Abr. iia ini) 
THE RISE AND PROGRESS OF PHOTOGRAPHY. 159 
a fatty matter will t to and ta 
i but where the stone is clean and no part of the image is, 
it absorbs water completely and repels the ink, whe 
processes possess a “ discriminative r of absorption,” and 
owe 
that not onl to quantity but at - ners of the ink taken 
ytoq of ee y " 
r 
is rendered ee cable where it is in eae with the 
glass. Another manner is to use chrome alum in the prepara- 
tion. Again, a fine grain is given to its surface in a in “3 
ways, which facilitates the after process of printing. Taken 
they may be considered as taking rank amungst the sane y of 
photo-mechanical processes 
A glass i is ‘camel with a special collodion and dried ; a 
_ Compound of gelatine, sugar, glycerine, and Indian ink is then 
ured on and likewise dried ; this is exposed behind the nega- 
tive. Todt ye: sufficient] “my nesaed it is transferred to another 
eee y made for are arran, eninine 
le, one man eee hla to take charge of si x presses. The 
mould j is now placed on the bed of the press, a warm solution of 
» press 
18 gone through until the six presses have been charged; when 
the pes cea ig is set, the pape are re-opened, ; and t the Paper lifted 
UY es’ 
of the mould which forms the image ; 
= washed and re-dried, when does are veady f for trimming 
