The national improvements connected with rivers and harbors were first political—­that is, they were for the use of the government’s navy; they became, secondly, commercial—­for the free use of all citizens engaged in trade; and they continue to unite these two characters.  Forestry is most largely undertaken in this country by the national government, partly because some forest areas in the West extend over state boundaries, and largely because large tracts of public forest lands were still unsold at the time public attention was attracted to the subject.  Since 1890, the policy of reserving great areas for forests, and picturesque districts for national parks, has developed greatly in the United States.  The national forest area contained in the various forests in 20 states (not including Alaska and Porto Rico), now covers about 225,000 square miles, equal in area to five states of the size of Pennsylvania.  There are, besides, fourteen large national parks, ranging in size from a few hundred acres up to over 2,140,000 acres (the area of the Yellowstone National Park), and aggregating 4,600,000 acres, nearly the size of Massachusetts or of New Jersey, besides numerous other national reservations for monuments and antiquities.

In some countries mines are thought to be peculiarly fitted for national ownership and control.  In the German Empire the several states own coal, salt, and other mines.  Coinage and banking are everywhere looked upon as functions of sovereignty, and yet it is no more necessary for a nation to own its own mint in order to control the monetary system than for it to print the banknotes in order to regulate their issue.  The American government has its own printing office.  The fish commission, and the various branches of the department, cooeperate with private industry in many ways.  This brief survey suggests that the industries undertaken by government are both varied in nature and large in extent, altho small in proportion to the mass of private industry.

Sec. 12. #Economic basis of public ownership#.  The question as to the proper limits of public ownership is one most actively debated.  The movement is progressing in accordance with the principle that public ownership is economically justified wherever it secures a product or service of widespread use that would otherwise be impossible, or insures the public a better quality or a lower price.  The question of public ownership is not exclusively an economic question.  There are incidental problems, such as its effects on enterprise and on political integrity, with which it is not possible here to deal.  In the main, however, public ownership is simply a business policy which must be justified by its economic results.  In the case of a general social benefit not to be secured without public ownership (as popular education or the climatic effect of forests), the only question to answer is whether the utility is worth the cost.  In the case of industries already in private hands,