Centennial Museum gecko logo

Desert Diary


Many old engines used a mechanical governor to keep the speed of an engine within a narrow range as varying loads challenged it. The governor decreased fuel availability when the engine ran fast under a light load and increased it if the engine slowed down under a heavy load. The system was simple: levers connected weights to the throttle and a spinning axis. The operator set the original fuel feed. Thereafter, centrifugal force moved the weights upward toward the horizontal if speed increased, decreasing the amount of fuel available; and downward toward the vertical if speed decreased, opening the throttle. The result? An engine that maintained its speed within narrow limits regardless of its load.

Our bodies have many such systems maintaining critical conditions within narrow limits. The cooling system that allows us to function in the desert is one of these. Heat sensors alert the brain as our temperature climbs and sweat glands go to work. As the body temperature drops, sensors act to tone down the cooling mechanisms until sped up once again by climbing temperatures.
pen and ink

Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.


Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.