There shall be appointed by the Board of Commissioners each year a certified public accountant or licensed public accountant, who shall make a full and complete audit of all books and accounts of the City of Alamo and of its departments, and shall make a complete report of said audit to the Board of Commissioners to be filed by it and to be open for inspection to the public as a public record, said auditor to be paid such compensation as may be fixed by the Board of Commissioners.