Annual report submitted by the Boy Scouts of America to Congress describing highlights from 1936, activities, service reports, honors, finance, organizational leadership, and other information about scouting programs.

Report presents the results of a photographic study of the combustion in a spark-ignition engine using both Schlieren and flame photographs taken at high rates of speed. Although shock waves are present after knock occurs, there was no evidence of any type of sonic or supersonic compression waves existing in the combustion gases prior to the occurrence of knock. Artificially induced shock waves in the engine did not in themselves cause knock.