document_title: Gypsum

question_text: where does gypsum often form (site 3)

question_tokens: where does gypsum often form ( site 3 )

text: Gypsum

text: Etymology and history[edit]

text: The word gypsum is derived from the Greek word γύψος (gypsos), "plaster".[4] Because the quarries of the Montmartre district of Paris have long furnished burnt gypsum (calcined gypsum) used for various purposes, this dehydrated gypsum became known as plaster of Paris. Upon addition of water, after a few tens of minutes plaster of Paris becomes regular gypsum (dihydrate) again, causing the material to harden or "set" in ways that are useful for casting and construction.

text: Gypsum was known in Old English as spærstān, "spear stone", referring to its crystalline projections. (Thus, the word spar in mineralogy is by way of comparison to gypsum, referring to any non-ore mineral or crystal that forms in spearlike projections).  In the mid-18th century, the German clergyman and agriculturalist Johann Friderich Mayer investigated and publicized gypsum's use as a fertilizer.[5]  Gypsum may act as a source of sulfur for plant growth, and in the early 19th century, it was regarded as an almost miraculous fertilizer. American farmers were so anxious to acquire it that a lively smuggling trade with Nova Scotia evolved, resulting in the so-called "Plaster War" of 1820.[6] In the 19th century, it was also known as lime sulfate or sulfate of lime.

text: Physical properties[edit]

text: Gypsum is moderately water-soluble (~2.0–2.5 g/l at 25 °C)[7] and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures. When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, (bassanite, often simply called "plaster") and, if heated further, to anhydrous calcium sulfate (anhydrite).  As for anhydrite, its solubility in saline solutions and in brines is also strongly dependent on NaCl (common table salt) concentration.[7]

text: Gypsum crystals are found to contain anion water and hydrogen bonding.[8]

text: Crystal varieties[edit]

text: Gypsum occurs in nature as flattened and often twinned crystals, and transparent, cleavable masses called selenite. Selenite contains no significant selenium; rather, both substances were named for the ancient Greek word for the Moon.

text: Selenite may also occur in a silky, fibrous form, in which case it is commonly called "satin spar". Finally, it may also be granular or quite compact. In hand-sized samples, it can be anywhere from transparent to opaque. A very fine-grained white or lightly tinted variety of gypsum, called alabaster, is prized for ornamental work of various sorts. In arid areas, gypsum can occur in a flower-like form, typically opaque, with embedded sand grains called desert rose. It also forms some of the largest crystals found in nature, up to 12 m (39 ft) long, in the form of selenite.[9]

text: Occurrence[edit]

text: Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon.[10] Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface exposures. It is often associated with the minerals halite and sulfur. Gypsum is the most common sulfate mineral.[11] Pure gypsum is white, but other substances found as impurities may give a wide range of colors to local deposits.

text:
Because gypsum dissolves over time in water, gypsum is rarely found in the form of sand.  However, the unique conditions of the White Sands National Monument in the US state of New Mexico have created a 710 km2 (270 sq mi) expanse of white gypsum sand, enough to supply the construction industry with drywall for 1,000 years.[12]
Commercial exploitation of the area, strongly opposed by area residents, was permanently prevented in 1933 when president Herbert Hoover declared the gypsum dunes a protected national monument.

text: Gypsum is also formed as a by-product of sulfide oxidation, amongst others by pyrite oxidation, when the sulfuric acid generated reacts with calcium carbonate. Its presence indicates oxidizing conditions. Under reducing conditions, the sulfates it contains can be reduced back to sulfide by sulfate-reducing bacteria. Electric power stations burning coal with flue gas desulfurization produce large quantities of gypsum as a byproduct from the scrubbers.

text: Orbital pictures from the Mars Reconnaissance Orbiter (MRO) have indicated the existence of gypsum dunes in the northern polar region of Mars,[13] which were later confirmed at ground level by the Mars Exploration Rover (MER) Opportunity.[14]

text:
Gypsum crystals in the Cave of the Crystals in Mexico. Note person for scale

Veins of gypsum in the silts/marls of the Tea Green and Grey Marls, Blue Anchor, Somerset, UK

Veins of gypsum in Caprock Canyons State Park, Texas

text: Mining[edit]

text:
Estimated production of Gypsum in 2015(thousand metric tons)[15]

Country
Production
Reserves

China
132,000
N/A

Iran
22,000
1,600

Thailand
12,500
N/A

United States
11,500
700,000

Turkey
10,000
N/A

Spain
6,400
N/A

Mexico
5,300
N/A

Japan
5,000
N/A

Russia
4,500
N/A

Italy
4,100
N/A

India
3,500
39,000

Australia
3,500
N/A

Oman
3,500
N/A

Brazil
3,300
290,000

France
3,300
N/A

Canada
2,700
450,000

Saudi Arabia
2,400
N/A

Algeria
2,200
N/A

Germany
1,800
450,000

Argentina
1,400
N/A

Pakistan
1,300
N/A

United Kingdom
1,200
55,000

Other countries
15,000
N/A

World total
258,000
N/A

text: Commercial quantities of gypsum are found in the cities of Araripina and Grajaú in Brazil; in Pakistan, Jamaica, Iran (world's second largest producer), Thailand, Spain (the main producer in Europe), Germany, Italy, England, Ireland, Canada[16] and the United States. Large open pit quarries are located in many places including Fort Dodge, Iowa, which sits on one of the largest deposits of gypsum in the world,[citation needed] and Plaster City, California, United States, and East Kutai, Kalimantan, Indonesia. Several small mines also exist in places such as Kalannie in Western Australia, where gypsum is sold to private buyers for additions of calcium and sulfur as well as reduction of aluminum toxicities on soil for agricultural purposes.

text: Crystals of gypsum up to 11 m (36 ft) long have been found in the caves of the Naica Mine of Chihuahua, Mexico. The crystals thrived in the cave's extremely rare and stable natural environment. Temperatures stayed at 58 °C (136 °F), and the cave was filled with mineral-rich water that drove the crystals' growth. The largest of those crystals weighs 55 tons and is around 500,000 years old.[17]

text:
Golden gypsum crystals from Winnipeg

Gypsum sand from White Sands National Monument, New Mexico

text: Synthesis[edit]

text: Synthetic gypsum is recovered via flue-gas desulfurization at some coal-fired power plants. It can be used interchangeably with natural gypsum in some applications.

text: Gypsum also precipitates onto brackish water membranes, a phenomenon known as mineral salt scaling, such as during brackish water desalination of water with high concentrations of calcium and sulfate. Scaling decreases membrane life and productivity. This is one of the main obstacles in brackish water membrane desalination processes, such as reverse osmosis or nanofiltration. Other forms of scaling, such as calcite scaling, depending on the water source, can also be important considerations in distillation, as well as in heat exchangers, where either the salt solubility or concentration can change rapidly.

text: A new study has suggested that the formation of gypsum starts as tiny crystals of a mineral called bassanite (CaSO4·0.5H2O).[18] This process occurs via a three-stage pathway:

text:
homogeneous nucleation of nanocrystalline bassanite;
self-assembly of bassanite into aggregates, and
transformation of bassanite into gypsum.

tag: ol

text: Occupational safety[edit]

text: People can be exposed to gypsum in the workplace by breathing it in, skin contact, and eye contact.

text: United States[edit]

text: The Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for gypsum exposure in the workplace as TWA 15 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of TWA 10 mg/m3 for total exposure and TWA 5 mg/m3 for respiratory exposure over an 8-hour workday.[19]

text: Uses[edit]

text: Gypsum is used in a wide variety of applications:

text:
Gypsum board[20] is primarily used as a finish for walls and ceilings, and is known in construction as drywall, wallboard, sheetrock or plasterboard.
Gypsum blocks are used like concrete blocks in building construction.
Gypsum mortar is an ancient mortar used in building construction.
Plaster ingredients are used in surgical splints, casting moulds and modeling.
Fertilizer and soil conditioner:  In the late 18th and early 19th centuries, Nova Scotia gypsum, often referred to as plaster, was a highly sought fertilizer for wheat fields in the United States. It is also used in ameliorating high-sodium soils,[21] such as in the Zuiderzee Works.[22]
A binder in fast-dry tennis court clay
As alabaster, a material for sculpture, it was used especially in the ancient world before steel was developed, when its relative softness made it much easier to carve.
A wood substitute in the ancient world: For example, when wood became scarce due to deforestation on Bronze Age Crete, gypsum was employed in building construction at locations where wood was previously used.[23]
A tofu (soy bean curd) coagulant, making it ultimately a major source of dietary calcium, especially in Asian cultures which traditionally use few dairy products
Adding hardness to water used for brewing[24]
Used in baking as a dough conditioner, reducing stickiness, and as a baked-goods source of dietary calcium.[25] The primary component of mineral yeast food.[26]
A component of Portland cement used to prevent flash setting of concrete
Soil/water potential monitoring (soil moisture)
A common ingredient in making mead
In the medieval period, scribes and illuminators mixed it with lead carbonate (powdered white lead) to make gesso, which was applied to illuminated letters and gilded with gold in illuminated manuscripts.
In foot creams, shampoos and many other hair products
A medicinal agent in traditional Chinese medicine called shi gao
Impression plasters in dentistry
Used in mushroom cultivation to stop grains from clumping together
Tests have shown that gypsum can be used to remove pollutants such as lead[27] or arsenic[28][29] from contaminated waters.

text: Gallery[edit]

text:
Unusual gypsum specimens from around the world

Green gypsum crystals from Pernatty Lagoon, Mt Gunson, South Australia - its green color is due to presence of copper ions.

Unusual selenite gypsum from the Red River, Winnipeg, Manitoba, Canada

Classic "ram's horn" gypsum from Santa Eulalia, Chihuahua, Mexico, 7.5×4.3×3.8 cm

Desert rose, 47 cm long

Gypsum from Pernatty Lagoon, Mt Gunson, Stuart Shelf area, Andamooka Ranges - Lake Torrens area, South Australia, Australia

Gypsum with crystalline native copper inside

Gypsum from Swan Hill, Victoria, Australia. The colouring is due to the copper oxide

Bright, cherry-red gypsum crystals 2.5 cm in height colored by rich inclusions of the rare mineral botryogen

Gypsum from Naica, Mun. de Saucillo, Chihuahua, Mexico

Golden color gem, "fishtail"-twinned crystals of Gypsum sitting atop a "ball" of Gypsum which is composed of several single bladed crystals


document_title: Exploration of Africa

question_text: who began exploration of africa's atlantic coast

question_tokens: who began exploration of africa 's atlantic coast

root

text: Exploration of Africa

text: Antiquity[edit]

text: The Phoenicians explored North Africa, establishing a number of colonies, the most prominent of which was Carthage. Carthage itself conducted exploration of West Africa. The first circumnavigation of the African continent was probably made by Phoenician sailors, in an expedition commissioned by Egyptian pharaoh Necho II, in c. 600 BC and took three years. A report of this expedition is provided by Herodotus (4.37). They sailed south, rounded the Cape heading west, made their way north to the Mediterranean and then returned home. He states that they paused each year to sow and harvest grain. Herodotus himself is sceptical of the historicity of this feat, which would have taken place close about 120 years before his birth; however, the reason he gives for disbelieving the story is the sailors' reported claim that when they sailed along the southern coast of Africa, they found the Sun stood to their right, in the north; Herodotus, who was unaware of the spherical shape of the Earth found this impossible to believe. Some commentators took this circumstance as proof that the voyage is historical, but other scholars still dismiss the report as unlikely. [1]

tag: p

text: The West African coast was explored by Hanno the Navigator in an expedition in c. 500 BC.[2] The report of this voyage survives in a short Periplus in Greek, which was first cited by Greek authors in the 3rd century BC.[3]:162–3 There is some uncertainty as to how far precisely Hanno reached, he clearly sailed as far as Sierra Leone, and may have continued as far as Guinea or even Gabon.[4]

text: Africa is named for the Afri people who settled in the area of current-day Tunisia. The Africa Province of the Roman Empire spanned the Mediterranean coast of what is now Libya, Tunisia and Algeria. The parts of North Africa north of the Sahara were well known in antiquity. Prior to the 2nd century BC, however, Greek geographers were unaware that the land mass then known as Libya expanded south of the Sahara, assuming that the desert bounded on the outer Ocean. Indeed, Alexander the Great, according to Plutarchus' Lives, considered sailing from the mouths of the Indus back to Macedonia passing south of Africa as a shortcut compared to the land route. Even Eratosthenes around 200 BC still assumed an extent of the landmass no further south than the Horn of Africa.

text: By the Roman imperial period the Horn of Africa was well-known to Mediterranean geographers. The trading post of Rhapta, described as "the last marketplace of Azania," may correspond to the coast of Tanzania. The Periplus of the Erythraean Sea, dated to the 1st century AD, appears to extend geographical knowledge further south, to Southeast Africa. Ptolemy's world map of the 2nd century is well aware that the African continent extents significantly further south than the Horn of Africa, but has no geographic detail south of the equator (it is unclear whether it is aware of the Gulf of Guinea)[5]

text: Arab slave trade[edit]

text: In the medieval period, the exploration of the interior of the Sahara and the Sahel as well as along the Swahili coast as far as Mozambique was the project of Muslim conquests and slave trade. It was at Mozambique that the Arab "clockwise" and the Portuguese "counter-clockwise" routes of exploration would meet at the end of the 15th century.

text: Following its 8th-century conquest of North Africa, Arab Muslims ventured into Sub-Saharan Africa first along the Nile Valley towards Nubia, and later also across the Sahara towards West Africa. They were interested in the trans-Saharan trade, especially in slaves. This expansion of Arab and Islamic culture was a gradual process, lasting throughout most of the Middle Ages. The Christian kingdoms of Nubia came under pressure from the 7th century, but they resisted for several centuries. The Kingdom of Makuria and Old Dongola collapsed by the beginning of the 14th century. A significant role in the spread of Islam in Africa was taken by Sufi orders during the 9th to 14th centuries, who spread south along trade routes between North Africa and the sub-Saharan kingdoms of Ghana and Mali. On the West African coast, they set up zawiyas on the shores of the River Niger. The Mali Empire became Islamic following the pilgrimage of Musa I of Mali in 1324. Timbuktu became an important center of Islamic culture south of the Sahara. Alodia, the last remnant of Christian Nubia, was destroyed by the Funj in 1504.

text: Early Portuguese expeditions[edit]

text: Portuguese explorer Prince Henry, known as the Navigator, was the first European to methodically explore Africa and the oceanic route to the Indies. From his residence in the Algarve region of southern Portugal, he directed successive expeditions to circumnavigate Africa and reach India. In 1420, Henry sent an expedition to secure the uninhabited but strategic island of Madeira. In 1425, he tried to secure the Canary Islands as well, but these were already under firm Castilian control. In 1431, another Portuguese expedition reached and annexed the Azores.

text: Naval charts of 1339 show that the Canary Islands were already known to Europeans. In 1341, Portuguese and Italian explorers prepared a joint expedition. In 1342 the Catalans organized an expedition captained by Francesc Desvalers to the Canary Islands that set sail from Majorca. In 1344, Pope Clement VI named French admiral Luis de la Cerda Prince of Fortune, and sent him to conquer the Canaries. In 1402, Jean de Bethencourt and Gadifer de la Salle sailed to conquer the Canary Islands but found them already plundered by the Castilians. Although they did conquer the isles, Bethencourt's nephew was forced to cede them to Castile in 1418.

text: In 1455 and 1456 two Italian explorers, Alvise Cadamosto from Venice and Antoniotto Usodimare from Genoa, together with an unnamed Portuguese captain and working for Prince Henry, the Navigator, of Portugal, followed the Gambia river, visiting the land of Senegal, while another Italian sailor from Genoa, Antonio de Noli, also on behalf of Prince Henry, explored the Bijagós islands, and, together with the Portuguese Diogo Gomes, the Cape Verde archipelago. Antonio de Noli, who became the first governor of Cape Verde (and the first European colonial governor in Sub-Saharan Africa), is also considered the discoverer of the First Islands of Cape Verde.[6]

text: Along the western and eastern coasts of Africa, progress was also steady; Portuguese sailors reached Cape Bojador in 1434 and Cape Blanco in 1441. In 1443, they built a fortress on the island of Arguin, in modern-day Mauritania, trading European wheat and cloth for African gold and slaves. It was the first time that the semi-mythic gold of the Sudan reached Europe without Muslim mediation. Most of the slaves were sent to Madeira, which became, after thorough deforestation, the first European plantation colony. Between 1444 and 1447, the Portuguese explored the coasts of Senegal, Gambia, and Guinea. In 1456, the Venetian captain Alvise Cadamosto, under Portuguese command, explored the islands of Cape Verde. In 1462, two years after Prince Henry's death, Portuguese sailors explored the Bissau islands and named Serra Leoa (Lioness Mountains).

text: In 1469, Fernão Gomes rented the rights of African exploration for five years. Under his direction, in 1471, the Portuguese reached modern Ghana and settled in A Mina (the mine), later renamed Elmina. They had finally reached a country with an abundance of gold, hence the historical name of "Gold Coast" that Elmina would eventually receive.

text: In 1472, Fernão do Pó discovered the island that would bear his name for centuries (now Bioko) and an estuary abundant in shrimp (Portuguese: camarão,), giving its name to Cameroon.

text: Soon after, the equator was crossed by Europeans . Portugal established a base in Sāo Tomé that, after 1485, was settled with criminals. After 1497, expelled Spanish and Portuguese Jews also found a safe haven there.

text: In 1482, Diogo Cão found the mouth of a large river and learned of the existence of a great kingdom, Kongo. In 1485, he explored the river upstream as well.

text: But the Portuguese wanted, above anything else, to find a route to India and kept trying to circumnavigate Africa. In 1485, the expedition of João Afonso d'Aveiros, with the German astronomer Martin of Behaim as part of the crew, explored the Bight of Benin (Kingdom of Benin), returning information about African king Ogane.

text: In 1488, Bartolomeu Dias and his pilot Pêro de Alenquer, after putting down a mutiny, turned a cape where they were caught by a storm, naming it Cape of Storms. They followed the coast for a while realizing that it kept going eastward with even some tendency to the north. Lacking supplies, they turned around with the conviction that the far end of Africa had finally been reached. Upon their return to Portugal the promising cape was renamed Cape of Good Hope.

text: Some years later, Christopher Columbus landed in America under rival Castilian command. Pope Alexander VI decreed the Inter caetera bull, dividing the non-Christian parts of the world between the two rival Catholic powers, Spain and Portugal.

text: Finally, in the years 1497 to 1498, Vasco da Gama, again with Alenquer as pilot, took a direct route to Cape of Good Hope, via St. Helena. He went beyond the farthest point reached by Dias and named the country Natal. Then he sailed northward, making land at Quelimane (Mozambique) and Mombasa, where he found Chinese traders, and Malindi (both in modern Kenya). In this town, he recruited an Arab pilot and set sail directly to Calicut. On August 28, 1498, King Manuel of Portugal informed the Pope of the good news that Portugal had reached India.

text: Egypt and Venice reacted to this news with hostility; from the Red Sea, they jointly attacked the Portuguese ships that traded with India. The Portuguese defeated these ships near Diu in 1509. The Ottoman Empire's indifferent reaction to Portuguese exploration left Portugal in almost exclusive control of trade through the Indian Ocean. They established many bases along the eastern coast of Africa except for Somalia (See Ajuran-Portuguese wars), The Portuguese also captured Aden in 1513.

text: One of the ships under command of Diogo Dias arrived at a coast that was not in East Africa. Two years later, a chart already showed an elongated island east of Africa that bore the name Madagascar. But only a century later, between 1613 and 1619, did the Portuguese explore the island in detail. They signed treaties with local chieftains and sent the first missionaries, who found it impossible to make locals believe in Hell, and were eventually expelled.

text: Early Modern history[edit]

text: Portuguese[edit]

text: Portuguese presence in Africa soon interfered with existing Arab trade interests. By 1583, the Portuguese established themselves in Zanzibar and on the Swahili coast. The Kingdom of Congo was converted to Christianity in 1495, its king taking the name of João I. The Portuguese also established their trade interests in the Kingdom of Mutapa in the 16th century, and in 1629 placed a puppet ruler on the throne.

text: The Portuguese (and later also the Dutch) also became involved in the local slave economy, supporting the state of the Jaggas, who performed slave raids in the Congo.[citation needed]

text: They also used the Kongo to weaken the neighbour realm of Ndongo, where Queen Nzinga put a fierce but eventually doomed resistance to Portuguese and Jagga ambitions. Portugal intervened militarily in these conflicts, creating the basis for their colony of Angola. In 1663, after another conflict, the royal crown of Kongo was sent to Lisbon. Nevertheless, a diminished Kongo Kingdom would still exist until 1885, when the last Manicongo, Pedro V, ceded his almost non-existent domain to Portugal.

text: The Portuguese dealt with the other major state of Southern Africa, the Monomotapa (in modern Zimbabwe), in a similar manner: Portugal intervened in a local war hoping to get abundant mineral riches, imposing a protectorate. But with the authority of the Monomotapa diminished by the foreign presence, anarchy took over. The local miners migrated and even buried the mines to prevent them from falling into Portuguese hands. When in 1693 the neighbouring Cangamires invaded the country, the Portuguese accepted their failure and retreated to the coast.

text: Dutch[edit]

text: Beginning in the 17th century, the Netherlands began exploring and colonizing Africa. While the Dutch were waging a long war of independence against Spain, Portugal had temporarily united with Spain, starting in 1580 and ending in 1640. As a result, the growing colonial ambitions of the Netherlands were mostly directed against Portugal.

text: For this purpose, two Dutch companies were founded: the West Indies Company, with power over all the Atlantic Ocean, and the East Indies Company, with power over the Indian Ocean.

text: The West India Company conquered Elmina in 1637 and Luanda in 1640. In 1648, they were expelled from Luanda by the Portuguese. Overall the Dutch built 16 forts in different places, including Gorée in Senegal, partly overtaking Portugal as the main slave-trading power.

text: The Dutch left a lasting impact in South Africa, a region ignored by Portugal that the Dutch eventually decided to use as station in their route to East Asia. Jan van Riebeeck founded Cape Town in 1652, starting the European exploration and colonization of South Africa.

text: Other early modern European presence[edit]

text: Almost at the same time as the Dutch, other European powers attempted to create their own outposts for the African slave trade.

text: As early as 1530, English merchant adventurers started trading in West Africa, coming into conflict with Portuguese troops. In 1581, Francis Drake reached the Cape of Good Hope. In 1663, the English built Fort James in Gambia. One year later, another English colonial expedition attempted to settle southern Madagascar, resulting in the death of most of the colonists. The English forts on the West African coast were eventually taken by the Dutch.

text: In 1626, the French Compagnie de l'Occident was created. This company expelled the Dutch from Senegal, making it the first French domain in Africa.

text: France also set her eyes on Madagascar, the island that had been used since 1527 as a stop in travels to India. In 1642, the French East India Company founded a settlement in southern Madagascar called Fort Dauphin. The commercial results of this settlement were scarce and, again, most of the settlers died. One of the survivors, Etienne de Flacourt, published a History of the Great Island of Madagascar and Relations, which was for a long time the main European source of information about the island. Further settlement attempts had no more success but, in 1667, François Martin led the first expedition to the Malgasy heartland, reaching Lake Alaotra. In 1665, France officially claimed Madagascar, under the name of Île Dauphine. However, little colonial activity would take place in Madagascar until the 19th century.

text: In 1657, Swedish merchants founded Cape Coast in modern Ghana, but were soon displaced by Denmark-Norway, founding Fort Christiansborg near modern-day Accra.

text: In 1677, King Frederick William I of Prussia sent an expedition to the western coast of Africa. The commander of the expedition, Captain Blonk, signed agreements with the chieftains of the Gold Coast. There, the Prussians built a fort named Gross Friederichsburg and restored the abandoned Portuguese fort of Arguin. But in 1720, the king decided to sell these bases to the Netherlands for 7,000 ducats and 12 slaves, six of them chained with pure gold chains.

text: The British expressed their interest by the formation in 1788 of The Association for Promoting the Discovery of the Interior Parts of Africa. The individuals who formed this club were inspired in part by the Scotsman James Bruce, who had ventured to Ethiopia in 1769 and reached the source of the Blue Nile.

text: Overall, European exploration of Africa in the 17th and 18th centuries was very limited. Instead they were focused on the slave trade, which only required coastal bases and items to trade. The real exploration of the African interior would start well into the 19th century.

text: The 19th century[edit]

text: Although the Napoleonic Wars distracted the attention of Europe from exploratory work in Africa, those wars nevertheless exercised great influence on the future of the continent, both in Egypt and South Africa. The occupation of Egypt (1798–1803), first by France and then by Great Britain, resulted in an effort by the Ottoman Empire to regain direct control over that country. In 1811, Mehemet Ali established an almost independent state, and from 1820 onward established Egyptian rule over the eastern Sudan. In South Africa, the struggle with Napoleon caused the United Kingdom to take possession of the Dutch settlements at the Cape. In 1814, Cape Colony, which had been continuously occupied by British troops since 1806, was formally ceded to the British crown.

text: Meanwhile, considerable changes had been made in other parts of the continent. The occupation of Algiers by France in 1830 put an end to the piracy of the Barbary states. Egyptian authority continued to expand southward, with the consequent additions to knowledge of the Nile. The city of Zanzibar, on the island of that name, rapidly attained importance. Accounts of a vast inland sea, and the discovery of the snow-clad mountains of Kilimanjaro in 1840–1848, stimulated the desire for further knowledge about Africa in Europe.

text: In the mid-19th century, Protestant missions were carrying on active missionary work on the Guinea coast, in South Africa and in the Zanzibar dominions. Missionaries visited little-known regions and peoples, and in many instances became explorers and pioneers of trade and empire. David Livingstone, a Scottish missionary, had been engaged since 1840 in work north of the Orange River. In 1849, Livingstone crossed the Kalahari Desert from south to north and reached Lake Ngami. Between 1851 and 1856, he traversed the continent from west to east, discovering the great waterways of the upper Zambezi River. In November 1855, Livingstone became the first European to see the famous Victoria Falls, named after the Queen of the United Kingdom. From 1858 to 1864, the lower Zambezi, the Shire River and Lake Nyasa were explored by Livingstone. Nyasa had been first reached by the confidential slave of António da Silva Porto, a Portuguese trader established at Bié in Angola, who crossed Africa during 1853–1856 from Benguella to the mouth of the Rovuma. A prime goal for explorers was to locate the source of the River Nile. Expeditions by Burton and Speke (1857–1858) and Speke and Grant (1863) located Lake Tanganyika and Lake Victoria. It was eventually proved to be the latter from which the Nile flowed.

text: Henry Morton Stanley, who had in 1871 succeeded in finding and succouring Livingstone (originating the famous line "Dr. Livingstone, I presume"), started again for Zanzibar in 1874. In one of the most memorable of all exploring expeditions in Africa, Stanley circumnavigated Victoria Nyanza (Lake Victoria) and Lake Tanganyika. Striking farther inland to the Lualaba, he followed that river down to the Atlantic Ocean—which he reached in August 1877—and proved it to be the Congo.

text: In 1895, the British South Africa Company hired the American scout Frederick Russell Burnham to look for minerals and ways to improve river navigation in the central and southern Africa region. Burnham oversaw and led the Northern Territories British South Africa Exploration Company expedition that first established that major copper deposits existed north of the Zambezi in North-Eastern Rhodesia. Along the Kafue River, Burnham saw many similarities to copper deposits he had worked in the United States, and he encountered native peoples wearing copper bracelets.[7] Copper rapidly became the primary export of Central Africa and it remains essential to the economy even today.

text: Explorers were also active in other parts of the continent. Southern Morocco, the Sahara and the Sudan were traversed in many directions between 1860 and 1875 by Georg Schweinfurth and Gustav Nachtigal.[8] These travellers not only added considerably to geographical knowledge, but obtained invaluable information concerning the people, languages and natural history of the countries in which they sojourned. Among the discoveries of Schweinfurth was one that confirmed Greek legends of the existence beyond Egypt of a "pygmy race". But the first western discoverer of the pygmies of Central Africa was Paul Du Chaillu, who found them in the Ogowe district of the west coast in 1865, five years before Schweinfurth's first meeting with them. Du Chaillu had previously, through journeys in the Gabon region between 1855 and 1859, made popular in Europe the knowledge of the existence of the gorilla, whose existence was thought to be as legendary as that of the Pygmies of Aristotle.

text: List of Africa explorers[edit]

text: This article contains embedded lists that may be poorly defined, unverified or indiscriminate. Please help to clean it up to meet Wikipedia's quality standards. Where appropriate, incorporate items into the main body of the article. (October 2014)

tag: table

text: 15th century[edit]

text:
Diogo Cão
 Diogo de Azambuja
 Bartolomeu Dias
 Pêro de Alenquer
 João Infante
 João Grego
 Álvaro Martins
 Pêro Dias
 Gil Eanes
 Nuno Tristão
 Antão Gonçalves
 Dinis Dias
 Álvaro Fernandes
 Pêro de Sintra
 Fernão do Pó
 Alvise Cadamosto (Venetian born)
 António de Noli (Genoese born)
 Diogo Gomes
 Álvaro Caminha
 João de Santarém
 Pedro Escobar
 Duarte Pacheco Pereira
 Lopes Gonçalves (and Atlantic Ocean)

tag: ul

text: 15th/16th century[edit]

text:
Vasco da Gama (and discovered sea route to India)
 Diogo Dias (and Indian Ocean, discovered Madagascar)
 Pêro da Covilhã (15th/16th century diplomat and explorer in Ethiopia)
 Pedro Álvares Cabral (discovered Brazil, explored India along the African coast)
 Sancho de Tovar and Vicente Pegado among others (also among the first Europeans ever to contemplate and to describe the ruins of Great Zimbabwe, then referred to by the Portuguese as Monomotapa).

text: 16th century[edit]

text:
Paulo Dias de Novais
 António Fernandes (he travalled to Monomotapa and beyond, exploring most of the present day Zimbabwe and possibly northeastern South Africa)[9]
 Lourenço Marques (trader and explorer in East Africa)
 Francisco Álvares (missionary and explorer in Ethiopia)
 Gonçalo da Silveira (jesuit missionary, travalled up the Zambezi River to the capital of the Monomotapa which appears to have been the N'Pande kraal, close by the M'Zingesi River, a southern tributary of the Zambezi)

text: 18th century[edit]

text: Francisco de Lacerda (explorer in Zambia)

text: 19th century[edit]

text:
Heinrich Barth
 Pierre Savorgnan de Brazza (Italian born)
 Johann Ludwig Burckhardt
 Frederick Russell Burnham (1861-1947), an American explorer of south, west, central, and east Africa.
 Richard Francis Burton (1821–1890) (African Great Lakes)
 René Caillié
 Hermenegildo Capelo
 Roberto Ivens
 Candido José da Costa Cardoso (visited Lake Malawi [also known as Lake Nyasa or Lake Niassa] in 1846)
 Paul Du Chaillu
 Hugh Clapperton (1788–1827), explored west and central Africa
 'Victor de Compiègne'
 Dixon Denham (1786–1828), explored west central Africa.
 James Frederic Elton (1840–1877)
 Emil Holub
 Ignatius Knoblecher (1819–1858), explored the White Nile basin
 Alexander Gordon Laing (1793–1826)
 Richard Lemon Lander (1804–1834)
 Oskar Lenz (1848–1925), expeditions in 1879-80 (trans-Sahara) and 1885-87 (Congo)
 David Livingstone (1813–1873)

Emin Pasha Relief Expedition

 Frederick Lugard (1858–1945)
 Serpa Pinto (soldier and colonizer of Africa)
 António da Silva Porto
 Arthur Henry Neumann (1850-1907)
 Mungo Park (explorer) (1771–1806)
 Georg Schweinfurth (Latvian born)
 Frederick Courtney Selous (1851-1917)
 Henry Morton Stanley (1841–1904) (Welsh born)
 William Edgar Geil (1 October 1865, Doylestown, Pennsylvania – 11 April 1925, Venice)
 John Hanning Speke (1827–1864) (discovered the source of the Nile)
 James Hingston Tuckey (1776–1816) (Irish born)

text: Early 20th century[edit]

text:
Jan Czekanowski
 William Edgar Geil
 Kazimierz Nowak


document_title: Standing on a Beach

question_text: who is the man on the cover of staring at the sea

text: Standing on a Beach

text: Release formats[edit]

text: The album was released in three formats: vinyl record, compact disc and audio cassette.

text: The vinyl edition is a collection of all 13 of The Cure's commercially released singles up to that point in chronological order. "10:15 Saturday Night" was dropped though, possibly because it was only released in France.

text: The CD edition features the same tracks as the vinyl edition, but also includes an extra track from four of the band's albums. The four songs, although not released as singles, all had music videos made for them.

text: The cassette edition features the same tracks as the vinyl edition, but also contains all of the band's B-sides that had not, to that point, received a long-play release. This excludes "10:15 Saturday Night" from the "Killing an Arab" single, which was released on the Three Imaginary Boys album, "Plastic Passion" from the "Boys Don't Cry" single, which was released on the Boys Don't Cry album, and the five B-sides from the "Let's Go to Bed", "The Walk" and "The Love Cats" singles, which were released on the Japanese Whispers compilation album. However, the B-side "Mr. Pink Eyes" from the 12" version of "The Lovecats" was omitted from Japanese Whispers, and so was included on this release.

text: These releases were accompanied by a VHS and laserdisc release, a music video collection titled Staring at the Sea: The Images with the same setlist as the CD version of the album.

text: All the B-sides on the cassette edition were also later released on the first disc of the Join the Dots compilation in 2004.

text: The album has been certified 2x platinum in the U.S.

text: Also missing is the special "Lament" Flexipop single from 1982, as this was not a proper single, and "I'm a Cult Hero" from 1979, probably because it was released under a different band name (Cult Hero).

text: Album art[edit]

text: The man featured on the album cover was not a member of the Cure; he was chosen because his appearance fit the desired aesthetic of the album. His name is John Button, and was at the time a retired fisherman. He also appeared in the music video for "Killing an Arab". According to the band's 2005 biography by Jeff Apter, when asked why he agreed to lend his face to the band's media, Button's answer was, "If I can help these youngsters break through, after all, why not?"[7] He also reportedly said that he would buy a player and listen to one of the band's songs "out of curiosity, just to see".[8]

text: Track listing[edit]

text: Vinyl edition[edit]

text: Side A

text:
"Killing an Arab" (Robert Smith, Lol Tolhurst, Michael Dempsey) – 2:22
"Boys Don't Cry" (Smith, Tolhurst, Dempsey) – 2:35
"Jumping Someone Else's Train" (Smith, Tolhurst, Dempsey) – 2:54 (from Boys Don't Cry, 1980)
"A Forest" (Smith, Tolhurst, Simon Gallup, Matthieu Hartley) – 4:53 (from Seventeen Seconds, 1980)
"Primary" (Smith, Tolhurst, Gallup) – 3:33 (from Faith, 1981)
"Charlotte Sometimes" (Smith, Tolhurst, Gallup) – 4:13
"The Hanging Garden" (Smith, Tolhurst, Gallup) – 4:21 (from Pornography, 1982)

text: Side B

text:
"Let's Go to Bed" (Smith, Tolhurst) – 3:33
"The Walk" (Smith, Tolhurst) – 3:28
"The Love Cats" (Smith) – 3:38 (from Japanese Whispers, 1983)
"The Caterpillar" (Smith, Tolhurst) – 3:38 (from The Top, 1984)
"In Between Days" (Smith) – 2:56 (from The Head on the Door, 1985)
"Close to Me" (Smith) – 3:39 (from The Head on the Door, 1985)

text: CD/video editions[edit]

text:
"Killing an Arab" (Smith, Tolhurst, Dempsey) – 2:22
"10:15 Saturday Night" (Smith, Tolhurst, Dempsey) – 3:37 (from Three Imaginary Boys, 1979)
"Boys Don't Cry" (Smith, Tolhurst, Dempsey) – 2:35
"Jumping Someone Else's Train" (Smith, Tolhurst, Dempsey) – 2:57
"A Forest" (Smith, Tolhurst, Gallup, Hartley) – 4:53 (from Seventeen Seconds, 1980)
"Play for Today" (Smith, Tolhurst, Gallup, Hartley) – 3:42 (from Seventeen Seconds, 1980)
"Primary" (Smith, Tolhurst, Gallup) – 3:33 (from Faith, 1981)
"Other Voices" (Smith, Tolhurst, Gallup) – 4:26 (from Faith, 1981)
"Charlotte Sometimes" (Smith, Tolhurst, Gallup) – 4:13
"The Hanging Garden" (Smith, Tolhurst, Gallup) – 4:21 (from Pornography, 1982)
"Let's Go to Bed" (Smith, Tolhurst) – 3:33
"The Walk" (Smith, Tolhurst) – 3:28
"The Love Cats" (Smith) – 3:38
"The Caterpillar" (Smith, Tolhurst) – 3:38 (from The Top, 1984)
"In Between Days" (Smith) – 2:56 (from The Head on the Door, 1985)
"Close to Me" (Smith) – 3:39 (from The Head on the Door, 1985)
"A Night Like This" (Smith) – 4:11 (from The Head on the Door, 1985)

text: Cassette edition[edit]

text: Side 1 - The singles[edit]

text:
"Killing an Arab" (Smith, Tolhurst, Dempsey) – 2:22
"Boys Don't Cry" (Smith, Tolhurst, Dempsey) – 2:35
"Jumping Someone Else's Train" (Smith, Tolhurst, Dempsey) – 2:54
"A Forest" (Smith) – 4:53
"Primary" (Smith, Tolhurst, Gallup) – 3:33
"Charlotte Sometimes" (Smith, Tolhurst, Gallup) – 4:13
"The Hanging Garden" (Smith, Tolhurst, Gallup) – 4:21
"Let's Go to Bed" (Smith, Tolhurst) – 3:33
"The Walk" (Smith, Tolhurst) – 3:28
"The Lovecats" (Smith) – 3:38
"The Caterpillar" (Smith, Tolhurst) – 3:38
"In Between Days" (Smith) – 2:56
"Close to Me" (Smith) – 3:39

text: Side 2 - The B-sides[edit]

text:
"I'm Cold" (Smith, Tolhurst, Dempsey) – 2:47 (from "Jumping Someone Else's Train")
"Another Journey By Train" (Smith, Gallup, Tolhurst, Hartley) – 3:04 (from "A Forest")
"Descent" (Smith, Gallup, Tolhurst) – 3:07 (from "Primary")
"Splintered in Her Head" (Smith, Gallup, Tolhurst) – 5:16 (from "Charlotte Sometimes")
"Mr Pink Eyes" (Smith, Tolhurst) – 2:42 (from "The Love Cats")
"Happy the Man" (Smith) – 2:45 (from "The Caterpillar")
"Throw Your Foot" (Smith) – 3:33 (from "The Caterpillar")
"The Exploding Boy" (Smith) – 2:52 (from "In Between Days")
"A Few Hours After This" (Smith) – 2:26 (from "In Between Days")
"A Man Inside My Mouth" (Smith) – 3:05 (from "Close to Me"/Half an Octopuss)
"Stop Dead" (Smith) – 4:02 (from "In Between Days"/"Close to Me"/Half an Octopuss)
"New Day" (Smith, Tolhurst) – 4:08 (from Half an Octopuss)

text: Comparison[edit]

text: Presented here is a comparison showing in what format each of the 29 songs on the album can be found, with the position number of that song on that particular format.

text:
Song
Vinyl LP
CD and VHS
Cassette

"10:15 Saturday Night"
7001140000000000000♠
2
7001260000000000000♠

"A Few Hours After This"
7001260000000000000♠
7001260000000000000♠
22

"A Forest"
4
5
4

"A Man Inside My Mouth"
7001270000000000000♠
7001270000000000000♠
23

"A Night Like This"
7001170000000000000♠
17
7001290000000000000♠

"Another Journey By Train"
7001190000000000000♠
7001190000000000000♠
15

"Boys Don't Cry"
2
3
2

"The Caterpillar"
11
14
11

"Charlotte Sometimes"
6
9
6

"Close to Me"
13
16
13

"Descent"
7001200000000000000♠
7001200000000000000♠
16

"The Exploding Boy"
7001250000000000000♠
7001250000000000000♠
21

"The Hanging Garden"
7
10
7

"Happy the Man"
7001230000000000000♠
7001230000000000000♠
19

"I'm Cold"
7001180000000000000♠
7001180000000000000♠
14

"In Between Days"
12
15
12

"Jumping Someone Else's Train"
3
4
3

"Killing an Arab"
1
1
1

"Let's Go to Bed"
8
11
8

"The Love Cats"
10
13
10

"Mr Pink Eyes"
7001220000000000000♠
7001220000000000000♠
18

"New Day"
7001290000000000000♠
7001290000000000000♠
25

"Other Voices"
7001160000000000000♠
8
7001280000000000000♠

"Play for Today"
7001150000000000000♠
6
7001270000000000000♠

"Primary"
5
7
5

"Splintered in Her Head"
7001210000000000000♠
7001210000000000000♠
17

"Stop Dead"
7001280000000000000♠
7001280000000000000♠
24

"Throw Your Foot"
7001240000000000000♠
7001240000000000000♠
20

"The Walk"
9
12
9