Two views of the No. 2 experimental blast furnace at a U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant. The individuals visible in the first photograph are identified (left to right) as Reilly; Royster; Hignett; Whitlow; and Clark. The individuals visible in the second photograph are identified as Clark (left) and Whitlow (right).

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in 1919 under the directorship of Arthur B. Lamb. Initially part of the War Department, the F.N.R.L. was the successor to several wartime initiatives to develop a secure domestic supply of nitrate compounds necessary for the manufacture of explosives during World War I. With a staff of about 110 individuals, including 35 to 50 chemists, the F.N.R.L. focused on the manufacture, production, and development of products of atmospheric nitrogen, including munitions and fertilizers.