Popular Science Edition . — L. : House of Entertaining Science, 1939 - 7 s. : il. "Eternal engine" is such an imaginary machine that, without borrowing energy from outside, it would act non-stop and do some work at the same time. A machine that would support only its own motion, without producing any additional work, would not be an “eternal engine” in the strict sense of the word. It is impossible to implement a "perpetual engine" - this would be contrary to the laws of nature. You cannot create energy from nothing: energy is not created, but only converted from one kind to another. This is the basic law of all natural science, the law of conservation of energy, discovered in the middle of the last century by Julius Robert Mayer.