The state legislature shall establish a nonpartisan board to be known as the state board of correction, and to consist of three members appointed by the governor, one member for two years, one member for four years, and one member for six years. After the appointment of the first board the term of each member appointed shall be six years. This board shall have the control, direction and management of the penitentiaries of the state, their employees and properties, and of adult felony probation and parole, with such compensation, powers, and duties as may be prescribed by law.