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Morse code

(Encyclopedia)CE5 Morse code [for S. F. B. Morse], the arbitrary set of signals used on the telegraph (see code). It may also be used with a flash lamp for visible signaling. The international (or continental) M...

chart

(Encyclopedia)chart, term referring to maps prepared for marine navigation and for air navigation. All charts show, in some convenient scale, geographic features useful to the navigator, as well as indications of d...

amplifier

(Encyclopedia)amplifier, device that accepts a varying input signal and produces an output signal that varies in the same way as the input but has a larger amplitude. The input signal may be a current, a voltage, a...

atlas, in geography

(Encyclopedia)atlas, in geography, collection of maps or charts. It usually includes data on various features of a country, e.g., its topography, natural resources, climate, and population, as well as its agricultu...

Banneker, Benjamin

(Encyclopedia)Banneker, Benjamin, 1731–1806, African-American inventor, astronomer, and mathematician, b. Baltimore co., Md., at what is now Ellicott's Mills. A free black, Banneker was essentially self-taught. H...

color index

(Encyclopedia)color index, in astronomy, difference in an object's brightness as recorded between any two well-defined bands of the electromagnetic spectrum by using optical filters of different colors. If blue and...

Al-Biruni, Abu Rayhan Muhammad ibn Ahmad

(Encyclopedia)Al-Biruni or Al Beruni, Abu Rayhan Muhammad ibn Ahmad äbo͞oˈ rīhänˈ məhămˈĭd ĭbˈən äˈməd ăl-bēro͞oˈnē, ăl bĕro͞oˈnē [key], b. 973, d. after 1050, Central Asian scientist. His...

Chaldaea

(Encyclopedia)Chaldaea or Chaldea both: kăldēˈə [key], properly the southernmost portion of the valley of the Tigris and the Euphrates rivers. Sometimes it is extended to include Babylonia and thus comprises al...

Behaim, Martin

(Encyclopedia)Behaim, Behem, or Boeheim, Martin all: bāˈhīm [key], b. 1436? or 1459?, d. 1506?, German traveler and cosmographer. He studied (possibly under Regiomontanus) astronomy, navigation, and mathematics....

Bailly, Jean Sylvain

(Encyclopedia)Bailly, Jean Sylvain zhäN sēlvăNˈ bäyēˈ [key], 1736–93, French astronomer and politician. His works on astronomy and on the history of science (notably the Essai sur la théorie des satellite...