The City Council shall not allow any rebate on the payment of city taxes in order to accelerate payment of same. If, however, the taxes are slow coming in and the council should find itself with insufficient funds after the beginning of the fiscal year to provide for the budget appropriations temporarily, then the council shall have the right to make short term notes and borrow a sufficient amount of money, at the lowest rate of interest obtainable, for the short period of time that may elapse until the tax payments shall be adequate to meet the budget appropriations; said loan to be retired out of the tax collections as soon as practicable.