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Sullivan, Louis Henry

(Encyclopedia)Sullivan, Louis Henry, 1856–1924, American architect, b. Boston, studied at the Massachusetts Institute of Technology and the École des Beaux-Arts, Paris. He is of great importance in the evolution...

Bell, Alexander Graham

(Encyclopedia)Bell, Alexander Graham, 1847–1922, American scientist, inventor of the telephone, b. Edinburgh, Scotland, educated at the Univ. of Edinburgh and University College, London; son of Alexander Melville...

Davidson, Donald Herbert

(Encyclopedia)Davidson, Donald Herbert, 1917–2003, American philosopher, b. Springfield, Mass., grad. Harvard (B.A., 1939; Ph.D., 1949). A student of W. V. Quine, Davidson emerged as one of the major figures in p...

Hamilton, Sir William Rowan

(Encyclopedia)Hamilton, Sir William Rowan, 1805–65, Irish mathematician and astronomer, b. Dublin. A child prodigy, he had mastered 13 languages by the age of 13 and was still an undergraduate when he became prof...

Nicol prism

(Encyclopedia)Nicol prism nĭkˈəl [key], optical device invented (1828) by William Nicol of Edinburgh. It consists essentially of a crystal of calcite, or Iceland spar, that is cut at an angle into two equal piec...

rectifier

(Encyclopedia)rectifier, component of an electric circuit used to change alternating current to direct current. Rectifiers are made in various forms, all operating on the principle that current passes through them ...

Summerhill

(Encyclopedia)Summerhill, radical progressive school in Leiston, Suffolk, England, and the educational movement based on principles developed at the school. The school was founded (1924) by A. S. Neill, who headed ...

surface chemistry

(Encyclopedia)surface chemistry, study of chemical reactions in which the reactants are first adsorbed onto a surface medium (see adsorption) that then acts as a catalyst for the reaction; after the reaction the pr...

threshing

(Encyclopedia)threshing or thrashing, separation of grain from the stalk on which it grows and from the chaff or pod that covers it. The first known method was by striking the reaped ears of grain with a flail. In ...

spectroscope

(Encyclopedia)spectroscope, optical instrument for producing spectral lines and measuring their wavelengths and intensities, used in spectral analysis (see spectrum). When a material is heated to incandescence it e...