General view of the electron inertia apparatus 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 the electrical shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and apparatus. The man visible on the left-hand side of the photograph is…

General view of F.F. Robey at work in the carpenter shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and apparatus.

The Fixed Nitrogen Research Laboratory…

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…

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 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…

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 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 Mr. Merz using an apparatus to determine the hygroscopicity of fertilizer materials and mixtures at the the Arlington Experimental Farm in Arlington, Virginia. Established by an act of Congress in April…

General view of reaction bombs used at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory to test catalysts at 100 atmospheres of pressure. Numbers are visible on the exterior of the various…

General view of the repair shop at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory showing assorted machinery and apparatus.

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

Four stoppered jars containing samples of commercial fertilizer and concentrated fertilizer mixtures produced at the Arlington Experimental Farm in Arlington, Virginia. Established by an act of Congress in April 1900,…

View of a shaking machine designed at the Arlington Experimental Farm in Arlington, Virginia. Established by an act of Congress in April 1900, Arlington Farm served as the main field laboratory for the Bureau of Soils,…

General view of an apparatus used to facilitate the adsorption of silica gel and nitrogen oxide at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. Adsorption refers to…

View of a stirring machine designed at the Arlington Experimental Farm in Arlington, Virginia. Established by an act of Congress in April 1900, Arlington Farm served as the main field laboratory for the Bureau of Soils,…

General view of an apparatus used to study the Bucher Process for the fixation of nitrogen at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. Based on research…