§ 653. Part time deputy sheriffs. Within the limits of the appropriation, the sheriff may employ such number of part time deputies, as he may deem necessary, who shall be paid a salary or on a per diem basis as the board of supervisors may determine. Such deputies shall be appointed in the same manner as regular deputies and shall perform only those duties and powers authorized by such sheriff. Whenever deemed necessary, a sheriff may deputize persons to serve civil process and execute civil mandates.