Gas-Engines and Producer-Gas Plants&#13;A Practice Treatise Setting Forth the Principles of Gas-Engines and Producer Design, the Selection and Installation of an Engine, Conditions of Perfect Operation, Producer-Gas Engines and Their Possibilities, the Care of Gas-Engines and Producer-Gas Plants, with a Chapter on Volatile Hydrocarbon and Oil Engines by Mathot, Rodolphe Edgard Kaempffert, Waldemar
 is a Project Gutenberg book, now on Github.