Letter from the United States Tariff Commission transmitting in compliance with the request of the Senate Committee on Commerce, dated May 3, 1918, a report upon the policy of establishing free zones in ports of the United States, together with an analysis and comment concerning the bill (S. 4153) to provide for the establishment, operation, and maintenance of free zones in the ports of the United States, and for other purposes, as introduced in the Sixty-fifth Congress.