Reginald Mitchell's death at just 42, soon followed by the defense of Britain by pilots flying his finest creation, the Spitfire, elevated him to legendary status. He spent his whole career as a designer with Supermarine, whose products came from his pen or those that worked under him. Histories focus on the successful aircraft; those that failed to make the grade tend to be glossed over. But beyond this is a large body of concepts, early designs...