(a) Establishment: The Common Council shall act as and perform all the duties and exercise the power as a Board of Adjustment. The Mayor shall be Chairman of the Board of Adjustment as so composed. The concurring vote of at least two-thirds of the members of the board as so composed shall be necessary to reverse any order, requirement, decision or determination of any administrative official, or to decide in favor of the appellant on any matter upon which it is required to pass under any zoning ordinance or to effect any variation in such ordinance.
(b) Procedure: The Board of Adjustment shall adopt rules necessary to the conduct of its affairs and in keeping with the provisions of this ordinance. Meetings shall be held at the call of the Chairman and at such other times as the Board may determine. The Chairman, or in his absence the acting chairman, may administer oaths and compel the attendance of witnesses. All meetings shall be open to the public.