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sand

(Encyclopedia)sand, rock material occurring in the form of loose, rounded or angular grains, varying in size from .06 mm to 2 mm in diameter, the particles being smaller than those of gravel and larger than those o...

Mendeleev, Dmitri Ivanovich

(Encyclopedia)Mendeleev, Dmitri Ivanovich mĕndəlāˈəf, Rus. dəmēˈtrē ēväˈnəvĭch myĭndyĭlyāˈəf [key], 1834–1907, Russian chemist. He is famous for his formulation (1869) of the periodic law and t...

Marbut, Curtis Fletcher

(Encyclopedia)Marbut, Curtis Fletcher märˈbət [key], 1863–1935, American geologist, b. Verona, Mo., grad. Univ. of Missouri (B.S., 1889) and Harvard (M.A., 1844). As professor of geology at the Univ. of Missou...

Cutter, Charles Ammi

(Encyclopedia)Cutter, Charles Ammi, 1837–1903, American librarian, b. Boston. Cutter cataloged the library of the Harvard Divinity School and in 1860 was appointed as the assistant to the librarian of Harvard. As...

Kraepelin, Emil

(Encyclopedia)Kraepelin, Emil krĕpəlēnˈ [key], 1856–1926, German psychiatrist, educated at Würzburg (M.D., 1878). He also studied under Wilhelm Wundt in Leipzig, and was appointed professor of psychiatry at ...

rammed earth

(Encyclopedia)rammed earth, material consisting chiefly of soil of sufficiently stiff consistency that has been placed in forms and pounded down. It has been used for buildings and walls since ancient times and was...

Bessemer process

(Encyclopedia)CE5 Bessemer converter Bessemer process bĕsˈəmər [key] [for Sir Henry Bessemer], industrial process for the manufacture of steel from molten pig iron. The principle involved is that of oxidati...

soil

(Encyclopedia)soil, surface layer of the earth, composed of fine rock material disintegrated by geological processes; and humus, the organic remains of decomposed vegetation. In agriculture, soil is the medium that...

loam

(Encyclopedia)loam, soil composed of sand, silt, clay, and organic matter in evenly mixed particles of various sizes. More fertile than sandy soils, loam is not stiff and tenacious like clay soils. Its porosity all...

cement

(Encyclopedia)cement, binding material used in construction and engineering, often called hydraulic cement, typically made by heating a mixture of limestone and clay until it almost fuses and then grinding it to a ...