An Act providing that a city of the first class shall sell bonds or other securities, except as provided herein, issued by it at public sale after not less than one public notice for such price, at, above or below their par value plus accrued interest, as shall be determined by the authorities of the city and providing that such a city may sell bonds or other securities at private sale when no conforming bid has been received at a prior public sale; and providing that the provisions hereof shall apply to all borrowings and the issuance of bonds or other securities therefor, whenever authorized.