heat engine

For instance, if you have this general statement that perpetual motion machines are impossible, you can combine it with other statements about other tasks being possible or not and work out that a heat engine is possible.

The research might one day lead to improved efficiency of microscopic heat engines and motors.

The efficiency of any form of heat engine is determined by the power obtained from a certain fuel consumption.

You have to have a fall of temperature to run any kind of heat engine.

But during the centuries of experiments with a "heat-engine," the political world had greatly changed.

Considered as a heat engine, the gas engine is now twice as efficient as the very best modern steam engine.

Thus it appears that we have been able to show by very definite experimental evidence that the radiometer is a heat engine.