According to their [Newton and his followers] doctrine, God Almighty wants to wind up his watch from time to time: otherwise it would cease to move. He had not, it seems, sufficient foresight to make it a perpetual motion. Nay, the machine of God's making, so imperfect, according to these gentlemen; that he is obliged to clean it now and then by an extraordinary concourse, and even to mend it, as clockmaker mends his work.

What is there about fire that's so lovely? ... It's perpetual motion; the thing man wanted to invent but never did. Or almost perpetual motion. ... What is fire? It's a mystery. Scientists give us gobbledegook about friction and molecules. But they don't really know.
[Fahrenheit 451 refers to the temperature at which book paper burns. In the short novel of this title 'firemen' burn books forbidden by the totalitaran regime.]