No contract shall be made by Council or by any committee or member thereof, and no expense shall be incurred by any officer or department of the City, whether or not the object of the expenditure has been ordered by Council, unless an appropriation has been previously made concerning such contract or expense. Any contract made or expense incurred in violation of this section shall be null and void as to the Municipality, and no money belonging thereto shall be paid on account thereof. However, pending the passage of the annual appropriation ordinance for any fiscal year, Council may authorize department heads or other separate agencies of the Municipality to make necessary expenditures for the support thereof upon the basis of the appropriations for the preceding year.
(1942 Code Chap. XVI, Sec. 4)