18. Chairman.-
(1) A member of every district board or local board shall be elected or appointed to be chairman of the board, and shall hold office for such term, not exceeding three years, as the Local Government may, by a rule made under this Act, fix. (2) The Local Government shall determine, as regards each board or as regards any class of boards, whether the chairman shall be a person appointed by virtue of his office or by name or be elected.