USA

The first practical demonstration of this tractor took place in a peat field on Roberts Island on November 24, 1904, and was patented and in production by December of 1907. The existing machine represents the earliest gasoline-powered track-type tractors that were to help revolutionize agriculture, logging, construction, road building, and transportation around the world. Its design and development is credited to Benjamin Holt (1849-1920), president of the Holt Manufacturing Company of Stockton.

Developed by the Hohokam, a prehistoric group of Native Americans, the canal system in the Salt River Valley serviced more than 100,000 acres of mostly arid desert country in what is now southern Arizona. The prehistoric Hohokam constructed one of the largest and most sophisticated irrigation networks ever created using pre-industrial technology. 

The Polymer Research Institute was established in 1946 by Herman F. Mark, a pioneer in the study of giant molecules. The Institute brought together a number of polymer researchers to create the first academic facility in the United States devoted to the study and teaching of polymer science. Scientists associated with it later went on to establish polymer programs at other universities and institutions, contributing significantly to the development and growth of what has become a vital branch of chemistry, engineering, and materials science.

Havemeyer Hall was built between 1896 and 1898 under the leadership of Charles Frederick Chandler. It provided research and teaching facilities for faculty and students specializing in industrial, inorganic, organic, physical, and biological chemistry. Pioneering research done here led to the discovery of deuterium, for which Harold Clayton Urey received the Nobel Prize in 1934. Six others who did research here subsequently received the Nobel Prize, including Irving Langmuir, the first industrial chemist to be so honored, in 1932.

The precise system of measurements provided today by the U.S. Coast and Geodetic Survey originated with an act of Congress under the administration of Thomas Jefferson in 1807 that funded work on "an accurate chart" of America's coastal waters. Intended to aid sea-going commerce, the first work on this project, carried out in 1816 and 1817, helped establish a complex grid of geodetic reference points on which much of our land- and sea-based navigation now depends. 

The Hanford B-Reactor was the first plutonium production reactor to be placed in operation. Its success made possible the subsequent development of atomic energy. The research work, engineering, and planning required to make the reactor operate is one of our most advanced achievements. Much of the reactor core, cooling system, shielding, and auxiliary systems were designed by mechanical engineers.