In counties having a population of more than 500,000 the county treasurer, the register of deeds, the coroners and the drain commissioner shall and are hereby authorized to appoint a chief deputy, and all other deputies, clerks and employes employed in the departments of each of the said officers. The number and salaries of the said deputies, clerks and employes herein provided for shall be fixed in the same manner as they are fixed for deputies, clerks and employes of the other departments of the county government. The salaries of such deputies, clerks and employes shall be payable in the same manner and at the same time that other county employes are paid.