Section 4
SEC. 4. A sinking fund is hereby created for the payment of the bonds issued under the provisions of this Act, in such a manner that the total amount thereof at each annual due date of the bond issued shall be equal to the total of an annuity of such a sum, for each million pesos of bonds outstanding, as with interest at the rate of three and one-half per centum per annum shall be sufficient to retire said bonds at maturity. Such sinking fund shall be under the custody of the Treasurer of the Philippine Islands, who shall invest the same, in such manner as the Secretary of Finance may approve in accordance with the provisions of Act Numbered Three thousand fourteen governing the investment of sinking funds, and shall charge all expenses incidental to such investment, to the said sinking fund.