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Bürgi, Joost

(Encyclopedia)Bürgi, Joost or Jost, 1552–1632, Swiss mathematician and instrument maker. As the official clockmaker (1579–92) to Duke Wilhelm IV of Hesse-Kassell, he developed the first clock with a minute han...

microscope

(Encyclopedia)CE5 Compound microscope microscope, optical instrument used to increase the apparent size of an object. The electron microscope, which is not limited by the powers of optical lenses and light,...

astrolabe

(Encyclopedia)astrolabe ăsˈtrəlāb [key], instrument probably used originally for measuring the altitudes of heavenly bodies and for determining their positions and movements. Although its origin is ancient and ...

Hogwood, Christopher Jarvis Haley

(Encyclopedia)Hogwood, Christopher Jarvis Haley, 1941–2014, British conductor, musicologist, and harpsichordist, b. Nottingham, grad. Cambridge (1964). He was an leader of the early-music movement, which sought t...

Frederick William I

(Encyclopedia)Frederick William I, 1688–1740, king of Prussia (1713–40), son and successor of Frederick I. He continued the administrative reforms and the process of centralization begun by Frederick William, t...

clavichord

(Encyclopedia)CE5 Clavichord clavichord klăvˈĭkôrd [key], keyboard musical instrument invented in the Middle Ages. It consists of a small rectangular wooden box, placed upon a table or on legs, containing a...

Piazzolla, Ástor Pantaleón

(Encyclopedia)Piazzolla, Ástor Pantaleón, 1921–92, Argentinian composer and player of the bandoneón (a large accordionlike instrument), b. Mar del Plata. He spent much of his childhood in New York, returned (1...

ultimatum

(Encyclopedia)ultimatum ŭlˌtĭmāˈtəm [key], in international law, final, definitive terms submitted by one disputant nation to the other for immediate acceptance or rejection. Since refusal to accept the terms...

tone

(Encyclopedia)tone. In music, a tone is distinguished from noise by its definite pitch, caused by the regularity of the vibrations which produce it. Any tone possesses the attributes of pitch, intensity, and qualit...

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...