Whenever any city of the second class shall have heretofore established a hospital in such city and issued bonds pursuant to the provisions of Kan. Stat. Ann. §§ 14-636 and 14-637, the governing body of such city may levy annually a tax for the purpose of equipping, maintaining and improving such hospital on all taxable tangible property within the limits of said city and to pay a portion of the principal and interest on bonds issued by such city under the authority of Kan. Stat. Ann. § 12-1774, and amendments thereto.