XVIII. Persons employed in any of the offices to which these rules are applicable may be transferred without examination from one office to a grade no higher in another office, with, the consent of the heads of the respective offices and the approval of the Secretary of the Treasury. XIX. Under the provisions of rule 2[32] of August 5, 1873, and the operation of these regulations, the power of suspension and of recommendation for discharge from the service shall remain with the nominating officer unrestricted. If, however, in his judgment it be deemed advisable, he may direct any person in his department to be cited before the regular examining board, and such board shall examine into and report upon the qualifications, efficiency, and general fitness for the position held, or for any position in the same or a lower grade, of the person so cited to appear; and furthermore, any person in the service engaged in active outdoor duties may be cited to appear before a surgeon of the United States Marine-Hospital Service and be examined by such surgeon as to the physical abilities of such person to perform the duties of the position occupied or of a position of less exposure, if otherwise qualified. XX. The sessions of the examining boards shall not be open to the public, but the board of revision and appeal may select such number of prominent citizens as may be deemed advisable, who shall have free access to the examining rooms, and who shall take no part in the conduct of the examination, but may, by inspection and inquiry, assure themselves regarding its thoroughness and impartiality, and may publicly certify the results of their inspection. [Seventh rule for the civil service under the Executive order of April 16, 1872.[33]] The appointment of all persons entering the civil service in accordance with these regulations, excepting persons appointed by the President by and with the advice and consent of the Senate, postmasters, and persons appointed to any position in a foreign country, shall be made for a probationary term of six months, during which the conduct and capacity of such persons shall be tested; and if at the end of said probationary term satisfactory proofs of their fitness shall have been furnished by the board of examiners to the head of the Department in which they shall have been employed during said term, they shall be reappointed. [Fourth regulation for the civil service under the Executive order of April 16, 1872[34]] The appointment of persons to be employed exclusively in the secret service of the Government, also of persons to be employed as translators, stenographers, or private secretaries, * * * may be excepted from the operation of the rules. [Ninth rule for the civil service under the Executive order of April 16, 1872. [35]]