"Section 271.    Leave of absence of Judges of First Instance. — During the yearly court vacation, the judges of first instance not specially assigned to vacation duty shall be upon vacation leave. In case of those who are assigned to vacation duty, they shall be entitled to vacation leave at any subsequent time for the same number of days that they spend on vacation duty but not exceeding one month per year, said leave being cumulative; but the total amount of leave that can accumulate to the credit of a judge of first instance at any one time shall not exceed ten months, which said judge may enjoy, including the one month of court vacation or the one month's leave in lieu thereof, if, in the opinion of the Department Head, the exigencies of the service permit."