Hence in the productive force of machinery we see the material cause of the violent oscillations, the quiver of which never has time to pass out of modern trade.

The periodic over-production and subsequent depression are thus closely related to machinery.

It is the result upon the workman of these fluctuations that alone concerns us.
The effect of machinery upon the regularity of employment is both a difficult and a serious subject.

Its precise importance cannot be measured.

Before the era of machinery there often arose from other reasons, especially war or failure of crops, fluctuations which worked most disastrously on the English labourer.