this contemporaneous production that his subsistence is drawn.
The fifty square miles of London undoubtedly contain more wealth than within the same space anywhere else exists. Yet were productive labor in London to absolutely cease, within a few hours people would begin to die like rotten sheep, and within a few weeks, or at most a few months, hardly one would be left alive. For an entire suspension of productive labor would be a disaster more dreadful than ever yet befel a beleaguered city. It would not be a mere external wall of circumvallation, such as Titus drew around Jerusalem, which would prevent the constant incoming of the supplies on which a great city lives, but it would be the drawing of a similar wall around each household. Imagine such a suspension of labor in any community, and you will see how true it is that mankind really live from hand to mouth; that it is the daily labor of the community that supplies the community with its daily bread.
Just as the subsistence of the laborers who built the Pyramids was drawn not from a previously hoarded stock, but from the constantly recurring crops of the Nile Valley; just as a modern government when it undertakes a great work of years does not appropriate to it wealth already produced, but wealth yet to be produced, which is taken from producers in taxes as the work progresses; so is it that the subsistence of the laborers engaged in production which does not directly yield subsistence, comes from the production of subsistence in which others are simultaneously engaged.
If we trace the circle of exchange by which work done in the production of a great steam engine secures to the worker bread, meat, clothes and shelter, we shall find that though between the laborer on the engine and the producers of the bread, meat, etc., there may be a thousand intermediate exchanges, the transaction when reduced to its lowest terms, really amounts to an exchange of labor between him and them. Now the cause which induces the ex-
