Scientific investigation is rapidly putting at our disposal vast amounts of knowledge concerning materials and forces, which it is the business of the engineer to utilize for the benefit of the community. Well-designed plants and efficiency labor-saving devices, to be seen on every hand, bear testimony that he is doing at least a portion of his work well. When, however, it comes to the operation of these plants and the utilization of these labor-saving devices, the lack of co-operation between employer and employee, and the inefficient utilization of labor, very much impair their efficiency. The increase of this efficiency is essentially the problem of the manager, and the amount to which it can be increased by proper study is, in most cases, so great as to be almost incredible.