W.E. Knowles Middleton, continuing his series of books on the history of the National Research Council of Canada, here presents a history of the challenges, defeats and triumphs of mechanical engineering at the Council. Throughout much of the history of the National Research Council, the Division of Mechanical Engineering has been mostly preoccupied with problems of aeronautics. During World War II the Division constituted an aeronautical laboratory. The influence of individuals, government departments, and individuals, all involved in supporting and demanding research into problems of mechanical engineering in Canada makes intriguing reading. The volume will be of interest to those investigating the history of science and technology in Canada. It will also be crucial to those interested in Canada's contribution to World War II on the fronts of technology and aeronautics.