“In order to carry out the purposes of this Act [enacting this chapter] there is hereby authorized to be appropriated, out of any money in the Treasury not otherwise appropriated, the sum of (a) $750,000 for the erection and equipment of a building or buildings, including plumbing, lighting, heating, general service, and experimental equipment and apparatus, the necessary roads, walks, and ground improvement, and land for the site of the building if no land is donated; and (span) $250,000 annually for the maintenance and operation of the experimental station, including personal services, supplies, equipment, and expenses of travel and subsistence.”