63 STAT.] 81ST CONG., 1ST SESS.-CH. 151-MAY 31, 1949 all property, materials, buildings, or structures disposed of pursuant to this subsection. SEC. 5 . Such sums as are necessary to carry out the purposes of this joint resolution are hereby authorized to be appropriated, and shall remain available until expended; except that upon the termination of the Commission any unexpended or unobligated balances shall be covered back into the Treasury of the United States. The appropria- tion authorized by this joint resolution shall be available for the operation of the building or buildings, structure or structures, im- provement or improvements, including light, heat, water, gas, janitor, and other required services; for the rental of space in the District of Columbia; for the selection, purchase, preparation, assembling, trans- portation, installation, arrangement, repair, safekeeping, exhibition, demonstration, and return of such articles and materials as the Com- mission may decide shall be included in Government exhibits; for the purchase of uniforms; for the compensation of the Director, and other officers and employees of the Commission in the District of Columbia and elsewhere; for actual and necessary traveling, hotel, and other expenses incurred by the Commissioners, the Director, and other officers and employees of the Commission in the discharge of their duties under this joint resolution; for telephone service; for the purchase or rental of furniture and equipment (including typewrit- ing and other office machines), stationery and supplies, maps, reports, documents, plans, specifications, manuscripts, newspapers, and all other appropriate publications: Provided, That payment for tele- phone service, rents, subscriptions to newspapers and periodicals, and other similar purposes, may be made in advance; for the hire and operation of passenger-carrying automobiles in the District of Colum- bia; for printing and binding to be done, in the discretion of the Commission, by establishments other than the Government Printing Office; for entertaining of distinguished visitors; and for all other expenses as may be deemed necessary by the Commission to fulfill properly the purposes of this joint resolution: Provided further, That all purchases, expenditures, and disbursements of any moneys made available by authority of this joint resolution shall be made under the direction of the Commission in accordance with law. All accounts and vouchers covering expenditures shall be approved by the Director or by such assistants as the Commission may designate, except for such allotments as may be made to the various executive departments, independent offices, and establishments, or the District of Columbia Government for direct expenditure; but these provisions shall not be construed to waive the submission of accounts and vouch- ers to the General Accounting Office for audit. SEC. 6 . Upon request of the Commission, the Director of the Bureau of the Mint is authorized to cause to be issued an appropriate medal commemorating the celebration of the sesquicentennial hereby author- ized, which medal shall be sold to the public by the Commission at such price as may be determined by it: Provided,That all revenues received by the Commission from such source shall be covered into the Treasury of the United States to the credit of the appropriation to be made pursuant to the authority contained herein and may be expended and shall be accounted for in the same manner as other funds authorized for expenditures by the Commission. The Director of the Bureau of the Mint is further authorized to cause to be issued badge medals in such quantity as the Commission shall determine, to be awarded to individuals or organizations in recognition of their participation in the celebrations hereby authorized, or for other out- standing service. The Commission shall reimburse the Bureau of the Mint for the cost of the medals and emblems. 143 Appropriation au- thorized. Post, p . 872. Availability of ap- propriation. Issuance of medals.