Columbia Encyclopedia

(Encyclopedia) railroad or railway, form of transportation most commonly consisting of steel rails, called tracks, on which trains of freight cars, passenger cars, and other rolling stock are drawn by one locomotive...

(Encyclopedia) physics, branch of science traditionally defined as the study of matter, energy, and the relation between them; it was called natural philosophy until the late 19th cent. and is still known by this na...

(Encyclopedia) mathematics, deductive study of numbers, geometry, and various abstract constructs, or structures; the latter often “abstract” the features common to several models derived from the empirical, or ...

(Encyclopedia)  CE5 Roman Empire (a.d. 117) CE5 Rome, Ital. Roma, city (1991 pop. 2,775,250), capital of Italy and see of the pope, whose residence, Vatican City, is a sovereign state within the city of Rome. R...

(Encyclopedia)  Text1 of the Constitution of the United States Preamble Article I Article II Article III Article IV Article V Article VI Article VII Amendment I Amendment II Am...

(Encyclopedia)  CE5 CE5 Egypt ēˈjĭpt [key], Arab. Misr, biblical Mizraim, officially Arab Republic o...

(Encyclopedia)  National Parks and Monuments 1 National Parks and Monuments National Monuments National and International Historic Sites and Historical Parks National Memorials National Battlef...

(Encyclopedia)  CE5 CE5 CE5 United States, officially United States of America, republic (2015 est. pop. 319,929,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third l...