City

A city is a large and permanent human settlement. Although there is no agreement on how a city is distinguished from a town in general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.

Cities generally have complex systems for sanitation, utilities, land usage, housing, and transportation. The concentration of development greatly facilitates interaction between people and businesses, benefiting both parties in the process, but it also presents challenges to managing urban growth.

A big city or metropolis usually has associated suburbs and exurbs. Such cities are usually associated with metropolitan areas and urban areas, creating numerous business commuters traveling to urban centers for employment. Once a city expands far enough to reach another city, this region can be deemed a conurbation or megalopolis. In terms of population, the largest city proper is Shanghai, while the fastest-growing is Dubai.

Origins

There is not enough evidence to assert what conditions gave rise to the first cities. Some theorists have speculated on what they consider suitable pre-conditions and basic mechanisms that might have been important driving forces.

City government in Washington (state)

There are 281 municipalities in the U.S. state of Washington. State law determines the various powers its municipalities have.

City classes

Legally, a city in Washington can be described primarily by its class. There are five classes of cities in Washington:

First class cities are cities with a population over 10,000 at the time of reorganization and operating under a home rule charter. They are permitted to perform any function specifically granted them by Title 35 RCW (Revised Code of Washington). Among them are Seattle, Tacoma, Spokane, Vancouver, and Yakima.

Second class cities are cities with a population over 1,500 at the time of reorganization and operating without a home rule charter. Like first class cities, they are permitted to perform any function specifically granted them by Title 35 RCW. Among them are Port Orchard, Wapato, and Colville.

Towns are municipalities with a population of under 1,500 at the time of reorganization. Towns are not authorized to operate under a charter. Like the previously listed cities, they are permitted to perform any function specifically granted them by Title 35 RCW. Among them are Steilacoom, Friday Harbor, Eatonville, and Waterville. In 1994, the legislature made 1,500 the minimum population required to incorporate.

Administrative divisions of Texas

Texas has a total of 254 counties, many cities, and numerous special districts, the most common of which is the independent school district.

County

Texas has a total of 254 counties, by far the largest number of counties of any state.

Each county is run by a five-member Commissioners' Court consisting of four commissioners elected from single-member districts (called commissioner precincts) and a county judge elected at-large. The county judge does not have authority to veto a decision of the commissioners court; the judge votes along with the commissioners (being the tie-breaker in close calls). In smaller counties, the county judge actually does perform judicial duties, but in larger counties the judge's role is limited to serving on the commissioners court and certifying elections. Certain officials, such as the sheriff and tax collector, are elected separately by the voters, but the commissioners court determines their office budgets, and sets overall county policy. All county elections are partisan, and commissioner precincts are redistricted after each ten year Census both to equalize the voting power in each and in consideration of the political party preferences of the voters in each.

Eratosthenes

Eratosthenes of Cyrene (/ɛrəˈtɒsθəniːz/; Greek: Ἐρατοσθένης, IPA: [eratostʰénɛːs]; c. 276 BC – c. 195/194 BC) was a Greek mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. He invented the discipline of geography, including the terminology used today.

He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, which was a standard unit of measure during that time period. His calculation was remarkably accurate. He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day. He created the first map of the world incorporating parallels and meridians, based on the available geographical knowledge of the era.

Eratosthenes was the founder of scientific chronology; he endeavored to revise the dates of the chief literary and political events from the conquest of Troy. In number theory, he introduced the sieve of Eratosthenes, an efficient method of identifying prime numbers.