§ 120-d. Officers of meeting. In order to facilitate business procedure, the local authorities of the several municipalities or districts meeting jointly for the purposes herein provided shall, at a meeting at which all the municipalities and districts intending to act jointly are represented, choose from among their number a chairman, who shall act as such until his successor is chosen in a similar manner. Such meeting, when organized, shall elect a secretary who may or may not be a member of one of the local boards meeting jointly.