The city treasurer shall, as school treasurer, secure and safely keep all school moneys and shall maintain a separate bank account for capital project funds and process only transactions related to capital projects through those accounts, subject to the control and direction of the board, provided that the amount of interest or other investment earnings in such accounts may be from time to time withdrawn by the board and any amounts so withdrawn by the board may be used for any lawful purpose. He shall, subject to the limitations in this Article, keep his books and accounts concerning such moneys in the manner prescribed by the board. His books and accounts shall always be subject to the inspection of the board, or any member thereof. He shall at the end of each month, and oftener if required, render under oath an account to the board showing the state of the school treasury at the date of the account and the balance of money in the treasury. He shall accompany such accounts with a statement of all moneys received into the school treasury, and on what account, together with all warrants redeemed and paid by him; which warrants and all vouchers held by him shall be delivered to the business manager of the board and filed with his account in the business manager’s office upon every day of such settlement. He shall return all warrants paid by him stamped or marked “Paid”. He shall keep a register of all warrants redeemed and paid, which shall describe such warrants and show the date, amount, number, the fund from which paid, the name of the person to whom and when paid.