It is a historical fact, proven by all time and experience, that man has made progress toward his present civilized state only in proportion to his ability to develop tools of production, wherewith to subdue his unfriendly environment and to provide the comforts of life. We recognize this in a general way when we speak of the Age of Stone, Age of Bronze, and the Age of Iron and Steel, while the full realization that this is true, and that all physical, mental, and moral development depend very greatly upon the industrial background, has created a new and deep interest in industry and its relation to human progress. The development of simple tools into complex structures to replace manual labor has been a comparatively recent one, and the present civilization has been so affected by the work of the mechanic and the engineer that the past and present century might well be called the Age of Machinery.