Category Geography

Do you know how precious stones are cut?

The cutting and polishing of diamonds are very delicate many varieties of glass beads.

Today we know that Zimbabwe was inhabited around 1000 B.C. and was only one of about 2000 such centres scattered through the country called Zimbabwe.

All gems are cut and polished by progressive abrasion using finer and finer grits of harder substances. Diamond, the hardest naturally occurring substance, has a Mohs hardness of 10 and is used as an abrasive to cut and polish a wide variety of materials, including diamond itself. Silicon carbide, a manmade compound of silicon and carbon with a Mohs hardness of 9.5, is also widely used for cutting softer gemstones. Other compounds, such as cerium oxide, tin oxide, chromium oxide, and aluminum oxide, are frequently used in polishing gemstones.

 

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How the salt removed from sea-water?

For years engineers and scientists have tried to solve the massive problem of removing salt from sea-water to meet the growing demand for fresh water. Several land-based stills have been built in arid regions such as Kuwait, where local oil deposits supply the fuel, but production costs are high.

Scientists have been able to desalinate sea-water by using nuclear power. Basically what happens is that the water is heated until it evaporates. The vapour is the condensed through cooling and distilled to produce fresh water. The only problem is to have a source of considerable heat which is cheap to use. Such heat could come from nuclear reactors.

 

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What is the exact way to draw a map?

The ancient people had a very inaccurate idea of the size and shape of the Earth. They represented it in strange ways, imagining it was shaped like a flat disc surrounded by mysterious seas and oceans.

At one time it took a great deal of patient, detailed work to draw the map of a region. Today, cartography, as the art of map drawing is called, is done very rapidly and with great accuracy.

Maps are now drawn by computers which can read photographs of regions taken from the air. A greater number of maps are now produced than ever before, giving more diverse and accurate information.

 

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When beet-sugar was first produced?

The sugar-beet was known as a garden vegetable and for cattle fodder before it was valued for its sugar. As early as the 1500s, however, we come across the first accounts of the sweet juice obtained from boiling these plants.

It was not until the 1700s that the sugar-beet industry made its first simple beginnings. The idea came from a German scientist called Marggraf.

In 1747 he obtained 50 grammas of pure sugar by treating 200 grammas of dried root of beet with crude ethyl alcohol. Other scientists took up the experiments. Governments donated land and money for further research to be carried out and the first sugar-beet factory was built in Silesia in 1803.

Eventually, by the 1850s, beet sugar was able to complete with cane sugar. Today about a quarter of the world’s sugar is produced from sugar-beet.

 

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Located on Port Jackson in Australia, which building, with white sail-shaped shells as its roof structure, is one of the most-photographed buildings in the world?

Sydney Opera House, opera house located on Port Jackson (Sydney Harbour), New South Wales, Australia. Its unique use of a series of gleaming white sail-shaped shells as its roof structure makes it one of the most-photographed buildings in the world.

The building and its surrounds occupy the whole of Bennelong Point on Sydney Harbour, between Sydney Cove and Farm Cove, adjacent to the Sydney central business district and the Royal Botanic Gardens, and close by the Sydney Harbour Bridge.

The building comprises multiple performance venues, which together host well over 1,500 performances annually, attended by more than 1.2 million people. Performances are presented by numerous performing artists, including three resident companies: Opera Australia, the Sydney Theatre Company and the Sydney Symphony Orchestra. As one of the most popular visitor attractions in Australia, the site is visited by more than eight million people annually, and approximately 350,000 visitors take a guided tour of the building each year. The building is managed by the Sydney Opera House Trust, an agency of the New South Wales State Government.

On 28 June 2007, the Sydney Opera House became a UNESCO World Heritage Site, having been listed on the (now defunct) Register of the National Estate since 1980, the National Trust of Australia register since 1983, the City of Sydney Heritage Inventory since 2000, the New South Wales State Heritage Register since 2003, and the Australian National Heritage List since 2005. Furthermore, the Opera House was a finalist in the New7Wonders of the World campaign list.

 

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Where is the Acropolis of Athens located?

The Acropolis of Athens is an ancient citadel located on a rocky outcrop above the city of Athens and contains the remains of several ancient buildings of great architectural and historic significance, the most famous being the Parthenon. The word acropolis is from the Greek words ????? (akron, “highest point, extremity”) and ????? (polis, “city”).Although the term acropolis is generic and there are many other acropoleis in Greece, the significance of the Acropolis of Athens is such that it is commonly known as “The Acropolis” without qualification. During ancient times it was known also more properly as Cecropia, after the legendary serpent-man, Cecrops, the supposed first Athenian king.

The word acropolis literally means in Greek “upper city,” and though associated primarily with the Greek cities Athens, Argos (with Larissa), Thebes (with Cadmea), and Corinth (with its Acrocorinth), may be applied generically to all such citadels, including Rome, Carthage, Jerusalem, Celtic Bratislava, many in Asia Minor, or even Castle Rock in Edinburgh. An example in Ireland is the Rock of Cashel. Acropolis is also the term used by archaeologists and historians for the urban Castro culture settlements located in Northwestern Iberian hilltops.

The most famous example is the Acropolis of Athens, which, by reason of its historical associations and the several famous buildings erected upon it (most notably the Parthenon), is known without qualification as the Acropolis. The Acropolis of Athens achieved its form in the fifth century BC and is currently an archeological site. Although originating in the mainland of Greece, use of the acropolis model quickly spread to Greek colonies such as the Dorian Lato on Crete during the Archaic Period.

 

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