Two aerial views of the U.S. Department of Agriculture complex located in Washington, DC. The second photograph was taken during the construction of the Administration Building and East and West Wings. The in-progress…

General view of the blowing out process for the experimental blast furnace at a Fixed Nitrogen Research Laboratory facility. The process of blowing out, also known as "raking out," is undertaken when production from a…

General view of the M.V. "Triaster" motor ship being loaded with phosphate at the cantilever located in Christmas Island, Nauru. This ship was managed by the British Phosphate Commissioners, a board of representatives…

General view of the carbon tube precipitator and spray tower for the experimental blast furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen…

General view of Dick Adams 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…

General view of unidentified employees observing the temperature inside the Royster stoves at the Fixed Nitrogen Research Laboratory's experimental blast furnace plant during a Tennessee Valley Authority (T.V.A.)…

General view of unidentified employees opening the cinder-notch on the No. 2 experimental blast furnace on a burden (a load, especially a heavy one) of phosphate at the U.S. Department of Agriculture's Fixed Nitrogen…

General view of a worker emptying the slag ladle on the No. 2 experimental blast furnace on a burden (a load, especially a heavy one) of phosphate at the U.S. Department of Agriculture's Fixed Nitrogen Research…

Two views of apparatus and equipment used to produce an intermediate suitable for conversion to potassium metaphosphate at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington,…

U.S. Department of Agriculture exhibition display concerning fertilizer values as determined by per cent of plant food. The display includes several photographs of a range of agricultural crops, including wheat, cotton,…

General view of an experimental blast furnace at a U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant. The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in…

Two views of the No. 2 experimental blast furnace on a burden (a load, especially a heavy one) of phosphate at a U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant.

The Fixed Nitrogen Research…

Three views of the experimental blast furnace on a burden (a load, especially a heavy one) of phosphate at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant.

The Fixed Nitrogen Research…

Two views of the experimental blast furnace on a burden (a load, especially a heavy one) of phosphate at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant.

The Fixed Nitrogen Research…

Assorted views of the Fixed Nitrogen Research Laboratory's experimental blast furnace plant during a Tennessee Valley Authority (T.V.A.) operation.

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

General view of the exterior of the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory facility located at American University near Washington, D.C. The Fixed Nitrogen Research Laboratory (F.N.R.L.) was…

Group photograph of Fixed Nitrogen Research Laboratory personnel posed outside an unidentified facility. The Fixed Nitrogen Research Laboratory (F.N.R.L.) was established at American University in 1919 under the…

General view of the flushing of the No. 2 experimental blast furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C.

The Fixed Nitrogen Research Laboratory…

Two views of the No. 2 furnace and stock piles at a U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory plant. The stock piles likely contained a mix of raw material, including greensand, leucite, coke,…

Group photograph of unidentified female personnel at an unidentified United States Department of Agriculture facility. A large board bearing a sheaf of wheat is visible in front of the group.

Four views of the hearth and crucible of the No. 2 experimental blast furnace at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. The photographs show the hearth and…

Two views of the interior of the Engine Room at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory, with both full and partial views of the blowing engines for the experimental blast furnace.

The…

General view of the Engine Room at the U.S. Department of Agriculture's Fixed Nitrogen Research Laboratory located in Washington, D.C. showing assorted machinery and apparatus.

The Fixed Nitrogen Research Laboratory…

Photograph of James Wilson, Secretary of Agriculture from 1897 to 1913, seated in a horse-drawn carriage with an unidentified African American driver. Wilson's tenure as Secretary is regarded as a period distinguished…

General view of a glassblower, identified as L. Testa, working in an unidentified U.S. Department of Agriculture facility. Per a 1931 list of technical workers in the Department of Agriculture, Testa worked as a…