In addition to all other taxes now or hereafter authorized by law, the court of county commissioners, board of revenue, or like governing body of Winston county shall have the power to levy and collect, for a period not exceeding twenty years, a special ad valorem tax on property situated within said county, at a rate of five mills on each dollar of property as assessed for state taxation for the preceding year, the proceeds of said tax to be used solely for acquiring, by purchase, lease, or otherwise, constructing, operating, equipping, or maintaining county hospitals or other public hospitals, nonprofit hospitals, and public health facilities. Provided, the question of levying the tax, the purpose thereof, and the time such tax is proposed to be continued shall have been first approved by a majority of the qualified electors of Winston county voting at a referendum to be held for that purpose. The referendum shall be held on the same day as the first countywide primary, general, or special election held in the county after the ratification of this amendment. The board of revenue, court of county commissioners or like governing body of the county shall order and provide for holding the referendum on such date.