=Future of Foreign Commerce.=—Ocean transportation has made enormous strides forward during the past twenty years. [Sidenote: What new inventions may do for trade.] Wireless communication now enables ships to keep in touch with each other and with the shore, thus making navigation safer. It has been demonstrated by naval experiments that great ships can be steered and their machinery controlled by radio apparatus in the hands of men several hundred miles away. Then there is the airship and the airplane, in both of which it has been shown to be possible to cross the Atlantic far above the surface without a stop. It seems to be beyond doubt that air carriers will, even within our own generation, be used to carry mail overseas as they are now being used on land, and probably passengers as well. The day may come when goods, also, will be ferried through the air from continent to continent in less than a single day. The march of invention in this as in other fields is so rapid that no one can tell today what the morrow may bring forth.[170] But of one thing we may be hopeful: that even as the era of rail transportation served to bring all parts of the country into more intimate relation, so may it come to pass that the world of the future will find all its distant parts brought into more friendly contact by the development of these twentieth-century miracles of rapid transit. =Commerce and Peace.=—Commerce between countries helps to promote international good-feeling and friendship. It is true that commercial rivalries have sometimes inspired international jealousy and have even paved the way to war; but legitimate trade, honestly carried on between nations, is far more likely to prove a means of drawing them together. From their commercial intercourse nations derive mutual profit. By trading with one another they learn to understand each other. Isolation makes for suspicion and war. World commerce makes for peace. General References H. G. SELFRIDGE, _The Romance of Commerce_, pp. 230-239; 318-349; C. F. CARTER, _When Railroads Were New_, pp. 33-74; E. R. JOHNSON and F. W. VAN METRE, _Principles of Railroad Transportation_, pp. 492-534; CLIVE DAY, _A History of Commerce_, pp. 485-517; 564-579; E. R. JOHNSON, _American Railway Transportation_, 2d ed., pp. 52-68; 367-385; ISAAC LIPPINCOTT, _Economic Development of the United States_, pp. 520-549; 611-634; F. W. TAUSSIG, _Principles of Economics_, Vol. I, pp. 508-545 (Protection and Free Trade); Vol. II, pp. 363-396 (Railway Problems); JAMES T. YOUNG, _The New American Government and Its Work_, pp. 119-140 (The Regulation of Commerce); 187-202 (Federal Power Over Interstate Commerce); W. B. MUNRO, _Government of the United States_, pp. 246-264 (The Commerce Power); H. R. BURCH, _American Economic Life_, pp. 273-296; C. R. VAN HISE, _Concentration and Control_, pp. 4-34; 170-192; I. L. SHARFMAN, _The American Railroad Problem_, pp. 100-186.