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Izaak Maurits Kolthoff (1894–1993) has been described as the father of modern analytical chemistry for his research and teaching that transformed the ways by which scientists separate, identify, and quantify chemical substances. Once a collection of empirical recipes and prescriptions, the field of analytical chemistry is today an essential branch of chemistry built upon solid theoretical principles and experimental techniques, the basis of which was formed over the course of Kolthoff’s nearly 80-year career.

The oldest surviving rotary snowplow in the world

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Designed by William A. Truesdell, a railroad engineer, the Seventh Street Improvement Arches celebrates the engineering application of mathematics to improve living conditions.

No image dominates the Midwestern landscape like the monolithic grain elevator, whose present shape and construction owe much to grain company operator Frank Peavy and architect-builder Charles Haglin.

Wanting to improve on the flammability and cost of traditional wood-cribbed construction, Peavy speculated that reinforced concrete, in its infancy at the turn of the century, would outperform other materials. But critics feared that the elevator would collapse due to the vacuum created when grain was emptied from the air-tight structure.

The refrigeration units placed on trucks in 1938 by Thermo King Corp. revolutionized the transportation of perishable foods. Today they are a common sight on streets everywhere. Consumer demand for meat, poultry, produce and dairy products increased at an astounding rate. These installations and subsequent ones on refrigerated vehicles, ships, and railroads have had worldwide impact on the preservation of food and other perishables during distribution.