In all counties in the state now or hereafter having a population of more than 150,000 and wherein regular terms of the district court are held in three or more places, the court administrator of the district court therein, by an instrument in writing, under the court administrator’s hand and seal, and with the approval of the district judge of the judicial district in which said county is situated, or, if there be more than one such district judge, with the approval of a majority thereof, may appoint deputies for whose acts the court administrator shall be responsible, such deputies to hold office as such until they shall be removed therefrom, which removal shall not be made except with the approval of the district judge or judges. The appointment and oath of every such deputy shall be recorded with the court administrator.