Nags 
ge we JA 8 Ei 
Foreword Cp Piet N 
aes ta 5 
The main idea kept in view in the compilation of this 
book has been to provide in condensed form working 
formulas and instructions for the various processes of 
photography. There must necessarily be errors of 
omission and commission, and the publishers will be 
grateful to any reader who, consulting its pages and 
failing to find what he requires, will at once communi- 
cate with them, in order that the omissions may be 
remedied in future editions. Forms for this purpose 
will be found at the end of the book. 
The formulas given have not been selected in hap- 
hazard fashion but, as far as possible, only from credit- 
able sources. 
Certain valuable information, received after the body 
of the book was made up into pages, will be found in 
the Appendix at page 376. 
