Iowa Heritage Digital Collections
State Library of Iowa

Browse Items (170 total)

Professor David R. Boylan working with shaft furnace

Professor David R. Boylan working with shaft furnace

Dr. Boylan is working with the shaft furnace in the preparation of fused potassium magnesium phosphate for fertilizer.
Professor David R. Boylan working with shaft furnace

Professor David R. Boylan working with shaft furnace

Dr. Boylan is working with the shaft furnace in the preparation of fused potassium magnesium phosphate for fertilizer.
Processing plant, 1938

Processing plant, 1938

At the center of this view from the balcony level is a large chained pulley. Several long pipes with spigots run horizontally above the wooden floor.
Processing plant, 1938

Processing plant, 1938

At the center of this view from the balcony level is a large chained pulley. Several long pipes with spigots run horizontally above the wooden floor.
Pouring milkweed seeds into the solvent oil extractor, Oil extraction plant

Pouring milkweed seeds into the solvent oil extractor, Oil extraction plant

A researcher is pouring milkweed seeds into the solvent oil extractor in making milkweed oil. Professor Orland Sweeney is observing the process from below.
Pouring milkweed seeds into the solvent oil extractor, Oil extraction plant

Pouring milkweed seeds into the solvent oil extractor, Oil extraction plant

A researcher is pouring milkweed seeds into the solvent oil extractor in making milkweed oil. Professor Orland Sweeney is observing the process from below.
Piece of equipment, close-up view, 1937

Piece of equipment, close-up view, 1937

This is a close-up view of one section of a piece of equipment. See photograph 840-02-04 for a larger view.
Piece of equipment, close-up view, 1937

Piece of equipment, close-up view, 1937

This is a close-up view of one section of a piece of equipment. See photograph 840-02-04 for a larger view.
Piece of equipment and press, 1939

Piece of equipment and press, 1939

The two pieces of equipment on the left measure milliamperes and microamperes and are connected to another piece of equipment on the right.
Piece of equipment and press, 1939

Piece of equipment and press, 1939

The two pieces of equipment on the left measure milliamperes and microamperes and are connected to another piece of equipment on the right.
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