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prostaglandin

(Encyclopedia)prostaglandin prŏsˌtəglănˈdən [key], any of a group of about a dozen compounds synthesized from fatty acids in mammals as well as in lower animals. Prostaglandins are highly potent substances th...

pseudocoelomate

(Encyclopedia)pseudocoelomate so͞oˌdōsēˈləmātˌ [key], any of a group of invertebrates with a three-layered body that has a fluid-filled body cavity (pseudocoelom) between the endoderm and the mesoderm (the ...

Homestead Act

(Encyclopedia)Homestead Act, 1862, passed by the U.S. Congress. It provided for the transfer of 160 acres (65 hectares) of unoccupied public land to each homesteader on payment of a nominal fee after five years of ...

Indian Territory

(Encyclopedia)Indian Territory, in U.S. history, name applied to the country set aside for Native Americans by the Indian Intercourse Act (1834). In the 1820s, the federal government began moving the Five Civilized...

Jugurtha

(Encyclopedia)Jugurtha jo͞ogûrˈthə [key], c.156–104 b.c., king of Numidia, a grandson of Masinissa. On the death of Micipsa (118 b.c.), the royal power devolved upon his two sons and upon his adopted son Jugu...

surface tension

(Encyclopedia)surface tension, tendency of liquids to reduce their exposed surface to the smallest possible area. A drop of water, for example, tends to assume the shape of a sphere. The phenomenon is attributed to...

Tannenberg

(Encyclopedia)Tannenberg täˈnənbĕrkˌ [key], Pol. Stębark, village, Warmińsko-Mazurskie prov., NE Poland, near Olsztyn. Formerly in East Prussia, it was transferred (1945) by the Potsdam Conference to Polish ...

skywriting

(Encyclopedia)skywriting, advertising medium in which aircraft spell out trade names and sales slogans in the sky by means of the controlled emission of thick smoke. The technique was first developed (1922) by J. C...

spring, in mechanics

(Encyclopedia)spring, in mechanics, any of several elastic devices used variously to store and to furnish energy, to absorb shock, to sustain the pressure between contacting surfaces, and to resist tensional or com...

weather

(Encyclopedia)weather, state of the atmosphere at a given time and place with regard to temperature, air pressure (see barometer), wind, humidity, cloudiness, and precipitation. The term weather is restricted to co...