The Secretary of the Senate is on and after November 1, 1973, authorized to designate, in writing, employees of the Disbursing Office of the Senate to administer oaths and affirmations, with respect to matters relating to that Office, authorized or required by law or rules or orders of the Senate (including the oath of office required by section 3331 of title 5). During any period in which he is so designated, any such employee may administer such oaths and affirmations.