DR. SCHNAUFFER presents in this paper the results of research on and measurements of combustion processes in internal-combustion engines by means of a slow-motion camera and a micro-chronometer. This method for flame-propagation indication depends on the physical property of flame to ionize air gaps and hence make them conductors of electric current. The recording equipment used is very simple, he says, and can be simplified still further if only visual inspection of the combustion processes is desired. He gives also a brief review of the history of combustion-process research, and a bibliography.
Using this method, all the conditions affecting the speed of flame-propagation in a high-speed spark-ignition engine were examined, and Dr. Schnauffer emphasizes that the results were accurate.
Neon lamps can be substituted for an oscillograph, if desired, and are less expensive; further, this makes possible the registration of an unlimited number of test points. An aviation-engine cylinder was investigated by inserting 24 measuring gaps distributed over the entire surface of the combustion chamber, and neon lamps were used. This set-up represented a cross-section of the combustion chamber on which, as the lamps were lighted, the course of flame-front travel could be followed. Dr. Schnauffer points out that this method should be of special interest to universities as a means of instructing students.