Section 1. Be it enacted, &c., That in the payment or exchange of the street and temporary loan bonds, to be retired under the provisions of the act to which this is a supplement, the councils of the cities of the second class shall have full power to adjust the interest to the date of the maturity of such bonds, and the amount of money necessary for that purpose shall be payable either out of the proceeds of said bonds, or out of any funds in the treasury of any such city, over the investment of which said councils may have control, or in such other manner as said councils may direct.