General view of the carbon dioxide regenerator at the Fixed Nitrogen Research Laboratory's Urea Plant. In the production of fertilizer, liquid carbon dioxide and liquid ammonia are commonly combined under high-pressure…

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 the exterior of the water gas generator at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The term "water gas" commonly refers to the mixture of…

General view of V.L. Gaddy demonstrating use of compressors at the Fixed Nitrogen Research Laboratory's Urea Plant. In the production of fertilizer, liquid carbon dioxide and liquid ammonia are commonly combined under…

General view of the exterior of the Fixed Nitrogen Research Laboratory's Urea Plant, showing assorted apparatus and equipment used to produce Urea, a water-soluble powder form of carbonic acid frequently used as a…

General view of Dr. J.G. Thompson (left) and Mr. C.L. Sullivan (right) operating a hydrogen burner during the production of the hydrogen-nitrogen mixture used in the synthesis of ammonia at the U.S. Department of…

General view of Dr. J.G. Thompson demonstrating use of an ammonia catalyst fusion pot at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research…

General view of Mr. C.M. Sullivan (left) and Mr. P.N. Tierney (right) with an iron burner used for the preparation of ammonia catalysts at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located…

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 an apparatus used to study the thermal dissociation of sodium cyanide at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. Thermal dissociation is…

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…

General view of Dr. C.D. Garby demonstrating an apparatus used to study the formation of nitric oxide in flames at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.
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General view of Dr. E.W. Guernsey demonstrating an apparatus used to study the formation of nitric oxide in the explosion of carbon monoxide and oxygen at the U.S. Department of Agriculture's Fixed Nitrogen Research…

General view of an apparatus used to study the absorption of nitrogen oxides by silica gel at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen…

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 thermostat apparatus used to measure rates of reaction at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory…

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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Diagram of an apparatus used to determine nitrogen in the presence of hydrogen. Several component parts of the apparatus are labelled, including a circulating device, combustion tube, and topler pump. The diagram itself…

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 an apparatus used to make nitric acid from nitrogen dioxide at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory…

General view of an apparatus used to remove carbon dioxide from water gas, a mixture of carbon monoxide and hydrogen, at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington,…

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 an apparatus used to make urea from ammonium carbamate briquettes at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. Urea is a water-soluble powder…

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…