The first fact which becomes apparent when economic progress is studied, is that static laws have a general application and are as efficient in a society which is undergoing rapid transformation as in one that is altogether changeless. Water in a tranquil pool is affected by static forces. Let a quantity of other water rush in and there are superinduced on these forces others which are highly dynamic. The original forces are as strongly operative as ever, and if the inflow were to stop, would again reduce the surface to a level. The laws of hydrostatics affect the waters in the rapids of Niagara as truly as they do those in a tranquil pool; but in the rapids a further set of forces is also operative. In the work referred to, issued in 1899, an effort was made to isolate the phenomena of Economic Statics and to attain the laws which govern them. Necessarily this study made a certain impression of unreality, since it put out of sight changes which are actually going on and are the conspicuous fact of modern life. It assumed the conditions of a world without any such movement and endeavored to formulate laws which, in such a condition, would fix standards of value, wages, interest, etc. It put actual changes out of sight, intentionally and heroically, but with a full recognition of the fact that they are actually taking place and must in due time be introduced and studied. We live in what is _par excellence_ an age of progress, and it is in part for the sake of perceiving the laws of progress that we first disentangle from them the laws of rest and make a separate study of these. The world from which change is excluded is unreal, but the _static laws_ which can be most clearly discerned by mentally creating such a world have reality. Every day's transactions are governed by them as truly as a physical element like water in active movement is affected by forces which, if they acted alone, would bring it to a state of permanent rest. The first purpose, therefore, of the present work is to show the presence and dominance in the real world of the forces described in the earlier work. It brings static laws into view and endeavors to show how they act at any one particular stage of industrial evolution. Even while changes are examined, the fact is perceived that there are steadily at work forces which, if changes should cease, would make society conform to a certain imaginary static model and makes wages and interest also conform to static standards.