Astronomical Clock (Souvenir)

Prague (pron.: /ˈprɑːɡ/; Czech: Praha pronounced [ˈpraɦa] ( listen)) is the capital and largest city of the Czech Republic. It is the fourteenth-largest city in the European Union. It is also the historical capital of Bohemia proper. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its larger urban zone is estimated to have a population of nearly 2 million. The city has a temperate oceanic climate, with warm summers and chilly winters.

An astronomical clock is a clock with special mechanisms and dials to display astronomical information, such as the relative positions of the sun, moon, zodiacal constellations, and sometimes major planets.

Old Town (Czech: Staré Město) is a medieval settlement of Prague, Czech Republic. It was separated from the outside by a semi-circular moat and wall, connected to the Vltava at both of its ends. The moat is now covered up by the streets (from north to south-west) Revolučni, Na Příkopě, and Národni—which remain the official boundary of the cadastral district of Old Town. It is now in Praha 1.

Soon after the city was expanded in the 14th century by Charles IV with the founding of the New Town, the moat and wall were dismantled.

Notable places in the Old Town include the Old New Synagogue, Old Town Square and Astronomical Clock. Across the river Vltava is the Lesser Quarter, called Malá Strana in Czech. These two parts of the town are connected by Charles Bridge. Josefov is located in the northwest corner of Old Town heading towards the Vltava.

From its early existence, around 9th century, Staré Město was laid out of settlements which appeared from the spacious marketplace on the bank of Vltava. Records dating back to 1100AD indicate that every Saturday a market was held on the marketplace, and large military gatherings also took place there. Thanks to the trade the nearby area merchants became rich, and when the King Václav I gave them the privileges of township, the town of Město Pražské (the town of Prague) was formed. According to ancient records, the city had around 13 gates, and a huge moat, providing strong defenses.

A clock is an instrument used to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning "bell". A silent instrument missing such a mechanism has traditionally been known as a timepiece. In general usage today a "clock" refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one's person are often distinguished from clocks.

The clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day; the lunar month; and the year. Devices operating on several different physical processes have been used over the millennia, culminating in the clocks of today.

The study of timekeeping is known as horology.

A clock face or dial is the part of an analog clock (or watch) that displays the time through the use of a fixed-numbered dial or dials and moving hands. In its most basic form, recognized throughout the world, the periphery of the dial is numbered 1 through 12 indicating the hours in a 12-hour cycle, and a short hour hand makes two revolutions in a day. A longer minute hand makes one revolution every hour. The face may also include a seconds hand which makes one revolution per minute. The term is less commonly used for the time display on digital clocks and watches.

A second type of clock face is the 24-hour analog dial, widely used in military and other organizations that use 24-hour time. This is similar to the 12-hour dial above, except it has hours numbered 1–24 around the outside, and the hour hand makes only one revolution per day. Some special-purpose clocks, such as timers and sporting event clocks, are designed for measuring periods less than one hour. Clocks can indicate the hour with Roman numerals or Hindu–Arabic numerals, or with non-numeric indicator marks. The two numbering systems have also been used in combination, with the prior indicating the hour and the later the minute. Longcase clocks (also known as grandfather clocks) typically use Roman numerals for the hours. Clocks using only Arabic numerals first began to appear in the mid-18th century. The periphery of a clock's face, where the numbers and other graduations appear, is often called the chapter ring.