No such bonds shall be issued in such a manner as to increase the indebtedness of the said city, but such bonds shall be sold as directed by the board of aldermen of such city, and the proceeds thereof shall be applied only to the payment and discharge of the judgment and decrees of any court for the payment of which the same may be issued, and such bonds so sold shall be delivered at the same time that the judgment and decrees aforesaid shall be paid and discharged.