If any work is to be done or improvement made the City may authorize the same by contract. In the case of such contracts involving an expenditure of less than the amount specified in Section 228 of the Charter the appropriation authorizing the expenditure for such purpose shall be sufficient authority to execute the contract. If the amount involved is the amount specified in Section 228 of the Charter or more, the contract shall be authorized by ordinance of Council and one or more contracts may be executed under authority of the same ordinance.
(1952 Code § 3-9-27)