“Our knowledge of the properties and laws of physics shows no signs of approaching its ultimate boundaries. . . This increasing physical knowledge is now, rapidly converted by practical ingenuity, into physical power. . . . From this union of conditions, [we can] forward to a vast multiplication and long succession of [mechanical] contrivances for economizing labor and increasing its produce: and to an ever wider diffusion of the use and benefits of those contrivances.” John Stuart Mill, British liberal political philosopher, Principles of Political Economy with Some of Their Applications to Social Philosophy, 1849

explain one way in which mill's prediction accurately described subsequent developments in the late nineteenth century