Balanced inside a single towering wheel, the inventor grips a steering wheel and leans forward as if coaxing his machine into motion. The D’Harlingue Monowheel looks part bicycle, part aircraft experiment: an open metal framework, a large perforated rim, and a compact engine assembly mounted to one side with a propeller-like element. Beneath the rider, small stabilizing wheels and struts hint at the constant struggle to keep such a bold design upright and controllable.
What makes this 1917 invention so compelling is its fearless reimagining of personal transportation at a moment when engineers everywhere were pushing beyond familiar forms. Instead of two wheels and a frame, the entire vehicle becomes a rolling ring, with the operator perched within its circle—an arrangement that promises agility while raising practical questions about balance, braking, and safety. The photograph invites close inspection of the mechanics: rods, braces, and drive components arranged like a skeletal prototype, emphasizing experimentation over polish.
Collectors of early automotive history and unusual motorcycle designs will recognize the monowheel as one of those ideas that refused to stay on the drafting table. Its presence alongside the inventor turns the scene into a quiet statement about ingenuity—an era when mechanical progress often arrived through daring, sometimes awkward, attempts like this. For readers searching for rare inventions, monowheel vehicles, or 1910s engineering curiosities, this image offers a vivid glimpse into the adventurous spirit of early motorized innovation.