The board of state tax commissioners, created under the laws of this state, together with the governor, shall ex officio, constitute a state board of assessors, 1 of whom shall be elected chairman of said board. The secretary of the board of state tax commissioners shall be ex officio secretary of the state board of assessors without extra compensation, and shall keep a record of all its proceedings in addition to such other duties as may be required of him by said board, and shall devote his whole time to the duties of his office. In addition to the secretary, said board may employ such other clerical assistance as may be necessary and required to perform the duties imposed upon it by this act.