The civil service commission shall consist of 3 members, 2 of whom shall be appointed by the board of supervisors, 1 to be appointed for 2 years and 1 to be appointed for 6 years. The third member of the commission shall be elected by the members of the sheriff’s department and he shall serve for a period of 4 years from the date of his appointment; a majority vote of the members of the sheriff’s department shall be necessary to select such member. Thereafter, all appointments shall be made for a period of 6 years each; each commissioner shall serve until his successor is appointed and qualified by the appointing power hereinbefore designated.

   The commission shall elect one of their number to act as president of the commission, who shall serve for 1 year.