Gradation of a Developed Photographic Image. 319 



Table XVII.— Densities. 



Aperture of 

 sectors. 



Scale number. 



17 -6 



(A 4450) 



3 3 

 (A 4100) 



-6 -7 



(A 4130) 



— 15 -8 



(X 3940) 



5 



60 



78 



85 



93 



10 



75 



95 



102 



119 



20 



97 



118 



127 



145 



40 



118 



142 



153 



171 



80 



140 



165 



171 



185 



160 



152 



185 



187 



192 



Table XVIII.— Densities. 



Aperture of 

 sectors. 



Scale number. 



32-7 



(A 4952) 



22 -8 

 (A 4602) 



14 -5 



(A 4364) 



o 



5 



35 



77 



45 



10 



41 



101 



57 | 



20 



58 



124 



75 



40 



72 



146 



99 



80 



90 



169 



122 ! 



160 



114 



192 



147 i 



320 



138 



202 



171 ! 



Table XIX. 



Scale 



Gradation 



Scale 



Gradation 



Scale 



Gradation 



number. 



factor. 



| number. 



factor. 



number. 



factor. 



55 -4 



1-35 



25-0 



1-00 



-6*7 



1-19 



40-6 



1-13 



15-0 



1-05 



-15-8 



1-23 



31 -4 



1-05 



6*6 



1-09 



32 -7 



1-05 



22 2 



10 



17-6 



1 -025 



22 -8 



1 -oo 



39 3 



112 



3-3 



1 -10 



14 -5 



1 -04 



It will be seen that these gradation factors are very closely the same 

 as those obtained by the other plan of altering the time exposures, 

 the intensity of the light acting remaining the same. The curve in 

 these results has been pushed further into the ultra-violet than in the 

 other experiments. 



