At every annual general meeting the council shall elect a chairman and a vice-chairman from among their number and the persons so elected shall respectively hold office until the next ensuing annual general meeting.

If any vacancy occurs in the office of chairman or vice-chairman before the expiration of his term of office the council shall, as soon as possible, hold an ordinary meeting for the purpose of filling such vacancy.

The chairman or, in case of his absence, the vice-chairman or, if neither of them be present, some other member of the council, to be elected by the meeting, shall preside at all meetings of the council.