SPECIATION.
Evripos Strait See Euripus Strait
Ewald Va-vohA, Johannes (b. Nov. 18, 1743, Copenhagen, Den.—d. March 17, 1781, Copenhagen) Danish poet and dramatist. By age 19 he was becoming known as a writer. At 30, addicted to alcohol, he adopted a more solitary life and began producing his mature works, including The Death of Balder (1774), in which he became the first Danish poet to use themes from Scandinavian myth and saga. Of his dramatic works, only the operetta Fiskerne (1779; “The Fishermen”) is still performed. He is espe¬ cially known for his great personal odes and for songs such as “King Christian Stood by the Lofty Mast,” used as a national anthem, and “Lille Gunver,” the first Danish romance. He is considered one of Denmark’s greatest lyric poets. His memoirs (published 1804) are his greatest prose work.
Ewe \'a-wa\ Peoples of southeastern Ghana, southern Benin, and south¬ ern Togo. They speak dialects of Gbe, a Kwa language of the Niger-Congo family. The Ewe never formed a single centralized state, remaining a col¬ lection of independent communities that made temporary alliances in time of war. Most Ewe are farmers; some coastal Ewe fish. Spinning, weav¬ ing, pottery making, and blacksmithing are important crafts. They num¬ ber more than 3.5 million.
Ewing Vyii-iqV (William) Maurice (b. May 12, 1906, Lockney, Texas, U.S.—d. May 4, 1974, Galveston, Texas) U.S. geophysicist. He taught many years at Columbia University (1944-74) and also directed the Lamont-Doherty Geological Observatory (1949-74). Studying the structure of the Earth’s crust and mantle, he made seismic refraction mea¬ surements in the Atlantic basins, along the Mid-Atlantic Ridge, and in the Mediterranean and Norwegian seas. In 1935 he took the first seismic measurements in open seas. He was among those who proposed that earthquakes are associated with the central oceanic rifts that encircle the globe, suggesting that seafloor spreading may be worldwide and episodic in nature. In 1939 he took the first deep-sea photographs.
excavation In archaeology, the exposure, recording, and recovery of buried material remains. The techniques employed vary by the type of site, but all forms of archaeological excavation require great skill and careful preparation. The process begins with site location, by means of aerial photography, remote sensing, or, commonly, accidental discovery by construction crews. This step is followed by surveying and mapping, site sampling, and developing an excavation plan. The design and execu¬ tion of an excavation frequently require an interdisciplinary team of experts. The actual digging consists of the removal of surplus dirt and the painstaking examination, through observation, sifting, and other means, of remaining soil, artifacts, and context. Common dig tools include the trowel, penknife, and brush. The excavation phase is followed by artifact classification, analysis, dating, and the publication of results. Excavation may last decades or be a short-term emergency salvage operation (as when a site is threatened by development).
exchange, bill of See bill of exchange
exchange control Governmental restrictions on private transactions in foreign money or claims on foreign money. Residents are required to
sell foreign money coming into their possession to a central bank or spe¬ cialized government agency at exchange rates set by the government. The chief function of most systems of exchange control is to maintain a favour¬ able BALANCE OF PAYMENTS. See also FOREIGN EXCHANGE.
exchange rate Price of one country’s money in relation to another’s. Exchange rates may be fixed or flexible. An exchange rate is fixed when two countries agree to maintain a fixed rate through the use of monetary policy. Historically, the most famous fixed exchange-rate system was the gold standard; in the late 1850s, one ounce of gold was defined as being worth 20 U.S dollars and 4 pounds sterling, resulting in an exchange rate of 5 dollars per pound. An exchange rate is flexible, or “floating,” when two countries agree to let international market forces determine the rate through supply and demand. The rate will fluctuate with a country’s exports and imports. Most world trade currently takes place with flexible exchange rates that fluctuate within relatively fixed limits. See also EXCHANGE CONTROL, FOREIGN EXCHANGE.
Exchequer \iks-'che-kar, 'eks-.che-korV English government department responsible for receiving and dispersing public revenue. It was established by Henry I in the 12th century, and its name refers to the checkered cloth on which the reckoning of revenues took place. Originally, the lower Exchequer was an office for the receipt and payment of money, while the upper Exchequer was a court sitting twice a year to regulate accounts. The English judicial system grew out of the upper Exchequer, and the lower Exchequer became the Treasury. “Exchequer” is still the unofficial name of the Treasury in Britain.
excitation Addition of a discrete amount of energy to a system that changes it usually from a state of lowest energy (ground state) to one of higher energy (excited state). For example, in a hydrogen atom, an exci¬ tation energy of 10.2 electron volts is required to move the lone electron from its ground state to its first excited state. The excitation energy stored in excited atoms and nuclei is usually emitted as ultraviolet radiation from atoms and as gamma radiation (see gamma ray) from nuclei as they return to their ground states.
exclusionary rule In U.S. law, the principle that evidence seized by police in violation of the constitutional protection against unreasonable search and seizure may not be used against a criminal defendant at trial. The Supreme Court of the United States established the validity of the rule in Weeks v. U.S. (1914). In Wolf v. Colorado (1949) the court limited application of the rule to the federal courts; this decision was overturned in Mapp v. Ohio (1961), which required the rule to be applied universally. In the 1980s the court allowed an exception to the rule, holding that evi¬ dence obtained “in good faith” with a search warrant later ruled invalid is admissible.
excommunication Form of censure by which a member of a religious body is excluded from the congregation of believers and from the rites of the church. Excommunication has been used in various religions, nota¬ bly Christianity, as a punishment for grave offenses such as heresy. In Roman Catholicism an excommunicated person is barred from receiving the sacraments and from burial in consecrated ground. The offender may be absolved by a priest (in some cases, only by a bishop or the pope) and received back into the church after confessing his or her sin and doing penance for it. In Protestant denominations other terms, such as “church discipline,” may be attached to essentially the same censure. Although now seldom used, the practice of herein in Judaism was a form of excom¬ munication that excluded people from the community for prescribed times or forbade them from hearing the Torah. The term is also applied to the expulsion of Buddhist monks from the sangha.