YOUR MY HONEY

Honey is a sweet and viscous fluid produced by honey bees (and some other species), and derived from the nectar of flowers. According to the United States National Honey Board and various international food regulations, "honey stipulates a pure product that does not allow for the addition of any other substance...this includes, but is not limited to, water or other sweeteners". This article refers exclusively to the honey produced by honey bees (the genus Apis); honey produced by other bees or other insects has very different properties.

Honey is significantly sweeter than table sugar and has attractive chemical properties for baking. Honey has a distinctive flavor which leads some people to prefer it over sugar and other sweeteners.

Most microorganisms do not grow in honey because of its low water activity of 0.6. However, it is important to note that honey frequently contains dormant endospores of the bacteria Clostridium botulinum, which can be dangerous to infants as the endospores can transform into toxin-producing bacteria in the infant's immature intestinal tract, leading to illness and even death.

The study of pollens and spores in raw honey (melissopalynology) can determine floral sources of honey. Because bees carry an electrostatic charge, and can attract other particles, the same techniques of melissopalynology can be used in area environmental studies of radioactive particles, dust, or particulate pollution.

A main effect of bees collecting nectar to make honey is pollination, which is crucial for flowering plants.

The beekeeper encourages overproduction of honey within the hive so that the excess can be taken without endangering the bees. When sources of foods for the bees are short the beekeeper may have to give the bees supplementary nutrition.

Honey is laid down by bees as a food source. In cold weather or when food sources are scarce, bees use their stored honey as their source of energy. By contriving for the bee swarm to make its home in a hive, people have been able to semi-domesticate the insects. In the hive there are three types of bee: the single queen bee, a seasonally variable number of drone bees to fertilize new queens, and some 20,000 to 40,000 worker bees. The worker bees raise larvae and collect the nectar that will become honey in the hive. They go out, collect the sugar-rich flower nectar and return to the hive. As they leave the flower, bees release Nasonov pheromones. These enable other bees to find their way to the site by smell. Honeybees also release Nasonov pheromones at the entrance to the hive, which enables returning bees to return to the proper hive. In the hive the bees use their "honey stomachs" to ingest and regurgitate the nectar a number of times until it is partially digested. It is then stored in the honeycomb. Nectar is high in both water content and natural yeasts which, unchecked, would cause the sugars in the nectar to ferment. After the final regurgitation, the honeycomb is left unsealed. Bees inside the hive fan their wings, creating a strong draft across the honeycomb which enhances evaporation of much of the water from the nectar. The reduction in water content, which raises the sugar concentration, prevents fermentation. Ripe honey, as removed from the hive by the beekeeper, has a long shelf life and will not ferment.

Honey is a mixture of sugars and other compounds. With respect to carbohydrates, honey is mainly fructose (about 38.5%) and glucose (about 31.0%)[3], making it similar to the synthetically produced inverted sugar syrup which is approximately 47% fructose, 47% glucose and 5% sucrose. Honey's remaining carbohydrates include maltose, sucrose, and other complex carbohydrates.

Honey contains trace amounts of several vitamins and minerals. As with all nutritive sweeteners, honey is mostly sugars and is not a significant source of vitamins or minerals.

Honey also contains tiny amounts of several compounds thought to function as antioxidants, including chrysin, pinobanksin, vitamin C, catalase, and pinocembrin.

The specific composition of any batch of honey will depend largely on the mix of flowers available to the bees that produced the honey.

Honey has a density of about 1.36 kg/liter (40% denser than water).

Typical honey analysis

* Fructose: 38.0%
* Glucose: 31.0%
* Sucrose: 1.0%
* Water: 17.0%
* Other sugars: 9.0% (maltose, melezitose)
* Ash: 0.17%
* Other: 3.38%

The analysis of the sugar content of honey is used for detecting adulteration.

* Comb honey Honey sold still in the original bees' wax comb. Comb honey was once packaged by installing a wooden framework in special honey supers, but this labor intensive method is being replaced by plastic rings or cartridges. With the new approach, a clear cover is usually fitted onto the cartridge after removal from the hive so customers can see the product[citation needed].
* Certified Organic Honey, according to the USDA, organic honey is quite rare to find because most beekeepers "routinely use sulfa compounds and antibiotics to control bee diseases, carbolic acid to remove honey from the hive and calcium cyanide to kill colonies before extracting the honey, not to mention that conventional honeybees gather nectar from plants that have been sprayed with pesticides."
* Raw honey Honey as it exists in the beehive or as obtained by extraction, settling or straining without adding heat above 120 degrees fahrenheit. Raw honey contains some pollen and may contain small particles of wax. Local raw honey is sought after by allergy sufferers as the pollen impurities are thought to lessen the sensitivity to hay fever.
* Chunk honey Honey packed in widemouth containers consisting of one or more pieces of comb honey surrounded by extracted liquid honey.
* Strained honey or Honey which has been passed through a mesh material to remove particulate material (pieces of wax, propolis, other defects) without removing pollen, minerals or valuable enzymes. Preferred by the health food trade - it may have a cloudy appearance due to the included pollen, and it also tends to crystallize more quickly than ultrafiltered honey.
* Ultrafiltered honey Honey processed by very fine filtration under high pressure to remove all extraneous solids and pollen grains. The process typically heats honey to 150-170 degrees to more easily pass through the fine filter. Ultrafiltered honey is very clear and has a longer shelf life, because it crystallizes more slowly due to the high temperatures breaking down any sugar seed crystals, making it preferred by the supermarket trade. Ultrafiltration eliminates nutritionally valuable enzymes, such as diastase and invertase.
* Heat-Treated honey Heat-treatment after extraction reduces the moisture level and destroys yeast cells. Heating liquefies crystals in the honey, too. Heat-exposure does also result in product deterioration, as it increases the level of hydroxymethylfurfural (HMF) and reduces enzyme (e.g. diastase) activity. The heat does also affect sensory qualities and reduces the freshness. Heat processing can darken the natural honey color (browning), too.
* Ultrasonicated honey Ultrasonication is a non-thermal processing alternative for honey. When honey is exposed to ultrasonication, most of the yeast cells are destroyed. Yeast cells that survive sonication generally lose their ability to grow. This reduces the rate of honey fermentation substantially. Ultrasonication does also eliminate existing crystals and inhibit further crystallization in honey. Ultrasonically aided liquefaction can work at substantially lower temperatures of approx. 35 °C and can reduce liquefaction time to less than 30 seconds.


Due to its unique composition and the complex processing of nectar by the bees which changes its chemical properties, honey is suitable for long term preservation and is easily assimilated even after long conservation. History knows examples of honey preservation for decades, and even centuries. "...small residues of edible honey have even been found in the pharaoh's tombs..."[22]

A number of special prerequisites is, however, necessary to achieve the conservation periods of this order. These might include sealing the product in vessels of chosen material, kept in a favorable environment of specific humidity, temperature etc. An example of natural sealing of the honey with wax by the bees in little separated honey comb cells could be taken for reference.

When conventional preservation methods are applied, it is not recommended to preserve the honey for longer than 2 (maximum 3) years. As the honey has a strong tendency to absorb outside smells, it is advisable to keep it in clean, hermetically sealed vessels. It is also advisable to keep it in darkened (not lucid) vessels, or in dark store-places. When the honey remains in direct sunlight for about one day its lysozyme (antibacterial albuminous enzyme) is being destroyed[citation needed]. Honey should also be protected from oxygen inflow – the accelerated crystallization is brought about by it. Optimal preservation temperature is +4-10°C. The store-place should be dark and dry, preventing the honey from absorbing the moisture. When excessive moisture is soaked up by the honey, it might start fermenting. "Bee honey can absorb the moisture from the air, therefore it might ferment in a damp place"[23]

"Exposure to fresh air brings about the soaking up of external smells, oxygen and moisture, which cause fundamental chemical change of the product - decay of valuable amino acids, vitamins, enzymes and "antibiotics". The light has a similar influence."[24]

The acacia honey is known to be more resistant against crystallization. "The acacia honey would not crystallize (as quick as other types)..."[25]

Due to the above reasons (high tendency to absorb outside smells and moisture) it is not advisable to preserve the honey in a fridge, especially together with other foods and products.

Honey is considered to gradually become toxic when preserved in metal containers. "Honey must not be preserved in metal containers, because the acids contained in its structure may cause oxidation. This leads to increased content of heavy metals in honey and decreases the amount of valuable healthy ingredients. Such a honey may cause obnoxious sensations in the stomach and even bring about a poisoning..."[26] It used to be preserved in ceramic and wooden containers in ancient times. Glass bottles are recommended nowadays. "The wooden vessels of coniferous wood are not suitable for honey preservation (honey soaks up the coniferous smell in such vessels). In the oak wood vessels honey grows black."[27]

Traditionally honey was preserved in deep cellars, but not together with wine or other products. It is considered even more sensitive to the store-place conditions than the best wines.

Honey should not be heated above 40°С (104°F) [28]. See also [29].

"The best honey is in the uncut honey combs. After being pumped out from there it is very vulnerable, and the main losses of quality take place during preservation and distribution. Heating up to 37°С causes loss of nearly 200 components, part of which are antibacterial. Heating up to 40°С destroys the invertase - the main bee enzyme, thanks to which the nectar becomes honey; heating up to 50°С turns the honey into caramel (the most valuable honey sugars become analogous to synthetic sugar). Generally any larger temperature fluctuation (10°С is ideal for preservation of ripe honey) causes decay."[30]

The high quality natural honey can be distinguished by its fragrance and taste. The best period to stock up on honey is in summer, when it is being collected in large quantities. The ripe, freshly collected, high quality honey at 20°C (68°F) flows from the knife in a straight squirt, without breaking into separate drops. After falling down the honey should form a clear hillock. A saying goes: “the honey rustles and glues like viscose”. The ripe honey is being collected from the sealed honey combs, therefore it should always be of high quality.

The honey should not lay down in layers. If this is a case, it indicates the excessive humidity (over 20%) of the product, and such a honey would not be suitable for long term preservation.

A fluffy thin layer on the surface of the honey (like a white foam), or marble-coloured and white spots in crystallized honey at the wallsides of the bottle are caused by filling of liquid honey with subsequent sealing – the air bubbles are surfacing and part of them is concentrated at the wallsides. This is an indication of a high quality honey, which was filled without pasteurization (heating).

If the honey is transparent, burning with amber-like colours, then (unless it is very fresh) it has most likely been heated and is of little value. Transparent and reluctant to thicken honey can also indicate its being a result of feeding the bees with sugar syrup or even sugar itself, which is bad both for the bees and for the honey they produce, as naturally they are supposed to feed on flower nectar.

A true honey that is at least one month old is usually of demure (not trans-lucid) colours.

Due to the natural presence of botulinum endospores in honey, children under one year of age should not be given honey. The more developed digestive systems of older children and adults generally destroy the spores. Infants, however, can contract botulism from honey.[47]

Honey produced from the flowers of rhododendrons, mountain laurels, sheep laurel and azaleas may cause honey intoxication. Symptoms include dizziness, weakness, excessive perspiration, nausea and vomiting. Less commonly, low blood pressure, shock, heart rhythm irregularities and convulsions may occur, with rare cases resulting in death. Honey intoxication is more likely when using "natural" unprocessed honey and honey from farmers who may have a small number of hives. Commercial processing, with pooling of honey from numerous sources generally dilutes any toxins.[48]

Toxic honey may also result when bees are in close proximity to tutu bushes (Coriaria arborea) and the vine hopper insect (Scolypopa australis).[citation needed] Both are found throughout New Zealand. Bees gather honeydew produced by the vine hopper insects feeding on the tutu plant. This introduces the poison tutin into honey. Only a few areas in New Zealand (Coromandel Peninsula, Eastern Bay of Plenty and the Marlborough Sound) frequently produce toxic honey. Symptoms of tutin poisoning include vomiting, delirium, giddiness, increased excitability, stupor, coma and violent convulsions. As little as one teaspoon of toxic honey may produce severe effects in humans.[citation needed] In order to reduce the risk of tutin poisoning, humans should not eat honey taken from feral hives in the risk areas of New Zealand. Since December 2001, New Zealand beekeepers have been required to reduce the risk of producing toxic honey by closely monitoring tutu, vine hopper, and foraging conditions within 3 km of their apiary.

BIOGAS THE NEXT GENERATION OF ALTERNATIVE FUEL FOR THE WORLD

Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Biogas is comprised primarily of methane and carbon dioxide. Biogas originates from biogenic material and is a type of biofuel. Biogas is a product of the anaerobic digestion or fermentation of biodegradable materials such as manure or sewage, municipal waste, and energy crops. Other types of biogas include wood gas which is created by gasification of wood or other biomass.

The methane in biogas gives it the ability to be used as a fuel. The combustion of which releases energy. In developing countries biogas can be used as a low-cost fuel for cooking. It can also be utilised in modern waste management facilities where it can be used in gas engines to generate electricity. Biogas is a renewable fuel and electricity produced from it can be used to attract renewable energy subsidies in some parts of the world.

Depending on where it is produced, biogas can also be called swamp, marsh, landfill or digester gas. A biogas plant is the name often given to an anaerobic digester that treats farm wastes or energy crops.

Biogas can be produced utilising anaerobic digesters. These plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste.

Landfill gas is produced by organic waste decomposing under anaerobic conditions in a landfill. The waste is covered and compressed mechanically and by the weight of the material that is deposited from above. This material prevents oxygen from accessing the waste and anaerobic microbes thrive. This gas builds up and is slowly released into the atmosphere if the landfill site has not been engineered to capture the gas. Landfill gas is hazardous for three key reasons. Landfill gas becomes explosive when it escapes from the landfill and mixes with oxygen within lower and higher explosive limits. The methane in biogas forms explosive mixtures in air. The lower explosive limit is 5% methane and the upper explosive limit is 15% methane. The methane contained within biogas is 20 times more potent as a greenhouse gas than carbon dioxide. Therefore uncontained landfill gas which escapes into the atmosphere significantly contributes to the effects of global warming. In addition to this volatile organic compounds (VOCs) contained within landfill gas contribute to the formation of photochemical smog.

The composition of biogas varies depending upon the origin of the anaerobic digestion process. Landfill gas typically has methane concentrations around 50%. Advanced waste treatment technologies can produce biogas with 55-75%CH4.

In some cases biogas contains siloxanes. These siloxanes are formed from the anaerobic decomposition of materials commonly found in soaps and detergents. During combustion of biogas containing siloxanes, silicon is released and can combine with free oxygen or various other elements in the combustion gas. Deposits are formed containing mostly silica (SiO2) or silicates (SixOy) and can also contain calcium, sulphur, zinc, phosphorus. These white mineral deposits build to a surface thickness of several millimetres and must be removed by chemical or mechanical means.

Biogas can be utilised for electricity production, space heating, water heating and process heating. If compressed, it can replace compressed natural gas for use in vehicles, where it can fuel an internal combustion engine or fuel cells.

Methane within biogas can be concentrated to the same standards as natural gas, when it is, it is called biomethane. If the local gas network permits it the producer of the biogas may be able to utilise the local gas distribution networks. Gas must be very clean to reach pipeline quality, and must be of the correct composition for the local distribution network to accept. Carbon dioxide, Water, hydrogen sulfide and particulates must be removed if present. If concentrated and compressed it can also be used in vehicle transportation. Compressed biogas is becoming widely used in Sweden, Switzerland and Germany. A biogas-powered train has been in service in Sweden since 2005.

Bates' and his biogas car were the subject of a short documentary film called 'Sweet as a Nut' in 1974, at which point he had run his car for 17 years on gas he had produced by processing pig manure. Bates, an inventor lived in Devon, UK and in the film talks through the simple process and benefits of running a car on biogas. The conversion was simply made with an adapter attached to any combustion engine.

In India biogas produced from the anaerobic digestion of manure in small-scale digestion facilites is called Gober gas. In India biogas is generated at an estimated 2 million+ household facilites. The digester is an airtight circular pit made of concrete with a pipe connection. The manure is directed to the pit, usually directly from the cattle shed. The pit is then filled with a required quantity of wastewater. The gas pipe is connected to the kitchen fire place through control valves. The combustion of the biogas produced in this manner flammable has very little odour or smoke. Owing to its simplicity in implementation and use of cheap raw materials in the villages it is one of the most environmentally sound energy source for the rural needs.

The Biogas Support Program in Nepal has intalled over 100,000 biogas plants in rural areas.

Vietnam’s Biogas Programme for Animal Husbandry Sector has led to the installation of over 20,000 plants throughout that country.

Biogas is also in use in rural Costa Rica.

In Colombia experiments with diesel engines-generator sets partially fuelled by biogas demonstrated that biogas could be used for power generation, reducing elecricity costs by 40% compared with purchase from the regional utility.

Biogasmax is a large-scale integrated project funded by the European Commission in order to ensure the market penetration of biogas as a vehicle fuel. The European Biogasmax project creates a network of biogas-related demonstrations in order to share best practices in managing sustainable urban transportation. The cities involved in Biogasmax include Stockholm, Gothenburg, Lille, Rome and Berne.

The research and development projects carried out in the context of BIOGASMAX are closely tied to the following four main fields of technological activities:

Production of biogas from various types of urban and organic waste; Upgrading of biogas to a high-quality fuel; Distribution for transport and injection into natural gas grids; Use in vehicles to increase the number of biomethane-fueled vehicles.

The European Union presently has some of the strictest legislation regarding waste management and landfill sites called the Landfill Directive. The United States legislates against landfill gas as it contains these VOCs. The United States Clean Air Act and Title 40 of the Code of Federal Regulations (CFR) requires landfill owners to estimate the quantity of non-methane organic compounds (NMOCs) emitted. If the estimated NMOC emissions exceeds 50 tonnes per year the landfill owner is required to collect the landfill gas and treat it to remove the entrained NMOCs. Treatment of the landfill gas is usually by combustion. Because of the remoteness of landfill sites it is sometimes not economically feasible to produce electricity from the gas.

AMAZON RIVER

The Amazon River or River Amazon (Portuguese: Rio Amazonas; Spanish: Río Amazonas) of South America is the largest river in the world by volume, with a total river flow greater than the next top ten largest rivers flowing into the ocean combined.

The Amazon River accounts for approximately 1/5 of total world's river flow, and it has the largest drainage basin in the world. There is an ongoing dispute regarding its length, and along with the Nile it is one of the contenders for the position as the longest river in the world. Because of its vast dimensions, it is sometimes called The River Sea (o rio-mar in Portuguese), and at no point is it crossed by bridges. In 1500, Vicente Yañez Pinzón was the first European to sail into the river. Pinzón called the river flow "Río Santa María de la Mar Dulce", later shortened to "Mar Dulce" (sweet sea).

The Amazon River or River Amazon (Portuguese: Rio Amazonas; Spanish: Río Amazonas) of South America is the largest river in the world by volume, with a total river flow greater than the next top ten largest rivers flowing into the ocean combined.

The Amazon River accounts for approximately 1/5 of total world's river flow, and it has the largest drainage basin in the world. There is an ongoing dispute regarding its length, and along with the Nile it is one of the contenders for the position as the longest river in the world. Because of its vast dimensions, it is sometimes called The River Sea (o rio-mar in Portuguese), and at no point is it crossed by bridges.[1] In 1500, Vicente Yañez Pinzón was the first European to sail into the river. Pinzón called the river flow "Río Santa María de la Mar Dulce", later shortened to "Mar Dulce" (sweet sea).

Today, the Upper Amazon has a series of major river systems in Peru (many of which are alike in Ecuador) that flow North and South into the Marañón and Amazon River. Among others, these include the following rivers: Morona, Pastaza, Nucuray, Urituyacu, Chambira, Tigre, Nanay, Napo, Huallaga, and Ucayali. The same as in the snow-crested Andes high above Lake Lauricocha in central Peru, the headstream of the Marañón River rises in the glaciers in what is known as the Nevado de Yarupa. Rushing through waterfalls and gorges in an area of the high jungle called the pongos, the Marañón River flows about 1,000 miles (1,600 km) from west-central to northeast Peru before it combines with the Ucayali River, just below the provincial town of Nauta, to form the mighty Amazon River. The primary tributaries of the Marañón River are--from south to north--the Crisnejas, Chamayo, Urtcubamba, Cenepa, Santiago, Moroña, Pastaza, Huallaga, and Tiger Rivers (Cavero-Egusquiza 1941:49-51).The most distant source of the Amazon was firmly established in 1996, 2001 and 2007 as a glacial stream on a snowcapped 5,597 m (18,363 ft) peak called Nevado Mismi in the Peruvian Andes, roughly 160 km (100 mi) west of Lake Titicaca and 700 km (430 mi) southeast of Lima. The waters from Nevado Mismi flow into the Quebradas Carhuasanta and Apacheta, which flow into the Río Apurímac which is a tributary of the Ucayali which later joins the Marañón to form the Amazon proper.

Formally, though, the union of the Ucayali and the Marañón form the Río Amazonas, which changes its name to Solimões on the triple frontier between Peru, Colombia and Brazil, and later changes its name back to the Amazon only after it meets the Rio Negro near Manaus. After the confluence of Río Apurímac and Ucayali, the river leaves Andean terrain and is instead surrounded by flood plain. From this point to the Marañón, some 1,600 km (990 mi), the forested banks are just out of water, and are inundated long before the river attains its maximum flood-line. The low river banks are interrupted by only a few hills, and the river enters the enormous Amazon Rainforest.

The river systems and flood plains in Brazil, Peru, Ecuador, Colombia and Venezuela whose waters drain into the Solimões and its tributaries are called the "Upper Amazon".

The Amazon Rainforest begins from the eastern edge of the Andes. It is the largest rainforest in the world and is of great ecological significance, as its biomass is capable of absorbing enormous amounts of carbon dioxide. Conservation of the Amazon Rainforest has been a major issue in recent years.

The rainforest is supported by the extremely wet climate of the Amazon basin. The Amazon, and its hundreds of tributaries, flow slowly across the landscape, with an extremely shallow gradient sending them towards the sea: Manaus, 1,600 km (1,000 mi) from the Atlantic, is only 44 m (144 ft) above sea level.

The biodiversity within the rainforest is extraordinary: the region is home to at least 2.5 million insect species, tens of thousands of plants, and some 2,000 birds and mammals. One fifth of all the world's species of birds can be found in the Amazon rainforest.

The diversity of plant species in the Amazon basin is the highest on Earth. Some experts estimate that one square kilometre may contain over 75,000 types of trees and 150,000 species of higher plants.[citation needed] One square kilometre of Amazon rainforest can contain about 90,000 tons of living plants.

The average depth of the river in the height of the rainy season is 40 m (131 ft) and the average width can be nearly 40 km (25 mi)[citation needed]. It starts to rise in November, and increases in volume until June, then falls until the end of October. The rise of the Negro branch is not synchronous; the rainy season does not commence in its valley until February or March. By June it is full, and then it begins to fall with the Amazon. The Madeira rises and falls two months earlier than the Amazon.

The main river (which is between approximately one and six miles wide) is navigable for large ocean steamers to Manaus, 1,500 kilometres (930 mi) upriver from the mouth. Smaller ocean vessels of 3,000 tons and 5.5 metres (18 ft) draft can reach as far as Iquitos, Peru, 3,600 kilometres (2,240 mi) from the sea. Smaller riverboats can reach 780 kilometer (485 mi) higher as far as Achual Point. Beyond that, small boats frequently ascend to the Pongo de Manseriche, just above Achual Point.

The breadth of the Amazon in some places is as much as 6 km (4 mi) to 10 km (6 mi) from one bank to the other[citation needed]. At some points, for long distances, the river divides into two main streams with inland and lateral channels, all connected by a complicated system of natural canals, cutting the low, flat igapo lands, which are never more than 5 m (16 ft) above low river, into many islands.

From the village of Canaria at the great bend of the Amazon to the Negro 1,000 km (600 mi) downstream, only very low land is found, resembling that at the mouth of the river. Vast areas of land in this region are submerged at high water, above which only the upper part of the trees of the sombre forests appear. Near the mouth of the Rio Negro to Serpa, nearly opposite the river Madeira, the banks of the Amazon are low, until approaching Manaus, they rise to become rolling hills. At Óbidos, a bluff 17 m (56 ft) above the river is backed by low hills. The lower Amazon seems to have once been a gulf of the Atlantic Ocean, the waters of which washed the cliffs near Óbidos.

Only about 10% of the water discharged by the Amazon enters the mighty stream downstream of Óbidos, very little of which is from the northern slope of the valley. The drainage area of the Amazon basin above Óbidos is about 5 million km² (2 million mile²), and, below, only about 1 million km² (400,000 mile²), or around 20%, exclusive of the 1.4 million km² (600,000 mile²) of the Tocantins basin.

In the lower reaches of the river, the north bank consists of a series of steep, table-topped hills extending for about 240 km (149 mi) from opposite the mouth of the Xingu as far as Monte Alegre. These hills are cut down to a kind of terrace which lies between them and the river.

Monte Alegre reaches an altitude of several hundred feet. On the south bank, above the Xingu, an almost-unbroken line of low bluffs bordering the flood-plain extends nearly to Santarem, in a series of gentle curves before they bend to the south-west, and, abutting upon the lower Tapajos, merge into the bluffs which form the terrace margin of the Tapajos river valley.

The width of the mouth of the river is usually measured from Cabo do Norte to Punto Patijoca. But this includes the ocean outlet, 60 km (40 mi) wide, of the Para river, which should be deducted, as this stream is only the lower reach of the Tocantins. It also includes the ocean frontage of Marajó, an island lying in the mouth of the Amazon. This means that the Amazon is wider at its mouth than the entire length of the Thames in England.

Following the coast, a little to the north of Cabo do Norte, and for 160 kilometres (99 mi) along its Guiana margin up the Amazon, is a belt of half-submerged islands and shallow sandbanks. Here the tidal phenomenon called the bore, or pororoca, occurs, where the depths are not over 7 metres (23 ft). The tidal bore starts with a roar, constantly increasing, and advances at the rate of from 15 km/h (9 mph) to 25 km/h (16 mph), with a breaking wall of water from 1.5 m (5 ft) to 4 m (13 ft) high. The bore is the reason the Amazon does not have a delta; the ocean rapidly carries away the vast volume of silt carried by the Amazon, making it impossible for a delta to grow. It also has a very large tide sometimes reaching 20 feet (6 m) and has become a popular spot for river surfing in england.

During the wet season the Amazon mouth may grow up to 300 miles long, 500 billion cubic feet of fresh water flows into the Atlantic. That adds up to 5,787,037 cubic feet per second.

During what many archaeologists call the formative period, Amazonian societies were deeply involved in the emergence of South America's highland agrarian systems, and possibly contributed directly to the social and religious fabric constitutive of the Andean civilizational orders.

For 350 years after the European discovery of the mighty Amazon by Vicente Yáñez Pinzón, the Portuguese portion of the basin remained an untended former food gathering and planned agricultural landscape occupied by the Indigenous peoples who survived the arrival of European diseases. There is ample evidence for large-scale, pre-Columbian social formations, including chiefdoms, in many areas of Amazonia (particularly the inter-fluvial regions).

In what is currently Brazil, Ecuador, Bolivia, Colombia, Peru, and Venezuela a number of colonial and religious settlements were established along the banks of primary rivers and tributaries for the purpose of trade, slaving and evangelization among the putatively savage indigenous peoples of the vast rain forest.

The total population of the Brazilian portion of the Amazon basin in 1850 was perhaps 300,000, of whom about two-thirds comprised by Europeans and slaves, the slaves amounting to about 25,000. In Brazil, the principal commercial city, Para (now Belém), had from 10,000 to 12,000 inhabitants, including slaves. The town of Manáos, now Manaus, at the mouth of the Rio Negro, had from 1,000 to 1,500 population. All the remaining villages, as far up as Tabatinga, on the Brazilian frontier of Peru, were relatively small.

On September 6, 1850, the emperor, Dom Pedro II, sanctioned a law authorizing steam navigation on the Amazon, and gave Barão de Mauá (Irineu Evangilista de Sousa) the task of putting it into effect. He organized the "Compania de Navigacao e Commercio do Amazonas" at Rio de Janeiro in 1852; and in the following year it commenced operations with three small steamers, the Monarch, the Marajó and Rio Negro.

At first, navigation was principally confined to the main river; and even in 1857 a modification of the government contract only obliged the company to a monthly service between Pará and Manaus, with steamers of 200 tons cargo capacity, a second line to make six round voyages a year between Manaus and Tabatinga, and a third, two trips a month between Para and Cameta. This was the first step in opening up the vast interior.

The success of the venture called attention to the opportunities for economic exploitation of the Amazon, and a second company soon opened commerce on the Madeira, Purus and Negro; a third established a line between Pará and Manaus; and a fourth found it profitable to navigate some of the smaller streams. In that same period, the Amazonas Company was increasing its fleet. Meanwhile, private individuals were building and running small steam craft of their own on the main river as well as on many of its tributaries.

On July 31 1867 the government of Brazil, constantly pressed by the maritime powers and by the countries encircling the upper Amazon basin, especially Peru, decreed the opening of the Amazon to all flags; but limited this to certain defined points: Tabatinga—on the Amazon; Cameta—on the Tocantins; Santarem—on the Tapajos; Borba—on the Madeira and Manáos—on the Rio Negro. The Brazilian decree took effect on 7 September 1867.

Thanks in part to the mercantile development associated with steam boat navigation, coupled with the internationally driven demand for natural rubber (1880-1920), Manáos (now Manaus), Para (Brazil), and Iquitos, Peru became thriving, cosmopolitan centers of commerce and spectacular—albeit illusory—modern "urban growth". This was particularly the case for Iquitos during its late 19th and early 20th century Rubber Bonanza zenith when this dynamic boom-town was known abroad as the St. Louis of the Amazon.

The first direct foreign trade with Manáos was commenced around 1874. Local trade along the river was carried on by the English successors to the Amazonas Company—the Amazon Steam Navigation Company—as well as numerous small steamboats, belonging to companies and firms engaged in the rubber trade, navigating the Negro, Madeira, Purfis and many other tributaries, such as the Marañón to ports as distant as Nauta, Peru.

By the turn of the 20th century, the principal exports of the Amazon Basin were india-rubber, cacao, Brazil nuts and a few other products of minor importance, such as pelts and exotic forest produce (resins, barks, woven hammocks, prized bird feathers, live animals, etc.) and extracted goods (lumber, gold, etc.).

Four centuries after the European discovery of the Amazon river, the total cultivated area in its basin was probably less than 25 square miles (65 km²), excluding the limited and crudely cultivated areas among the mountains at its extreme headwaters. This situation changed dramatically during the 20th century.
Manaus, the largest city on the Amazon, as seen from a NASA satellite image, surrounded by the muddy Amazon River and the dark Rio Negro.
Manaus, the largest city on the Amazon, as seen from a NASA satellite image, surrounded by the muddy Amazon River and the dark Rio Negro.

Wary of foreign exploitation of the nation's resources, Brazilian governments in the 1940s set out to develop the interior, away from the seaboard where foreigners owned large tracts of land. The original architect of this expansion was President Getúlio Vargas, the demand for rubber from the Allied forces in World War II providing funding for the drive.

The construction of the new capital Brasilia in the interior in 1960 also contributed to the opening up of the Amazon basin. A large scale colonization program saw families from north-eastern Brazil relocated to the forests, encouraged by promises of cheap land. Many settlements grew along the road from Brasilia to Belém, but rainforest soil proved difficult to cultivate.

Still, long-term development plans continued. Roads were cut through the forests, and in 1970, the work on Trans-Amazon highway network began. The network's three pioneering highways were completed within ten years, connecting all the major cities of the Brazilian Amazon interior

While debate as to whether the Amazon or the Nile is the world's longest river has gone on for many years, the historic consensus of geographic authorities has been to regard the Amazon as the second longest river in the world, with the Nile being the longest. However, the Amazon has been measured by different geographers as being anywhere between 6,259 kilometres (3,889 mi) and 6,800 kilometres (4,225 mi) long. The Nile River in Africa is reported to be anywhere from 5,499 kilometres (3,417 mi) to 6,690 kilometres (4,157 mi). The differences in these measurements often result from the use of different definitions.

A recent study by Brazilian scientists claims that the Amazon is actually longer than the Nile. Using Nevado Mismi, which was labeled by the National Geographic Society as the Amazon's source back in 2001, these scientists have made new calculations of the Amazon's length. They now estimate that the Amazon is 65 miles longer than the Nile, and Guido Gelli, director of science at the Brazilian Institute of Geography and Statistics (IBGE), told the Brazilian TV network Globo in June 2007 that it could be considered as a fact that the Amazon was the longest river in the world. However, other geographers have had access to the same data since 2001, and a consensus has yet to emerge to support the claims of these Brazilian scientists.

Regardless of the actual length, the Amazon carries by far the greatest volume of any of Earth's rivers.