I. Impact of transport technology upon the United States economy, 145. — II. Costs of air transport, 149. — The rôle of aircraft in the future transport web, 153. — Private aircraft, 156. — Cargo movement, 157. — III. Implications of the foregoing: urban-metropolitan patterns, 161; investment outlets, 163; trade channels and commercial centers, 164; capital exports, 166; government aid, 166. — Appendix: the case of Brazil, 168.