An additional executive department is hereby created in and for cities of the second class, to be known as the Art Commission, the members of which shall be appointed by the mayor, by and with the advice and consent of the select council, and who shall hold office during the term for which the mayor shall have been elected and until their successors shall be respectively appointed and qualified. In addition to the mayor and the director of the Department of Public Works, who shall be members ex officio the Art Commission shall consist of one painter, one sculptor, three architects, all of whom shall be eminent in their respective professions, and two others, neither of whom shall be a painter, a sculptor, or architect, and all of such appointed members shall serve without compensation; and, in case any vacancy shall happen among them, such vacancy shall be filled by the mayor, for the unexpired term. The Art Commission shall elect a president and secretary, whose term of office shall be for one year. They may employ clerks and other persons, whose salaries and wages, together with the other necessary expenses of the commission, shall be provided for, in the discretion of councils, by the proper appropriations and ordinances. A majority of the seven appointed members shall constitute a quorum for the transaction of any business or the decision of any matters within the competence or jurisdiction of the commission, and the majority of such quorum may decide; and the commission shall have the power to adopt its own rules of procedure, not inconsistent with any law or ordinance, and so that in proper cases reasonable notice and full opportunity to be heard shall be afforded according to the principles of the common law.