No money shall be drawn from the Treasury, nor shall any obligation for the expenditures of money be incurred, except pursuant to appropriations made by Council.
   The Director of Finance and/or the Mayor shall have the power to require evidence that the amount of each claim is justly due and is in conformity to law and Municipal legislation relating thereto.  For that purpose they may summon before them any officer, agent of any department, or employee of any department of the Municipality, and examine him under oath or affirmation relative thereto.