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Bell, Gertrude Margaret Lowthian

(Encyclopedia)Bell, Gertrude Margaret Lowthian lōˈᵺēən [key], 1868–1926, British traveler, author, and government official, one of the builders of the modern state of Iraq, grad. Oxford, 1887. From 1899 on ...

tempera

(Encyclopedia)tempera tĕmˈpərə [key], painting method in which finely ground pigment is mixed with a solidifying base such as albumen, fig sap, or thin glue. When used in mural painting it is also known as fres...

friction

(Encyclopedia)friction, resistance offered to the movement of one body past another body with which it is in contact. In certain situations friction is desired. Without friction the wheels of a locomotive could not...

diffusion

(Encyclopedia)diffusion, in chemistry, the spontaneous migration of substances from regions where their concentration is high to regions where their concentration is low. Diffusion is important in many life process...

continental drift

(Encyclopedia)CE5 Continental drift (arrows indicate the directions of motion of the landmasses) A. Proposed reconstruction of the supercontinent Pangaea indicating the major present landmasses B. Proposed recon...

parallax

(Encyclopedia)CE5 The trigonometric parallax of a star, expressed by the angle θ, is a measure of its apparent motion against the background of more distant stars as a result of the earth's motions in its orbit...

acetic acid

(Encyclopedia)acetic acid əsēˈtĭk [key], CH3CO2H, colorless liquid that has a characteristic pungent odor, boils at 118℃, and is miscible with water in all proportions; it is a weak organic carboxylic acid (s...

magnetic pole

(Encyclopedia)magnetic pole, the two roughly opposite ends of the planet where the earth's magnetic intensity is the greatest, as the north and south magnetic poles. For the magnetic north, it is the direction from...

horology

(Encyclopedia)horology hōrŏlˈəjē [key], science of measuring time and technology of constructing instruments for its measurement or recording. Early measurements of the passage of time were based on observatio...

Halley, Edmond

(Encyclopedia)Halley, Edmond hălˈē, hôˈlē [key], 1656–1742, English astronomer and mathematician. He is particularly noted as the first astronomer to predict the return of a comet and the first to point out...