Section 1. Section one of Act Numbered Thirty-five hundred and ninety-two is hereby amended to read as follows:
"SECTION 1. All wharfage fees collected from the date on which this Act takes effect, under the provisions of section fourteen of the Tariff Law of nineteen hundred and nine, shall be deposited in the National Treasury and shall form a special fund to be known as "Port Works Fund," which shall be disbursed in accordance with acts of the National Assembly for the investigation, construction, improvement and maintenance of ports, buoys, lighthouses, and other aids to navigation, and for airports and landing fields, including the purchase and maintenance of necessary equipment: Provided, however, That fifty per centum of the fund so formed is hereby set aside for the necessary expenses of maintenance of ports, buoys, lighthouses, and other aids to navigation and for airports and landing fields belonging to the National Government, or constructed by authority of the National Assembly, including dredging and improvements incidental to such maintenance, to be allotted by the Secretary of Public Works and Communications, with the approval of the President, upon certification by the Secretary of Finance that the necessary funds are available: Provided, further, That out of the remaining fifty per centum of the fund so formed there is hereby set aside annually such sum as may be necessary to reimburse the general fund for the payment of interest charges on account of bonds issued by the National Government for the construction and improvement of ports."