied ; 

 the following table gives the observations : — 



i. 



e. 



ie. 



E. 



D. 



D 2 



ED 2 





(A-D) 2 



(A-D) 2 



0-86 



47-7 



41 



1-35 



3140 



5-177 



6-989 



3 exp. 



)> 



47-9 



41-2 



1-37 



3130 



5071 



6-947 



2 „ 



>> 



480 



41-3 



1-38 



3130 



5071 



6-998 



2 „ 



0-89 



49-3 



439 



1-70 



3030 



4-135 



7 029 



3 „ 



090 



49-5 



446 



1-80 



2995 



3-857 

 Mean ... 



6943 



2 „ 



6986 



The photometric measurements agree well with the electrical ones. 

 They give for the standard Carcel oTfjQ> a value near that which we 



found directly. 



In conclusion, platinum at its melting-point fulfils the con- 

 ditions which we can require for an absolute standard of light ; it 

 depends on a perfectly definite and constant physical phenomenon, 

 and being of a suitable magnitude it forms a practical term of 

 comparison with the usual standards. — Comptes Rendus, April 28, 

 1884. 



