"Pure Henry" explores the automotive engineering ingenuity of Ernest Henry, focusing specifically on the design, development, and racing records of his 5-liter, 3-liter, and 2-liter Ballot automobiles. Henry's designs were remarkable not only for their mechanical engineering performance but also for their critical contribution to the development of modern racing automobile engine designs. This book also celebrates the under-sung accomplishments of René Thomas, one of history's most winning and talented early auto racing drivers whose feats have gone largely unnoticed until recent years. "Pure Henry" also seeks to set the record straight as to the provenance of the few surviving Ballot cars that won some of the world's most prestigious racing events in the 1920s. By presenting scientifically-documented evidence, coupled with the historicity of the corresponding events and people involved, the author reveals the sometimes-complex process for determining the provenance of these rare gems of automotive masterwork. ( )