Vienna.
On receiving this work for review I was greatly struck with the thoroughly practical manner in which it was written, and thought that an English translation might be acceptable to the large and ever increasing class of photo-mechanical workers who might not otherwise have the opportunity of reading it in the original. I have kept to the author’s text as close as is consistent with the idiomatic construction of German.
I am indebted to Messrs. Hazell, Watson and Viney for permission to undertake the task of translating the work for another firm of publishers, and I hope the translation may prove as acceptable and useful to the readers as it has been pleasurable to me to do it.
E. J. WALL.
1, Creed Lane,
London, E.C.
INTRODUCTION.
1.—The theory of printing from stone.
The theoretical principle of lithography is purely chemical, and is based principally on the repulsion of water and other substances by fatty bodies, and the alteration of these greasy bodies by acids. As the support for this chemical opposition a stone or zinc plate is used, which are sufficiently porous to allow grease, water, acid, and certain resinous solutions to penetrate to a certain degree.