There are authorized to be appropriated out of any moneys in the Treasury not otherwise appropriated, such sums as may be necessary for carrying out the provisions of this chapter; and the Secretary of Agriculture is authorized, within the limits of such appropriations, to appoint, remove, and fix the compensations of such officers and employees, not in conflict with existing law, and make such expenditures for rent outside the District of Columbia, printing, telegrams, telephones, law books, books of reference, periodicals, furniture, stationery, office equipment, travel, and other supplies and expenses as shall be necessary to the administration of this chapter in the District of Columbia and elsewhere.