With any technology, there are certain inflection points when it goes from being something perpetually in the near future to being a part of everyday life.
He writhed under the jokes, practical and otherwise, which were perpetually made at his expense, and yet never ceased, it seemed wilfully, to expose himself to them.
He reasoned that as the wheels spun, the mercury would flow to the bottom of each reservoir, leaving one side of the wheel perpetually heavier than the other.
Such were the kind of lamentations resounding perpetually through Longbourn-house. Elizabeth tried to be diverted by them; but all sense of pleasure was lost in shame.