As soon as may be after this Division becomes applicable to a county with a population under 1,000,000, the judges of the Circuit Court of the circuit in which the county is located shall, by a majority vote of the entire number of those judges, appoint to the office of Public Defender a properly qualified person, who shall hold office, his death or resignation not intervening, at the pleasure of the judges competent to appoint. Whenever a vacancy occurs in the office it shall be filled in the same manner, and the person appointed to fill the vacancy shall have the same tenure of office.