Group photograph of unidentified personnel from the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at…

Close-up view of molten slag emerging from the phosphoric acid furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The slag consists of waste produced during…

General view of the exterior of the gas storage facility at the Fixed Nitrogen Research Laboratory's catalyst testing plant. Two unidentified workers are visible on the right-hand side of the photograph. A sign reading…

General view of the general repair shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facilities located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

General view of apparatus use to determine total and partial vapor pressures at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The apparatus was commonly used to…

General view of a heat converter, interchanger, and condenser used for water-gas hydrogen production at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The term "water…

General view of a high-frequency apparatus used in the Fixed Nitrogen Research Laboratory's Arc Laboratory. In the early 20th century, the arc process, in which electric generators are used to combine nitrogen and…

General view of a high-pressure circulating pump used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

General view of a high-pressure pump used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at…

General view of a high-pressure pump used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at…

General view of high-pressure purification apparatus used at the Fixed Nitrogen Research Laboratory's catalyst testing plant.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in…

High-temperature vacuum furnace used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in 1919 under…

Two views of J.E. Reuter at work in the instrument shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and tools.

The Fixed Nitrogen Research Laboratory…

Two views of J.E. Reuter at work in the instrument shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and tools.

The Fixed Nitrogen Research Laboratory…

General view of J.F. Shultz demonstrating an apparatus used to analyze the effect of phosphine upon ammonia catalysts at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington,…

General view of acetylene welding at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The man visible in the photograph is identified as J.J. Connor. This photograph is…

General view of a laboratory at the Fixed Nitrogen Research Laboratory's catalyst testing plant. Various laboratory glassware and scientific apparatus are visible in the photograph, as well as a supply cabinet…

General view of a large-capacity constant temperature bath with a removable glass front used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen…

General view of the library at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American…

General view of the machine shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facilities located in Washington, D.C.

The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at…

General view of a metallic contact apparatus, likely used to measure electrical contact between metallic objects, at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.
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General view of a table-top model of a synthetic ammonia plant showing an assortment of plant machinery and apparatus. The model was created by the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory…

General view of the gas-fired smelting furnace used to volatilize (i.e. cause to evaporate or disperse in vapor) potash at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington,…

General view of Mrs. M.K. Murray demonstrating use of a nitrometer, an apparatus used to determine the amount of nitrogen or nitrogen compounds in a substance or mixture, at the U.S. Department of Agriculture's Fixed…

General view of machinery used to crush ore at the Fixed Nitrogen Research Laboratory's blast furnace plant. A worker identified as "Parker" is seen transferring raw material, presumably ore, from a machine into a…