If the office of the judge of high court is vacant at any time or a judge is absent or unable to perform his duties due to any reason, or there is a need to increase the number of judges of a high court, the president may appoint a person as an additional judge of the high court for such a period as the president may determine. But his period cannot exceed the period prescribed by law. The person so appoints should be otherwise qualified to be appointed as the judge of high court. (Art. 197)