Photo-Engraving, Photo-Etching, and Photo-Lithography in Line and Half-Tone

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Besides revising the English edition and incorporating in proper place such additions as I have found useful in practice, I have boiled down the best points from current publications in France and Germany, and added them.