The ships of the world use approximately 75,000,000 tons of coal annually. The opening of the Panama Canal will save several million tons a year and the money thus saved will, in part, fall into the coffers of Uncle Sam. A vessel en route from Chile to Europe can save nearly enough in the cost of coal alone to pay the tolls that will be exacted at Panama. When the United States came to frame its system of toll charges and collections, it was found that there was a wide difference of opinion as to the right of the United States Government to exempt coastwise shipping from the payment of tolls. Under the Hay-Pauncefote treaty with Great Britain there was also a wide variance of opinion as to the question of whether the United States, as a matter of national policy, ought to exempt from the payment of tolls, ships trading between its own ports on the two coasts. These questions were argued pro and con, and Congress finally decided by a very close vote that the United States ought to allow ships trading between its own ports to use the canal free of charge. No foreign ships are permitted under any circumstances to engage in such traffic. Those who advocated the exemption of ships trading exclusively between United States ports from the payment of tolls, did so on the ground that it would build up a wealthy American merchant marine which would be invaluable to the United States in time of war, and also that it would tend to reduce freight rates between Atlantic and Pacific points. They argued that every cent added to the cost of transportation through the canal would be reflected in freight rates between the East and the West. Those who opposed the exemption of American coastwise shipping from the payment of tolls, asserted that the coastwise shipowners already had a monopoly on the handling of cargo between American ports, and that no further encouragement was needed. They argued that it would make little or no difference in rates whether tolls were charged or not, and that the only people who would benefit would be the shipowners. They contended that the United States ought to charge everybody alike and use the tolls collected for the purpose of repaying the money it spent in building the canal. Some of them also contended that the Hay-Pauncefote treaty bound the United States to treat all shippers alike, and that the United States could not discriminate in favor of the American coastwise traffic without contravening the treaty with Great Britain. This view, however, did not prevail, and the law, as enacted, exempted coastwise shipping.