A Photograph a Week by John Francis

Spring Motor
A spring-driven motor designed by Leonardo da Vinci. The mechanism compensates for the decreasing power of the spring (inside the large drum) by means of a cone-shaped gear.	Camera: Pentax K10D + AF-540FGZ Lens: Pentax DA* 16-50mm/f2.8 Focal Length: 31mm Exposure: 1/50s Aperture: f/8.0 Sensitivity: ISO 400