The surveyor so appointed shall receive compensation for his time actually employed, not to exceed 5 dollars per day and his necessary expenses for chain men and assistants, to be approved by the commissioner of the state land office. The surveyor's bills for services and expenses shall be made on forms furnished by the commissioner of the state land office, and itemized and sworn to, and shall be audited by the board of state auditors, and when allowed by them, shall be paid out of the general fund.