A railroad tie or crosstie or railway sleeper is a rectangular support for the rails in railroad tracks. Laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. Railroad ties are traditionally made of wood, but pre-stressed concrete is now widely used in Europe and Asia. Steel ties are common on secondary lines in the UK; as of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, azobé and plastic composite. The crosstie spacing of mainline railroad is 19 to 19.5 inches for wood ties or 24 inches for concrete ties. The amount of ties is 3,250 wooden crossties per mile for wood ties or 2640 ties per mile for concrete ties. Rails in the US may be fastened to the tie by a railroad spike; the type of railroad tie used on the predecessors of the first true railway consisted of a pair of stone blocks laid into the ground, with the chairs holding the rails fixed to those blocks.
One advantage of this method of construction was that it allowed horses to tread the middle path without the risk of tripping. In railway use with heavier locomotives, it was found that it was hard to maintain the correct gauge; the stone blocks were in any case unsuitable on soft ground, such as at Chat Moss, where timber ties had to be used. Bi-block ties with a tie rod are somewhat similar. Wooden rail ties were made by hewing with an axe, called axe ties or sawn to achieve at least two flat sides. A variety of softwood and hardwoods timbers are used as ties, oak and karri being popular hardwoods, although difficult to obtain from sustainable sources; some lines use softwoods, including Douglas fir. Softwood is treated, while creosote is the most common preservative for railway ties, preservatives are sometimes used such as pentachlorophenol, chromated copper arsenate and a few other preservatives. Sometimes non-toxic preservatives are used, such as micronized copper. New boron-based wood preserving technology is being employed by major US railroads in a dual treatment process in order to extend the life of wood ties in wet areas.
Some timbers are durable enough. Problems with wooden ties include rot, insect infestation, plate-cutting known as chair shuffle in the UK and spike-pull. For more information on wooden ties the Railway Tie Association maintains a comprehensive website devoted to wood tie research and statistics. Wooden ties can, of course, catch fire. Concrete ties are cheaper and easier to obtain than timber and better able to carry higher axle-weights and sustain higher speeds, their greater weight ensures improved retention of track geometry when installed with continuous-welded rail. Concrete ties have a longer service life and require less maintenance than timber due to their greater weight, which helps them remain in the correct position longer. Concrete ties need to be installed on a well-prepared subgrade with an adequate depth on free-draining ballast to perform well. Concrete ties amplify wheel noise, so wooden ties are used in densely populated areas. On the highest categories of line in the UK, pre-stressed concrete ties are the only ones permitted by Network Rail standards.
Most European railways now use concrete bearers in switches and crossing layouts due to the longer life and lower cost of concrete bearers compared to timber, difficult and expensive to source in sufficient quantities and quality. Steel ties are trough-shaped in section; the ends of the tie are shaped to form a "spade". Housings to accommodate the fastening system are welded to the upper surface of the tie. Steel ties are now in widespread use on secondary or lower-speed lines in the UK where they have been found to be economical to install due their ability to be installed on the existing ballast bed. Steel ties are able to stack in compact bundles unlike timber. Steel ties can be installed onto the existing ballast, unlike concrete ties which require a full depth of new ballast. Steel ties are 100% recyclable and require up to 60% less ballast than concrete ties and up to 45% less than wood ties. Steel ties have suffered from poor design and increased traffic loads over their long service life.
These aged and obsolete designs limited load and speed capacity but can still be found in many locations globally and performing adequately despite decades of service. There are great numbers of steel ties with over 50 years of service and in some cases they can and have been rehabilitated and continue to perform
Kauri gum is a fossilised resin extracted from kauri trees, made into crafts such as jewellery. Kauri forests once covered much of the North Island of New Zealand, before Māori and European settlers caused deforestation, causing several areas to revert to sand dunes and swamps. Afterward, ancient kauri fields continued to provide a source for the gum and the remaining forests. Kauri gum formed when resin from kauri trees leaked out through fractures or cracks in the bark, hardening with the exposure to air. Lumps fell to the ground and became covered with soil and forest litter fossilising. Other lumps formed as branches forked or trees were damaged, which released the resin; the Māori had many uses for the gum. Fresh gum was used as a type of chewing gum. Flammable, the gum was used as a fire-starter, or bound in flax to act as a torch. Burnt and mixed with animal fat, it made a dark pigment for moko tattooing. Kauri gum was crafted into jewellery and small decorative items. Like amber, kauri gum sometimes includes insects and plant material.
Kauri gum was used commercially in varnish, can be considered a type of copal. Kauri gum was found to be good for this, from the mid-1840s was exported to London and America. Tentative exports had begun a few years earlier, for use in marine glue and as fire-kindlers. Since the kauri gum was found to mix more with linseed oil, at lower temperatures, than other resins, by the 1890s, 70 percent of all oil varnishes made in England used kauri gum, it was used to a limited extent in paints during the late 19th century, from 1910 was used extensively in the manufacture of linoleum. From the 1930s, the market for gum dropped as synthetic alternatives were found, but there remained niche uses for the gum in jewellery and specialist high-grade varnish for violins. Kauri gum was Auckland's main export in the second half of the 19th century, sustaining much of the early growth of the city. Between 1850 and 1950, 450,000 tons of gum were exported; the peak in the gum market was 1899, with 11,116 tons exported that year, with a value of £600,000.
The average annual export was with the average price gained £ 63 per ton. The gum varied in color depending on the condition of the original tree, it depended on where the gum had formed and how long it had been buried. Colors ranged through red-brown to black; the size of each lump varied greatly. Swamps tended to yield the small nuggets known as "chips", whereas the hillsides tended to produce larger lumps; the majority were the size of acorns. Kauri gum shares a few characteristics with amber, another fossilised resin found in the Northern Hemisphere, but where amber can be dated as millions of years old, carbon-dating suggests the age of most kauri gum is a few thousand years. Most of the gumfields were in Northland and Auckland, the site of the original kauri forests; the gum was accessible found lying on the ground. Captain Cook reported the presence of resinous lumps on the beach at Mercury Bay, Coromandel, in 1769, although he suspected it came from the mangroves, missionary Samuel Marsden spoke of their presence in Northland in 1819.
By 1850, most of the surface-lying gum had been picked up, people began digging for it. The hillsides yielded shallow-buried gum, but in the swamps and beaches, it was buried much further down. Gum-diggers were men and women who dug for kauri gum, a fossilised resin, in the old kauri fields of New Zealand at the end of the 19th and early 20th centuries; the gum was used for varnish. The term may be a source for the nickname "Digger" given to New Zealand soldiers in World War I. In 1898, a gum-digger described "the life of a gum-digger" as "wretched, one of the last a man would take to."Gum-diggers worked in the old kauri fields, most of which were covered by swamp or scrub, digging for the gum. Much of the population was transient, moving from field to field, they lived in rough huts or tents, it was hard work and not well paid, but it attracted many Maori and European settlers, including women and children. There were many Dalmatians, they were transient workers, rather than settlers, much of their income was sent out of the country, resulting in much resentment from the local workforce.
In 1898, the "Kauri Gum Industry Act" was passed, which reserved gum-grounds for British subjects, requiring all other diggers to be licensed. By 1910, only British subjects could hold gum-digging licences. Gum-digging was the major source of income for settlers in Northland, farmers worked the gumfields in the winter months to subsidise the poor income from their unbroken land. By the 1890s, 20,000 people were engaged in gum-digging. Gum-digging was not restricted to workers in the rural areas. Most gum was dug from the ground using gum-spears and "skelto
Copal is a name given to tree resin the aromatic resins from the copal tree Protium copal used by the cultures of pre-Columbian Mesoamerica as ceremonially burned incense and for other purposes. More the term copal describes resinous substances in an intermediate stage of polymerization and hardening between "gummier" resins and amber; the word copal is derived from the Nahuatl language word copalli, meaning "incense". Although the word itself has been demonstrated to be a loanword to Mayan from Mixe–Zoquean languages. Copal is still used by a number of indigenous peoples of Mexico and Central America as an incense, during sweat lodge ceremonies and sacred mushroom ceremonies, it is available in different forms. The hard, amber-like yellow copal is a less expensive version; the white copal, a hard, sticky substance, is a more expensive version of the same resin. Copal resin from Hymenaea verrucosa is used in incense. By the 18th century, Europeans found it to be a valuable ingredient in making a good wood varnish.
It became used in the manufacture of furniture and carriages. It was sometimes used as a picture varnish. By the late 19th and early 20th century varnish manufacturers in England and America were using it on train carriages swelling its demand. In 1859 Americans consumed 68 percent of the East African trade, controlled through the Sultan of Zanzibar, with Germany receiving 24 percent; the American Civil War and the creation of the Suez Canal led to Germany and Hong Kong taking the majority by the end of that century. East Africa had a higher amount of subfossil copal, found one or two meters below living copal trees, from roots of trees that may have lived thousands of years earlier; this subfossil copal produces a harder varnish. Subfossil copal is well-known from New Zealand, the Dominican Republic and Madagascar, it has inclusions and is sometimes sold as "young amber". Copal can be distinguished from genuine amber by its lighter citrine colour and its surface getting tacky with a drop of acetone or chloroform.
Copal, mineralized is known as copaline. "Copal". Encyclopædia Britannica. 7. 1911. P. 94
Pollen is a fine to coarse powdery substance comprising pollen grains which are male microgametophytes of seed plants, which produce male gametes. Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail; the study of pollen is called palynology and is useful in paleoecology, paleontology and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower. Pollen is used as food and food supplement.
However, because of agricultural practices, it is contaminated by agricultural pesticides. Pollen itself is not the male gamete; each pollen grain contains a generative cell. In flowering plants the vegetative tube cell produces the pollen tube, the generative cell divides to form the two sperm cells. Pollen is produced in the microsporangia in the male cone of a conifer or other gymnosperm or in the anthers of an angiosperm flower. Pollen grains come in a wide variety of shapes and surface markings characteristic of the species. Pollen grains of pines and spruces are winged; the smallest pollen grain, that of the forget-me-not, is around 6 µm in diameter. Wind-borne pollen grains can be as large as about 90–100 µm. In angiosperms, during flower development the anther is composed of a mass of cells that appear undifferentiated, except for a differentiated dermis; as the flower develops, four groups of sporogenous cells form within the anther. The fertile sporogenous cells are surrounded by layers of sterile cells that grow into the wall of the pollen sac.
Some of the cells grow into nutritive cells that supply nutrition for the microspores that form by meiotic division from the sporogenous cells. In a process called microsporogenesis, four haploid microspores are produced from each diploid sporogenous cell, after meiotic division. After the formation of the four microspores, which are contained by callose walls, the development of the pollen grain walls begins; the callose wall is broken down by an enzyme called callase and the freed pollen grains grow in size and develop their characteristic shape and form a resistant outer wall called the exine and an inner wall called the intine. The exine is. Two basic types of microsporogenesis are recognised and successive. In simultaneous microsporogenesis meiotic steps I and II are completed prior to cytokinesis, whereas in successive microsporogenesis cytokinesis follows. While there may be a continuum with intermediate forms, the type of microsporogenesis has systematic significance; the predominant form amongst the monocots is successive.
During microgametogenesis, the unicellular microspores undergo mitosis and develop into mature microgametophytes containing the gametes. In some flowering plants, germination of the pollen grain may begin before it leaves the microsporangium, with the generative cell forming the two sperm cells. Except in the case of some submerged aquatic plants, the mature pollen grain has a double wall; the vegetative and generative cells are surrounded by a thin delicate wall of unaltered cellulose called the endospore or intine, a tough resistant outer cuticularized wall composed of sporopollenin called the exospore or exine. The exine bears spines or warts, or is variously sculptured, the character of the markings is of value for identifying genus, species, or cultivar or individual; the spines may be less than a micron in length referred to as spinulose, or longer than a micron referred to as echinate. Various terms describe the sculpturing such as reticulate, a net like appearance consisting of elements separated from each other by a lumen.
The pollen wall protects the sperm. The pollen grain surface is covered with waxes and proteins, which are held in place by structures called sculpture elements on the surface of the grain; the outer pollen wall, which prevents the pollen grain from shrinking and crushing the genetic material during desiccation, is composed of two layers. These two layers are the tectum and the foot layer, just above the intine; the tectum and foot layer are separated by a region called the columella, composed of strengthening rods. The outer wall is constructed with a resistant biopolymer called sporopollenin. Pollen apertures are regions of the pollen wall that may involve exine thinning or a significant reduction in exine thickness, they allow shrinking and swelling of the grain caused by changes in moisture content. Elongated apertures or furrows in the pollen grain are called sulci. Apertures that are more circular are called pores. Colpi and pores are major features in the identification of classes of pollen.
Pollen may be referre
In botany, an evergreen is a plant that has leaves throughout the year that are always green. This is true if the plant retains its foliage only in warm climates, contrasts with deciduous plants, which lose their foliage during the winter or dry season. There are many different kinds of both trees and shrubs. Evergreens include: most species of conifers, but not all live oak, "ancient" gymnosperms such as cycads most angiosperms from frost-free climates, such as eucalypts and rainforest trees clubmosses and relativesThe Latin binomial term sempervirens, meaning "always green", refers to the evergreen nature of the plant, for instance Cupressus sempervirens Lonicera sempervirens Sequoia sempervirens Leaf persistence in evergreen plants varies from a few months to several decades. Deciduous trees shed their leaves as an adaptation to a cold or dry/wet season. Evergreen trees do lose leaves, but each tree loses its leaves and not all at once. Most tropical rainforest plants are considered to be evergreens, replacing their leaves throughout the year as the leaves age and fall, whereas species growing in seasonally arid climates may be either evergreen or deciduous.
Most warm temperate climate plants are evergreen. In cool temperate climates, fewer plants are evergreen, with a predominance of conifers, as few evergreen broadleaf plants can tolerate severe cold below about −26 °C. In areas where there is a reason for being deciduous, e.g. a cold season or dry season, being evergreen is an adaptation to low nutrient levels. Deciduous trees lose nutrients. In warmer areas, species such as some pines and cypresses grow on disturbed ground. In Rhododendron, a genus with many broadleaf evergreens, several species grow in mature forests but are found on acidic soil where the nutrients are less available to plants. In taiga or boreal forests, it is too cold for the organic matter in the soil to decay so the nutrients in the soil are less available to plants, thus favouring evergreens. In temperate climates, evergreens can reinforce their own survival; these conditions favour the growth of more evergreens and make it more difficult for deciduous plants to persist.
In addition, the shelter provided by existing evergreen plants can make it easier for younger evergreen plants to survive cold and/or drought. Semi-deciduous Helen Ingersoll. "Evergreens". Encyclopedia Americana
Borneo is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, east of Sumatra; the island is politically divided among three countries: Malaysia and Brunei in the north, Indonesia to the south. 73% of the island is Indonesian territory. In the north, the East Malaysian states of Sabah and Sarawak make up about 26% of the island. Additionally, the Malaysian federal territory of Labuan is situated on a small island just off the coast of Borneo; the sovereign state of Brunei, located on the north coast, comprises about 1% of Borneo's land area. A little more than half of the island is in the Northern Hemisphere including Brunei and the Malaysian portion, while the Indonesian portion spans both the Northern and Southern hemispheres. Borneo is home to one of the oldest rainforests in the world; the island is known by many names. Internationally it is known as Borneo, after Brunei, derived from European contact with the kingdom in the 16th century during the Age of Exploration.
The name Brunei derives from the Sanskrit word váruṇa, meaning either "water" or Varuna, the Vedic god of rain. Indonesian natives called it Kalimantan, derived from the Sanskrit word Kalamanthana, meaning "burning weather island". In earlier times, the island was known by other names. In 977, Chinese records began to use the term Bo-ni to refer to Borneo. In 1225, it was mentioned by the Chinese official Chau Ju-Kua; the Javanese manuscript Nagarakretagama, written by Majapahit court poet Mpu Prapanca in 1365, mentioned the island as Nusa Tanjungnagara, which means the island of the Tanjungpura Kingdom. Borneo is surrounded by the South China Sea to the north and northwest, the Sulu Sea to the northeast, the Celebes Sea and the Makassar Strait to the east, the Java Sea and Karimata Strait to the south. To the west of Borneo are the Malay Peninsula and Sumatra. To the south and east are islands of Indonesia: Java and Sulawesi, respectively. To the northeast are the Philippine Islands. With an area of 743,330 square kilometres, it is the third-largest island in the world, is the largest island of Asia.
Its highest point is Mount Kinabalu in Sabah, with an elevation of 4,095 m. Before sea levels rose at the end of the last Ice Age, Borneo was part of the mainland of Asia, with Java and Sumatra, the upland regions of a peninsula that extended east from present day Indochina; the South China Sea and Gulf of Thailand now submerge the former low-lying areas of the peninsula. Deeper waters separating Borneo from neighbouring Sulawesi prevented a land connection to that island, creating the divide known as Wallace's Line between Asian and Australia-New Guinea biological regions; the largest river system is the Kapuas in West Kalimantan, with a length of 1,000 km. Other major rivers include the Mahakam in East Kalimantan, the Barito in South Kalimantan, Rajang in Sarawak and Kinabatangan in Sabah. Borneo has significant cave systems. In Sarawak, the Clearwater Cave has one of the world's longest underground rivers while Deer Cave is home to over three million bats, with guano accumulated to over 100 metres deep.
The Gomantong Caves in Sabah has been dubbed as the "Cockroach Cave" due to the presence of millions of cockroaches inside the cave. The Gunung Mulu National Park in Sarawak and Sangkulirang-Mangkalihat Karst in East Kalimantan which a karst areas contains thousands of smaller caves; the Borneo rainforest is estimated to be around 140 million years old, making it one of the oldest rainforests in the world. It is the centre of the evolution and distribution of many endemic species of plants and animals, the rainforest is one of the few remaining natural habitats for the endangered Bornean orangutan, it is an important refuge for many endemic forest species, including the Borneo elephant, the eastern Sumatran rhinoceros, the Bornean clouded leopard, the hose's palm civet and the dayak fruit bat. Peat swamp forests occupy the entire coastline of Borneo; the soil of the peat swamp are comparatively infertile, while it is known to be the home of various bird species such as the hook-billed bulbul, helmeted hornbill and rhinoceros hornbill.
There are about 15,000 species of flowering plants with 3,000 species of trees, 221 species of terrestrial mammals and 420 species of resident birds in Borneo. There are about 440 freshwater fish species in Borneo; the Borneo river shark is known only from the Kinabatangan River. In 2010, the World Wide Fund for Nature stated that 123 species have been discovered in Borneo since the "Heart of Borneo" agreement was signed in 2007; the WWF has classified the island into seven distinct ecoregions. Most are lowland regions: Borneo lowland rain forests cover most of the island, with an area of 427,500 square kilometres; the Borneo montane rain forests lie in the central highlands of the island, above the 1,000 metres elevation. The Tropical and subtropical grasslands and shrublands on South Kalimantan; the highest elevations of Mount Kinabalu are home to the Kinabalu mountain alpine meadow, an alpine shrubland notable for its numerous endemic species, including many orchids. The island had extensive rainforest cover, but the area w
Georg Eberhard Rumphius
Georg Eberhard Rumphius was a German-born botanist employed by the Dutch East India Company in what is now eastern Indonesia, is best known for his work Herbarium Amboinense produced in the face of severe personal tragedies, including the death of his wife and a daughter in an earthquake, going blind from glaucoma, loss of his library and manuscripts in major fire, losing early copies of his book when the ship carrying it was sunk. In addition to his major contributions to plant systematics, he is remembered for his skills as an ethnographer and his frequent defense of Ambonese peoples against colonialism. Rumphius was the oldest son of August Rumpf, a builder and engineer in Hanau, Anna Elisabeth Keller, sister of Johann Eberhard Keller, governor of the Dutch-speaking Kleve, at that time a district of the Electortel of Brandenburg, he was baptized Georg Eberhard Rumpf in Wölfersheim. He went to the Gymnasium in Hanau. Though born and raised in Germany he spoke and wrote in Dutch from an early age as learned from his mother.
He was recruited by the West India Company, ostensibly to serve the Republic of Venice, but was put on a ship "De Swarte Raef" in 1646 bound for Brazil where the Dutch and Portuguese were fighting over territory. Either through shipwreck or capture he landed in Portugal. Around 1649 he returned to Hanau. A week after his mother's funeral he left Hanau for the last time. Through contacts of his mother's family, he enlisted with the Dutch East Indies Company and left as a midshipman, December 26, 1652, aboard the ship Muyden for the Dutch East Indies, he arrived in Batavia in July 1653, proceeded to the Ambon archipelago in 1654. By 1657 his official title was "engineer and ensign", at which point he requested a transfer to the civilian branch of the company and became second merchant on Hitu island, north of Ambon, he became a merchant in 1662. He started to undertake a study of the flora and fauna of these Spice Islands. In 1666 he was appointed as "secunde" at Ambon directly under Joan Maetsuycker, the governor-general in Batavia, who would give him dispensation from his ordinary duties to complete this study.
Maetsuycker was a patron of science. He would become known as Plinius Indicus; this was the name under which he was made a member by the Academia Naturae Curiosorum in Vienna in 1681. Rumphius is best known for his authorship of Het Amboinsche kruidboek or Herbarium Amboinense, a catalogue of the plants of the island of Amboina, published posthumously in 1741; the work covers 1,200 species, 930 with definite species names, another 140 identified to genus level. The publication of this book was possible because of the governor Johannes Camphuys. Camphuys, an amateur astronomer reviewed the manuscript and ensured a copy was made before the ill-fated manuscript was sent off to Europe for printing. Rumphius provided illustrations and descriptions for nomenclature types for 350 plants, his material contributed to the development of the binomial scientific classification by Linnaeus, his book provided the basis for all future study of the flora of the Moluccas and his work is still referred to today.
Despite the distance, he was in communication with scientists in Europe, was a member of a scientific society in Vienna, sent a collection of Moluccan sea shells to the Medicis in Tuscany. After going blind in 1670 due to glaucoma, Rumphius continued work on his six-volume manuscript with the help of others, his wife and a daughter were killed by a wall collapse during a major earthquake and tsunami on February 17, 1674. On January 11, 1687, with the project nearing completion, a great fire in the town destroyed his library, numerous manuscripts, original illustrations for his Herbarium Amboinense, volumes of the Hortus Malabaricus, works by Jacobus Bontius. Persevering and his helpers first completed the book in 1690, but the ship carrying the manuscript to the Netherlands was attacked and sunk by the French, forcing them to start over from a copy, retained thanks to Camphuys; the Herbarium Amboinense arrived in the Netherlands in 1696. However, "the East India Company decided that it contained so much sensitive information that it would be better not to publish it."
Rumphius died in 1702, so he never saw his work in print. It appeared in 1741, thirty-nine years after Rumphius's death through the work of Johannes Burman who translated it into Latin. Much of the natural history in Oud en Nieuw Oost-Indiën by François Valentijn was by Rumphius and they were close friends; the Herbarium Amboinense as published in 1741 consisted of six large folio volumes. Being blind, Rumphius required the assistance of others to produce it, his wife, was one of the early assistants and she was commemorated in Flos Suzannae a white orchid described by Rumphius. His son Paul August made many of the plant illustrations as the only known portrait of Rumphius. Other assistants included Philips van Eyck, a draughtsman, Daniel Crul, Pieter de Ruyter a soldier trained by Van Eyck, Johan Philip Sipman, Christiaen Gieraerts J. Hoogeboom An English translation, which took seven years to make by E. M. Beekman, was posthumously published in 2011. Among the many species described in the Herbarium was the Upas tree, the toxicity of the t