The economy of human time is the next advantage of machinery in manufactures.

At each increase of knowledge, as well as on the contrivance of every new tool, human labour becomes abridged.

In turning from the smaller instruments in frequent use to the larger and more important machines, the economy arising from the increase of velocity becomes more striking.

The fatigue produced on the muscles of the human frame does not altogether depend on the actual force employed in each effort, but partly on the frequency with which it is exerted.

Whenever the work is itself light, it becomes necessary, in order to economize time, to increase the velocity.

A powerful attraction exists, therefore, to the promotion of a study and of duties of all others engrossing the time most completely, and which is less benefited than most others by any acquaintance with science.