Phil. Mag. Ser. 6, Vol. 24, PI T. 



It 









1 



| 





















H 



- 





- 





\ 



J J 



r 



\ 







i< 



\ 





- 





\ 





/ 





\ 









\ 





■// 





\ 







\ 

 \ 





/ 









11 





\ 





H 





• \ 





„ t 



/■ \ 



\ 





;l 



7^ 





''~ 



i 





\ 







A 











\ 





1 





\ 



!/. 









li 





\\ 





1 





\ 





l 









Jl 



- 



\ 





11 











n 



\ 



' 





/" 



. 









\ 







P 





1 





\ 









\ 





i 





\ 





I 





\ 





1 



• 7 lj 







: 





\ 





1 



e.91.1 



\ 





1 





\ 



~t^C- 











\ 













,,, 









|| 











:r. 



„„„,,. 



■- « 



r::'; 

















/-> 



V\ 











r 



\N 





/I 



'i\ 





/* 



'%— 





/^ 





1! 





\ 







\ 



/ 





\ 



1 





\ 



If 





\ 



( 





\ 



1 





\ 







\ 







\ 



J 





\ 



1/ 





\ 



i 





X 



















F„cH 



r n„ 



■"' 











s. 



„ 



. 



w 

























, j 





h^ 













\ 



i 



^ 









x 





A 







t — i 



\\ 



f 





\ - 



I 





\ 



i 







/ 





X 



1 







r 







■ 





\ 



i 





' 



i 





\ 



/ 





\ 



:i 













i 1 





V 

















e f J/,fj o/ 



T' 



' 













Pi.atk III— lMnlivv I'.i-iU f Fli.-Ur nn.l F..|ii:ility of Brightness Curves. 



Plate IV.— Effect -1 I-'Icuil-iiic. i !.■■ IllniimiMimi with Five Observers. 















































\~ 









\ 







' 



\ 









\ 





















: 

































; 











: ^ 







' 







\ 





/ 







f- 1 



R 



\ 















\ 













/ 





\ 









\ 





1 





\ 





H 









,7 





'\ 









> 







■ % 



\" 





,atr '/ 



: 



\ 







- ■ 











\ 





f 





\ 









\ 





/ 











«™ 







i 









i 



S.B3 



' 







■, SJ 











. 









\ 

















fi.L. 



1*1 ATI, III ft — li.'!;, I iv I'- Ill.ill .,1 l-'Hrli-T Mini J'lljHtllil; ni' 1 Iri.-lj t HO" Cui'VtS. 

















— 



----- 



Cy o/~ 3^h fn mj rfe-l 4oJ 

















«J^ 







A 







,-T 







A* 







^Q 



- 





/^ 









/ 







/ 





\ 



p 







i 





\ 



/ 





\\ 



Z 





\ 







/ 







/ 





S 



1/ 







f 





\ 



7 





\ 



/ 





\ 















































'' i ' 





" 



" 

















5 | 

















^\ r 



\ 





■n 



\ 





<7~ 





/ 





\ 





r 



\\ 







N- 











\ 



// 





\ 



/ 







/ 





\ 



'"/ 



T 



\ ! 

















— V 



II 





\ 









f 





\ 



,/ 





\ 







\ 



4- 













n.u 



__]____ 



M 







m 







=" 







*" 















J 



LATE ^ 



. — Relative Positions o 



f the Two Kinds of Curves for the Five 



Observers. 











