Whenever any power is vested in or any duty required of the Mayor, it is deemed to extend to and embrace and may be exercised by the acting Mayor or Mayor pro tem unless such construction contrary to the provisions of this code or the terms of the ordinance vesting such power or requiring such duty. The City Council shall select one of its members as Mayor pro tem. If a temporary absence or disability of the Mayor incapacitates him from the performance of his duties but does not create a vacancy in the office, the City Council shall elect one of its members to be Mayor pro tem. The Mayor pro tem, during this absence or disability, shall perform the duties and possess all the rights and powers of the Mayor. In the absence of the Mayor, acting Mayor, or Mayor pro tem, the City Council may elect an Alderman to act as a temporary chairman. He shall have only the powers of a presiding officer and a right to vote in his capacity as Alderman on any ordinance, resolution, or motion.
(‘69 Code, § 2-107)