Geology
Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can refer generally to the study of the features of any terrestrial planet. Geology gives insight into the history of the Earth by providing the evidence for plate tectonics, the evolutionary history of life. Geology plays a role in engineering and is a major academic discipline. The majority of data comes from research on solid Earth materials. These typically fall into one of two categories and unconsolidated material, the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three types of rock, igneous and metamorphic. The rock cycle is an important concept in geology which illustrates the relationships between three types of rock, and magma. When a rock crystallizes from melt, it is an igneous rock, the sedimentary rock can be subsequently turned into a metamorphic rock due to heat and pressure and is weathered, eroded and lithified, ultimately becoming a sedimentary rock.
Sedimentary rock may be re-eroded and redeposited, and metamorphic rock may undergo additional metamorphism, all three types of rocks may be re-melted, when this happens, a new magma is formed, from which an igneous rock may once again crystallize. Geologists study unlithified material which typically comes from more recent deposits and these materials are superficial deposits which lie above the bedrock. Because of this, the study of material is often known as Quaternary geology. This includes the study of sediment and soils, including studies in geomorphology and this theory is supported by several types of observations, including seafloor spreading, and the global distribution of mountain terrain and seismicity. This coupling between rigid plates moving on the surface of the Earth and the mantle is called plate tectonics. The development of plate tectonics provided a basis for many observations of the solid Earth. Long linear regions of geologic features could be explained as plate boundaries, mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, were explained as divergent boundaries, where two plates move apart.
Arcs of volcanoes and earthquakes were explained as convergent boundaries, where one plate subducts under another, transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes. Plate tectonics provided a mechanism for Alfred Wegeners theory of continental drift and they provided a driving force for crustal deformation, and a new setting for the observations of structural geology
William Smith (geologist)
William Strata Smith was an English geologist, credited with creating the first nationwide geological map. At the time his map was first published he was overlooked by the community, his relatively humble education. Consequently, his work was plagiarised, financially ruined, he spent time in debtors prison and it was only much in his life that Smith received recognition for his accomplishments, and became known as the Father of English Geology. Smith was born in the village of Churchill, the son of blacksmith John Smith and his father died when Smith was just eight years old, and he was raised by his uncle, called William Smith. Although largely self-educated, Smith was highly intelligent and observant, read widely from an early age, in 1787, he met and found work as an assistant for Edward Webb of Stow-on-the-Wold, Gloucestershire, a surveyor. He was quick to learn, and soon became proficient at the trade, in 1791, he travelled to Somerset to make a valuation survey of the Sutton Court estate, and building on earlier work in the same area by John Strachey.
He stayed in the area for the eight years, working first for Webb and for the Somersetshire Coal Canal Company. Smith worked at one of the older mines, the Mearns Pit at High Littleton, part of the Somerset coalfield. As he observed the rock layers at the pit, he realised that they were arranged in a predictable pattern and that the various strata could always be found in the same relative positions. Additionally, each particular stratum could be identified by the fossils it contained, furthermore, he noticed an easterly dip of the beds of rock—low near the surface, higher after the Triassic rocks. This would earn him the name Strata Smith and he developed methods for the identification of deposits of Fullers earth to the south of Bath. He published his findings with many pictures from his collection, enabling others to investigate their distribution. His collection is good on Jurassic fossils he collected from the Cornbrash, Kimmeridge clay, Oxford clay, Oolitic limestone. They included many types of brachiopods and molluscs characteristic of the seas in which they were deposited.
Some of the names he coined are still used today for this formation, in 1799 Smith produced the first large scale geologic map of the area around Bath, Somerset. Previously, he knew how to draw the vertical extent of the rocks. However, in the Somerset County Agricultural Society, he found a map showing the types of soils and vegetation around Bath, the differing types were coloured. Using this technique, Smith could draw a map from his observations showing the outcrops of the rocks
Chemistry
Chemistry is a branch of physical science that studies the composition, structure and change of matter. Chemistry is sometimes called the science because it bridges other natural sciences, including physics. For the differences between chemistry and physics see comparison of chemistry and physics, the history of chemistry can be traced to alchemy, which had been practiced for several millennia in various parts of the world. The word chemistry comes from alchemy, which referred to a set of practices that encompassed elements of chemistry, philosophy, astronomy, mysticism. An alchemist was called a chemist in popular speech, and the suffix -ry was added to this to describe the art of the chemist as chemistry, the modern word alchemy in turn is derived from the Arabic word al-kīmīā. In origin, the term is borrowed from the Greek χημία or χημεία and this may have Egyptian origins since al-kīmīā is derived from the Greek χημία, which is in turn derived from the word Chemi or Kimi, which is the ancient name of Egypt in Egyptian.
Alternately, al-kīmīā may derive from χημεία, meaning cast together, in retrospect, the definition of chemistry has changed over time, as new discoveries and theories add to the functionality of the science. The term chymistry, in the view of noted scientist Robert Boyle in 1661, in 1837, Jean-Baptiste Dumas considered the word chemistry to refer to the science concerned with the laws and effects of molecular forces. More recently, in 1998, Professor Raymond Chang broadened the definition of chemistry to mean the study of matter, early civilizations, such as the Egyptians Babylonians, Indians amassed practical knowledge concerning the arts of metallurgy and dyes, but didnt develop a systematic theory. Greek atomism dates back to 440 BC, arising in works by such as Democritus and Epicurus. In 50 BC, the Roman philosopher Lucretius expanded upon the theory in his book De rerum natura, unlike modern concepts of science, Greek atomism was purely philosophical in nature, with little concern for empirical observations and no concern for chemical experiments.
Work, particularly the development of distillation, continued in the early Byzantine period with the most famous practitioner being the 4th century Greek-Egyptian Zosimos of Panopolis. He formulated Boyles law, rejected the four elements and proposed a mechanistic alternative of atoms. Before his work, many important discoveries had been made, the Scottish chemist Joseph Black and the Dutchman J. B. English scientist John Dalton proposed the theory of atoms, that all substances are composed of indivisible atoms of matter. Davy discovered nine new elements including the alkali metals by extracting them from their oxides with electric current, british William Prout first proposed ordering all the elements by their atomic weight as all atoms had a weight that was an exact multiple of the atomic weight of hydrogen. The inert gases, called the noble gases were discovered by William Ramsay in collaboration with Lord Rayleigh at the end of the century, thereby filling in the basic structure of the table.
Organic chemistry was developed by Justus von Liebig and others, following Friedrich Wöhlers synthesis of urea which proved that organisms were, in theory
Engineering
The term Engineering is derived from the Latin ingenium, meaning cleverness and ingeniare, meaning to contrive, devise. Engineering has existed since ancient times as humans devised fundamental inventions such as the wedge, wheel, each of these inventions is essentially consistent with the modern definition of engineering. The term engineering is derived from the engineer, which itself dates back to 1390 when an engineer originally referred to a constructor of military engines. In this context, now obsolete, a referred to a military machine. Notable examples of the obsolete usage which have survived to the present day are military engineering corps, the word engine itself is of even older origin, ultimately deriving from the Latin ingenium, meaning innate quality, especially mental power, hence a clever invention. The earliest civil engineer known by name is Imhotep, as one of the officials of the Pharaoh, Djosèr, he probably designed and supervised the construction of the Pyramid of Djoser at Saqqara in Egypt around 2630–2611 BC.
Ancient Greece developed machines in both civilian and military domains, the Antikythera mechanism, the first known mechanical computer, and the mechanical inventions of Archimedes are examples of early mechanical engineering. In the Middle Ages, the trebuchet was developed, the first steam engine was built in 1698 by Thomas Savery. The development of this gave rise to the Industrial Revolution in the coming decades. With the rise of engineering as a profession in the 18th century, similarly, in addition to military and civil engineering, the fields known as the mechanic arts became incorporated into engineering. The inventions of Thomas Newcomen and the Scottish engineer James Watt gave rise to mechanical engineering. The development of specialized machines and machine tools during the revolution led to the rapid growth of mechanical engineering both in its birthplace Britain and abroad. John Smeaton was the first self-proclaimed civil engineer and is regarded as the father of civil engineering.
He was an English civil engineer responsible for the design of bridges, harbours and he was a capable mechanical engineer and an eminent physicist. Smeaton designed the third Eddystone Lighthouse where he pioneered the use of hydraulic lime and his lighthouse remained in use until 1877 and was dismantled and partially rebuilt at Plymouth Hoe where it is known as Smeatons Tower. The United States census of 1850 listed the occupation of engineer for the first time with a count of 2,000, there were fewer than 50 engineering graduates in the U. S. before 1865. In 1870 there were a dozen U. S. mechanical engineering graduates, in 1890 there were 6,000 engineers in civil, mining and electrical. There was no chair of applied mechanism and applied mechanics established at Cambridge until 1875, the theoretical work of James Maxwell and Heinrich Hertz in the late 19th century gave rise to the field of electronics
Carl Spitzweg
Carl Spitzweg was a German romanticist painter, especially of genre subjects. He is considered to be one of the most important artists of the Biedermeier era and he was born in Unterpfaffenhofen, the second of three sons of Franziska and Simon Spitzweg. His father, a merchant, had Carl trained as a pharmacist. He attained his qualification from the University of Munich but, while recovering from an illness, Spitzweg was self-taught as an artist, starting out by copying the works of Flemish masters. He contributed his first work to satiric magazines, upon receiving an inheritance in 1833, he was able to dedicate himself to painting. Later, Spitzweg visited European art centers in Prague, Paris and his paintings and drawings are often humorous genre works. Many of his paintings depict sharply characterized eccentrics, for example The Bookworm and his paintings inspired the musical comedy Das kleine Hofkonzert by Edmund Nick. Playing Piano, an etching by Spitzweg, was found as part of the 2012 Nazi loot discovery, Spitzweg is buried in the Alter Südfriedhof in Munich.
In the late 1930s an art forgery case in Germany involved 54 paintings which had passed off as Spitzweg originals. They had been painted by a Traunstein copyist named Toni who worked from reproductions, Toni signed the works with his own name as after Spitzweg, but fraudsters removed his name and artificially aged the paintings in order to sell them as originals. At the Stuttgart Criminal Court Assizes the conspirators were jailed for up to ten years for the swindle
Stratigraphy
Stratigraphy is a branch of geology which studies rock layers and layering. It is primarily used in the study of sedimentary and layered volcanic rocks, stratigraphy has two related subfields, lithologic stratigraphy or lithostratigraphy, and biologic stratigraphy or biostratigraphy. The first practical application of stratigraphy was by William Smith in the 1790s. Another influential application of stratigraphy in the early 19th century was a study by Georges Cuvier, variation in rock units, most obviously displayed as visible layering, is due to physical contrasts in rock type. This variation can occur vertically as layering, or laterally, and these variations provide a lithostratigraphy or lithologic stratigraphy of the rock unit. Key concepts in stratigraphy involve understanding how certain geometric relationships between rock layers arise and what these geometries imply about their original depositional environment. The basic concept in stratigraphy, called the law of superposition, states, in a stratigraphic sequence.
Chemostratigraphy studies the changes in the proportions of trace elements and isotopes within. Carbon and oxygen isotope ratios vary with time, and researchers can use those to map subtle changes that occurred in the paleoenvironment and this has led to the specialized field of isotopic stratigraphy. Biostratigraphy or paleontologic stratigraphy is based on evidence in the rock layers. Strata from widespread locations containing the fossil fauna and flora are said to be correlatable in time. Biologic stratigraphy was based on William Smiths principle of succession, which predated. It provides strong evidence for the formation and extinction of species, the geologic time scale was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal succession. One important development is the Vail curve, which attempts to define a global historical sea-level curve according to inferences from worldwide stratigraphic patterns, stratigraphy is commonly used to delineate the nature and extent of hydrocarbon-bearing reservoir rocks and traps of petroleum geology.
Chronostratigraphy is the branch of stratigraphy that places an absolute age, a gap or missing strata in the geological record of an area is called a stratigraphic hiatus. This may be the result of a halt in the deposition of sediment, the gap may be due to removal by erosion, in which case it may be called a stratigraphic vacuity. It is called a hiatus because deposition was on hold for a period of time, a physical gap may represent both a period of non-deposition and a period of erosion. A geologic fault may cause the appearance of a hiatus, magnetostratigraphy is a chronostratigraphic technique used to date sedimentary and volcanic sequences
Animal Collective
Animal Collective is an American experimental pop band formed in Baltimore, Maryland in 2003. Its members and founders are Avey Tare, Panda Bear, the bands music is characterized by studio experimentation, vocal harmonies, and an exploration of various genres which include freak folk, noise rock, ambient drone, and psychedelia. Records released under the name Animal Collective may include contributions from any or all of its members, in the case of Dibb, who often takes breaks from recording and performing with the band, his time off does not constitute full leave. The band members met in school and started recording together in various forms of collaboration from a young age, originally a duo comprising Lennox and Portner, the collective was not officially established until all four members came together for the album Here Comes the Indian. Previous collaborations between two or more members were classified under Animal Collectives discography. In 1999, they established the record label Paw Tracks, issuing what is now considered their debut album, Spirit Theyre Gone, Spirit Theyve Vanished, as well as work by other artists.
In 2009, the released their most commercially successful album, Merriweather Post Pavilion. Animal Collective grew out of friendships in Baltimore County. Noah Lennox and Josh Dibb met in the grade at the Waldorf School of Baltimore. After the eighth grade, Lennox went away to a Waldorf high school in Pennsylvania, while Dibb enrolled at The Park School of Baltimore, in 1993, Brian Weitz moved from Philadelphia to Baltimore County and began attending Park as well, becoming friends with Portner. According to Lennox, they attended schools that emphasized creativity, imagination. Weitz and Portner started playing together at the age of fifteen because of their shared love of the band Pavement. Their musical range included cover songs by Pavement and The Cure as well as the songs Poison by Bell Biv DeVoe and we set up a show with four bands—bands that were different formations of us, Portner remembered in an interview with Baltimore City Paper. At that time, the group did not have any contact to the scene in Baltimore and was more about the back porch.
In 1995, Automine self-released their first and only record, the 7-inch-single Paddington Band, around that time, they had their first experiences with psychedelic drugs like LSD and started to improvise while playing music. The four started to discover psychedelic and experimental music like Noggin, as well as krautrock-related bands such as Silver Apples and Can. Meanwhile, Dibb had introduced Lennox to Portner and Weitz, in 1997, Lennox and Dibb both went off to college in the Boston area, while Portner and Weitz attended schools in New York City. Abhorring the new life as a student at NYU, along with Weitz, returned to Maryland every summer to meet Lennox and Dibb, at that time Portner was working on a record, which would eventually become Spirit Theyre Gone, Spirit Theyve Vanished
Sediment
For sediment in beverages, see dregs. For example and silt can be carried in suspension in water and on reaching the sea be deposited by sedimentation. Sediments are most often transported by water, but wind, beach sands and river channel deposits are examples of fluvial transport and deposition, though sediment often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of transport and deposition. Glacial moraine deposits and till are ice-transported sediments, sediment can be classified based on its grain size and/or its composition. Sediment size is measured on a log base 2 scale, called the Phi scale, composition of sediment can be measured in terms of, parent rock lithology mineral composition chemical make-up. This leads to an ambiguity in which clay can be used as both a size-range and a composition, sediment is transported based on the strength of the flow that carries it and its own size, volume and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise and streams carry sediment in their flows.
This sediment can be in a variety of locations within the flow and these relationships are shown in the following table for the Rouse number, which is a ratio of sediment fall velocity to upwards velocity. If the upwards velocity is less than the settling velocity, but still high enough for the sediment to move, it will move along the bed as bed load by rolling, sliding. If the upwards velocity is higher than the velocity, the sediment will be transported high in the flow as wash load. As there are generally a range of different particle sizes in the flow, sediment motion can create self-organized structures such as ripples, antidunes on the river or stream bed. These bedforms are often preserved in rocks and can be used to estimate the direction. Overland flow can erode soil particles and transport them downslope, the erosion associated with overland flow may occur through different methods depending on meteorological and flow conditions. If the initial impact of rain droplets dislodges soil, the phenomenon is called rainsplash erosion, if overland flow is directly responsible for sediment entrainment but does not form gullies, it is called sheet erosion.
If the flow and the substrate permit channelization, gullies may form, glaciers carry a wide range of sediment sizes, and deposit it in moraines. The overall balance between sediment in transport and sediment being deposited on the bed is given by the Exner equation and this expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This can be localized, and simply due to obstacles, examples are scour holes behind boulders, where flow accelerates
Paleontology
Paleontology or palaeontology is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene Epoch. It includes the study of fossils to determine organisms evolution and interactions with each other, paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuviers work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek παλαιός, palaios, i. e. old, ancient, ὄν, on, i. e. being, creature and λόγος, logos, i. e. speech, study. Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of modern humans. It now uses techniques drawn from a range of sciences, including biochemistry, mathematics. The final quarter of the 20th century saw the development of molecular phylogenetics, molecular phylogenetics has been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend.
The simplest definition is the study of ancient life, paleontology is one of the historical sciences, along with archaeology, astronomy, cosmology and history itself. This means that it aims to describe phenomena of the past, hence it has three main elements, description of the phenomena, developing a general theory about the causes of various types of change, and applying those theories to specific facts. Sometimes the smoking gun is discovered by an accident during other research. Paleontology lies on the boundary between biology and geology since paleontology focuses on the record of past life but its source of evidence is fossils. In addition paleontology often uses techniques derived from other sciences, including biology, ecology, techniques developed in engineering have been used to analyse how ancient organisms might have worked, for example how fast Tyrannosaurus could move and how powerful its bite was. As knowledge has increased, paleontology has developed specialised subdivisions, vertebrate paleontology concentrates on fossils of vertebrates, from the earliest fish to the immediate ancestors of modern mammals.
Invertebrate paleontology deals with fossils of such as molluscs, arthropods. Paleobotany focuses on the study of plants, but traditionally includes the study of fossil algae. Palynology, the study of pollen and spores produced by plants and protists. Micropaleontology deals with all microscopic fossil organisms, regardless of the group to which they belong, one example is the development of oxygenic photosynthesis by bacteria, which hugely increased the productivity and diversity of ecosystems. This caused the oxygenation of the atmosphere, these were a prerequisite for the evolution of the most complex eukaryotic cells, from which all multicellular organisms are built
Precious metal
A precious metal is a rare, naturally occurring metallic chemical element of high economic value. Chemically, the precious metals tend to be less reactive than most elements and they are usually ductile and have a high lustre. Historically, precious metals were important as currency but are now regarded mainly as investment, silver and palladium each have an ISO4217 currency code. The best known precious metals are the metals, gold. Although both have industrial uses, they are known for their uses in art, fine jewelry. Other precious metals include the platinum metals, rhodium, osmium, iridium. The demand for metals is driven not only by their practical use but by their role as investments. Historically, precious metals have commanded much higher prices than common industrial metals, a metal is deemed to be precious if it is rare. The discovery of new sources of ore or improvements in mining or refining processes may cause the value of a metal to diminish. The status of a metal can be determined by high demand or market value.
Precious metals in bulk form are known as bullion and are traded on commodity markets, bullion metals may be cast into ingots or minted into coins. The defining attribute of bullion is that it is valued by its mass, the level of purity varies from issue to issue. The purest mass-produced bullion coins are in the Canadian Gold Maple Leaf series, a 100% pure bullion is nearly impossible, as the percentage of impurities diminishes, it becomes progressively more difficult to purify the metal further. Historically, coins had an amount of weight of alloy. The Krugerrand is the first modern example of measuring in pure gold, other bullion coins show neither the purity nor the fine-gold weight on the coin but are recognized and consistent in their composition. Many coins historically showed a denomination in currency, although nominally issued as legal tender, these coins face value as currency is far below that of their value as bullion. For instance, Canada mints a gold coin at a face value of $50 containing one troy ounce of gold—as of May 2011.
Bullion coins minting by national governments gives them some numismatic value in addition to their bullion value, one of the largest bullion coins in the world was the 10, 000-dollar Australian Gold Nugget coin minted in Australia which consists of a full kilogram of 99. 9% pure gold
Natural gas
It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years. The energy that the plants originally obtained from the sun is stored in the form of bonds in the gas. Natural gas is a fuel used as a source of energy for heating, cooking. It is used as fuel for vehicles and as a feedstock in the manufacture of plastics. Natural gas is found in underground rock formations or associated with other hydrocarbon reservoirs in coal beds. Petroleum is another resource and fossil fuel found in proximity to. Most natural gas was created over time by two mechanisms and thermogenic, biogenic gas is created by methanogenic organisms in marshes, bogs and shallow sediments. Deeper in the earth, at temperature and pressure, thermogenic gas is created from buried organic material. In petroleum production gas is burnt as flare gas. The World Bank estimates that over 150 cubic kilometers of gas are flared or vented annually.
Before natural gas can be used as a fuel, Natural gas is often informally referred to simply as gas, especially when compared to other energy sources such as oil or coal. However, it is not to be confused with gasoline, especially in North America, Natural gas was used by the Chinese in about 500 BCE. They discovered a way to transport gas seeping from the ground in crude pipelines of bamboo to where it was used to salt water to extract the salt. The worlds first industrial extraction of gas started at Fredonia, New York. By 2009,66000 km³ had been used out of the total 850000 km³ of estimated remaining reserves of natural gas. An annual increase in usage of 2–3% could result in currently recoverable reserves lasting significantly less, unwanted natural gas was a disposal problem in the active oil fields. If there was not a market for natural gas near the wellhead it was expensive to pipe to the end user. In the 19th century and early 20th century, unwanted gas was burned off at oil fields
American Philosophical Society
Considered the first learned society in the United States, it has played an important role in American cultural and intellectual life for over 270 years. Philosophical Hall, now a museum, is located just east of Independence Hall in Independence National Historical Park and it was founded two years after the University of Pennsylvania, with which it remains closely tied. Since its inception, the society attracted Americas finest minds, the society recruited philosophers from other countries as members, including Alexander von Humboldt, the Marquis de Lafayette, Baron von Steuben, Tadeusz Kościuszko, and Princess Dashkova. By 1746 the society had lapsed into inactivity, Benjamin Franklin was elected the first president. The canal, which had proposed by Thomas Gilpin, Sr. would not become reality until the 1820s. After the American Revolution, the society looked for leadership to Francis Hopkinson, under his influence, the society received land from the government of Pennsylvania, along with a plot of land in Philadelphia where Philosophical Hall now stands.
Illustrious names have continually added to the membership roster, reflecting the societys scope. Charles Darwin, Robert Frost, Louis Pasteur, Elizabeth Cabot Agassiz, John James Audubon, Linus Pauling, Margaret Mead, Maria Mitchell, and Thomas Edison became members of the society. Many members of the Society of the Cincinnati were among the APSs first board members and contributors, today the APS, the APS has published the Transactions of the American Philosophical Society since 1771. Currently five issues each year. The Proceedings have appeared since 1838, they publish the papers delivered at the meetings of the society. The society has published the collected papers of Benjamin Franklin, Joseph Henry, William Penn. Jane Aitken bound some 400 volumes for the society, in 2001, it was opened to the public as The American Philosophical Society Museum, hosting revolving, thematic exhibitions that explore the intersections of history and science. In 1789–90, the Library Company of Philadelphia built its headquarters directly across 5th Street from APS, LCP sold its building in 1884, which was demolished for the expansion of the Drexel & Company Building in 1887.
This building itself was demolished in the mid-1950s, during the creation of Independence National Historical Park, APS built a library on the site in 1958, and recreated the facade of the old LCP building. APS restored the former Farmers & Mechanics Bank building at 425–29 Chestnut Street and it is the site of meetings and most major events hosted or produced by the society. It now contains offices and the Philadelphia Area Center for History of Science, notable American Women, 1607–1950, A Biographical Dictionary
