The said committees may meet from time to time, and may adjourn from place to place, as they think proper, for carrying into effect the purposes of their appointment; and no such committee shall excercise the powers intrusted to them except at a meeting at which there shall be present the prescribed quorum, or if no quorum be prescribed then a quorum to be fixed for that purpose by the general body of directors; and at all meetings of the committees one of the members present shall be appointed chairman; and all questions at any meeting of the committee shall be determined by a majority of votes of the members present, and in case of an equal division of votes the chairman shall have a casting vote, in addition to his vote as a member of the committee.