Section 2. The state auditor shall appoint a first deputy auditor who shall perform such duties as may be assigned him by the auditor and who may be removed by him for cause at any time. If, by reason of sickness, absence or other cause, the auditor is temporarily unable to perform the duties of his office, the first deputy shall perform the same until such disability ceases. In the event of a vacancy in the office of auditor, the first deputy shall be continued in office and shall perform all statutory duties of the auditor until an auditor shall be duly qualified. The first deputy shall give bond to the commonwealth for the faithful discharge of his duties, in a sum not exceeding five thousand dollars.