Synthesizing a Panoramic Scene with a Common Exposure via the Simultaneous Registration of Images

An engine coolant system contains a thermostat in a horizontally disposed line from the engine and a horizontally disposed air vent or bypass passage located above the thermostat to bleed air from the system. The bypass system contains a buoyant valve having a duckbill-like shape that pivots to one position by buoyancy in response to coolant flow to seal an air vent opening to the radiator, or to a return non-buoyant position permitting the bleed of air; one embodiment providing a valve with a buoyant insert as well as a weight insert; a second embodiment consisting entirely of a material buoyant in the conventional engine coolant.