PUBLIC LAWS-CH. 529-JULY 1, 1946 38 Stat. 99. 56 Stat. 54, 1002 "Contingent expenses, Department of the Interior"; books of reference, periodicals and newspapers; and special wearing apparel and equip- ment for protection of employees while employed; $826,750, of which not to exceed $52,500 may be expended for personal services in the District of Columbia. Mining experiment stations: For personal services, purchase of laboratory gloves, goggles, rubber boots, and aprons, maintenance, operation, and repair of motor-propelled passenger-carrying vehicles, and all other expenses in connection with the establishment, main- tenance, and operation of mining experiment stations, as provided in the Act of March 3, 1915 (30 U. S. C. 8), $1,430,615, of which not to exceed $47,500 may be expended for personal services in the District of Columbia. Metallurgical research and pilot plants: For all expenses necessary to enable the Bureau of Mines to conduct laboratory, pilot plant, and demonstration plant tests to establish methods for more effectively utilizing the mineral resources in the United States and its possessions, including the lease of lands or buildings; research on and development of processes for production and utilization of metals and nonmetallic minerals; construction of buildings to house laboratories, pilot plants, and demonstration plants; operation, maintenance and repair of pas- senger automobiles; purchase of books, periodicals, and newspapers; and other items otherwise properly chargeable to the appropriation "Contingent expenses, Department of the Interior"; and not to exceed $30,000 for personal services in the District of Columbia; $1,000,000: Provided,That the Director of the Bureau of Mines, for the purposes of this appropriation, is authorized to accept lands, buildings, equip- ment, and other contributions from public or private sources and to prosecute projects in cooperation with other agencies, Federal, State, or private. Buildings and grounds, Pittsburgh, Pennsylvania: For care and maintenance of buildings and grounds at Pittsburgh and Bruceton, Pennsylvania, including personal services, operation, maintenance, and repair of passenger automobiles, and all other expenses requisite for and incident thereto, including not to exceed $36,270 for additions and improvements, $198,000. Economics of mineral industries: For investigations, and the dis- semination of information concerning the economic problems of the mining, quarrying, metallurgical, and other mineral industries, with a view to assuring ample supplies and efficient distribution of the min- eral products of the mines and quarries, including studies and reports relating to uses, reserves, production, distribution, stocks, consump- tion, prices, and marketing of mineral commodities and primary products thereof; preparation of the reports of the mineral resources of the United States, including special statistical inquiries; purchase of furniture and equipment; stationery and supplies; newspapers; travel expenses; operation, maintenance, and repair of motor-propelled passenger-carrying vehicles; and for all other necessary expenses not included in the foregoing, $850,000, of which not to exceed $727,500 may be expended for personal services in the District of Columbia. Construction and equipment of helium plants: The unobligated balance of the funds appropriated under this head in the Interior Department Appropriation Act, 1943, as supplemented in the Second Supplemental National Defense Appropriation Act, 1943, is hereby continued available until June 30, 1947. Helium utilization and research: For all expenses necessary to conduct inquiries and scientific and technologic investigations con- cerning resources, production, repurification, storage, and utilization of helium, independently or in cooperation with other agencies, public 374 [60 STAr.