15. Meetings of Board   (1) The Board shall meet at least once every quarter and so often as may be necessary. (2) All members of the Board shall be given seven clear day's notice of a meeting specifying the date and time and place of the meeting and business to be transacted thereat; Provided that seven clear days' notice shall not be necessary where in the opinion of the chairman, business of an emergent nature has to be-transacted.