An auction is a process of buying and selling goods or services by offering them up for bid, taking bids, and buying the item to the highest bidder. The open ascending price auction is arguably the most common form of auction in use today, participants bid openly against one another, with each subsequent bid required to be higher than the previous bid. An auctioneer may announce prices, bidders may call out their bids themselves, in economic theory, an auction may refer to any mechanism or set of trading rules for exchange. The word auction is derived from the Latin augeō which means I increase or I augment, for most of history, auctions have been a relatively uncommon way to negotiate the exchange of goods and commodities. In practice, both haggling and sale by set-price have been more common. Indeed, before the century the few auctions that were held were sporadic. Nonetheless, auctions have a history, having been recorded as early as 500 B. C. According to Herodotus, in Babylon auctions of women for marriage were held annually, the auctions began with the woman the auctioneer considered to be the most beautiful and progressed to the least.
It was considered illegal to allow a daughter to be sold outside of the auction method, during the Roman Empire, following military victory, Roman soldiers would often drive a spear into the ground around which the spoils of war were left, to be auctioned off. Later slaves, often captured as the spoils of war, were auctioned in the forum under the sign of the spear, the Romans used auctions to liquidate the assets of debtors whose property had been confiscated. For example, Marcus Aurelius sold household furniture to pay off debts, One of the most significant historical auctions occurred in the year 193 A. D. when the entire Roman Empire was put on the auction block by the Praetorian Guard. On March 23 The Praetorian Guard first killed emperor Pertinax, offered the empire to the highest bidder, didius Julianus outbid everyone else for the price of 6,250 drachmas per guard, an act that initiated a brief civil war. Didius was beheaded two months when Septimius Severus conquered Rome, from the end of the Roman Empire to the eighteenth century auctions lost favor in Europe, while they had never been widespread in Asia.
In some parts of England during the seventeenth and eighteenth centuries auction by candle began to be used for the sale of goods and leaseholds, other unpredictable processes, such as a footrace, were used in place of the expiration of a candle. This type of auction was first mentioned in 1641 in the records of the House of Lords, the practice rapidly became popular, and in 1660 Samuel Pepyss diary recorded two occasions when the Admiralty sold surplus ships by an inch of candle. The London Gazette began reporting on the auctioning of artwork at the coffeehouses, the first known auction house in the world was Stockholm Auction House, founded by Baron Claes Rålamb in 1674. Other early auction houses that are still in operation include Dorotheum, Bonhams, Phillips de Pury & Company, Freemans, by the end of the 18th century, auctions of art works were commonly held in taverns and coffeehouses. These auctions were held daily, and auction catalogs were printed to announce available items, in some cases these catalogs were elaborate works of art themselves, containing considerable detail about the items being auctioned
The stern is the back or aft-most part of a ship or boat, technically defined as the area built up over the sternpost, extending upwards from the counter rail to the taffrail. The stern lies opposite of the bow, the foremost part of a ship, the term only referred to the aft port section of the ship, but eventually came to refer to the entire back of a vessel. The stern end of a ship is indicated with a navigation light at night. Sterns on European and American wooden sailing ships began with two forms, the square or transom stern and the elliptical, fantail, or merchant stern. This frame is designed to support the beams that make up the stern. In 1817 the British naval architect Sir Robert Seppings first introduced the concept of the round or circular stern, the square stern had been an easy target for enemy cannon, and could not support the weight of heavy stern chase guns. The United States began building the first elliptical stern warship in 1820, USS Brandywine became the first sailing ship to sport such a stern.
In naval architecture, the term transom has two meanings, in this sense, a transom stern is the product of the use of a series of transoms, and hence the two terms have blended. But until a new form of stern appeared in the 19th century, the stern was a floating house—and required just as many timbers, windows. The stern frame provided the structure of the transom stern, and was composed of the sternpost, wing transom. If the stern had transoms above the transom, they would no longer be affixed to the sternpost. The first of these might be called a counter transom, next up was the window sill transom, above that, the larger the vessel, the more numerous and wider the transoms required to support its stern. Stern timbers – These timbers are mounted vertically in a series, each timber typically rests or steps on the transom and stretches out. Those not reaching all the way to the taffrail are called short stern timbers, the two outermost of these timbers, located at the corners of the stern, are called the side-counter timbers or outer stern timbers.
The flat surface of any transom stern may begin either at or above the waterline of the vessel. The geometric line which stretches from the transom to the archboard is called the counter. The visual unpopularity of Seppings circular stern was soon rectified by Sir William Symonds, in this revised stern, a set of straight post timbers stretches from the keel diagonally aft and upward. It rests on the top of the sternpost and runs on either side of the rudder post to a point well above the vessels waterline, the finished stern has a continuous curved edge around the outside and is raked aft
A steamship, often referred to as a steamer, is a vessel, typically ocean-faring and seaworthy, that is propelled by one or more steam engines that typically drive propellers or paddlewheels. The first steamships came into usage during the early 1800s, however. Steamships usually use the designations of PS for paddle steamer or SS for screw steamer. As paddle steamers became less common, SS is assumed by many to stand for steam ship, Ships powered by internal combustion engines use a prefix such as MV for motor vessel, so it is not correct to use SS for most modern vessels. The steamship was preceded by smaller vessels designed for insular transportation, once the technology of steam was mastered at this level, steam engines were mounted on larger, and eventually, ocean-going vessels. Becoming reliable, and propelled by screw rather than paddlewheels, the changed the design of ships for faster. Paddlewheels as the main motive source became standard on these early vessels and it was an effective means of propulsion under ideal conditions but otherwise had serious drawbacks.
Within a few decades of the development of the river and canal steamboat, the first sea-going steamboat was Richard Wrights first steamboat Experiment, an ex-French lugger, she steamed from Leeds to Yarmouth in July 1813. She carried passengers and freight to Paris in 1822 at an speed of 8 knots. The American ship SS Savannah first crossed the Atlantic Ocean, another claimant is the Canadian ship SS Royal William in 1833. The SS Archimedes, built in Britain in 1839 by Francis Pettit Smith, was the worlds first steamship to be driven by a screw propeller. It had considerable influence on development, encouraging the adoption of screw propulsion by the Royal Navy. The key innovation that made ocean-going steamers viable was the change from the paddle-wheel to the screw-propeller as the mechanism of propulsion and these steamships quickly became more popular, because the propellers efficiency was consistent regardless of the depth at which it operated. Being smaller in size and mass and being submerged, it was far less prone to damage.
The development of screw propulsion relied on the technological innovations. Steam engines had to be designed with the power delivered at the bottom of the machinery, a paddle steamers engines drive a shaft that is positioned above the waterline, with the cylinders positioned below the shaft. SS Great Britain used chain drive to power from a paddlers engine to the propeller shaft - the result of a late design change to propeller propulsion. An effective stern tube and associated bearings were required, the stern tube contains the propeller shaft where it passes through the hull structure
A shipwreck is the remains of a ship that has wrecked, which are found either beached on land or sunken to the bottom of a body of water. Shipwrecking may be deliberate or accidental, UNESCO estimates that worldwide over 3 million shipwrecks, some thousands of years old, lie on seabeds. Military wrecks, caused by a skirmish at sea, are studied to find details about the historic event, they reveal much about the battle that occurred. Discoveries of treasure ships, often from the period of European colonisation, some contemporary wrecks, such as the oil tankers Prestige or Erika, are of interest primarily because of their potential harm to the environment. Other contemporary wrecks are scuttled in order to spur growth, such as Adolphus Busch. Well known shipwrecks include the catastrophic Titanic, Lusitania, Empress of Ireland, Andrea Doria, there are thousands of wrecks that were not lost at sea but have been abandoned or sunk. These abandoned, or derelict ships are smaller craft, such as fishing vessels.
They may pose a hazard to navigation and may be removed by port authorities, poor design, improperly stowed cargo and other human errors leading to collisions, bad weather and other causes can lead to accidental sinkings. Intentional reasons for sinking a ship include forming a reef, due to warfare, mutiny or sabotage, as part of target practice. A ship can be used as breakwater structure. The stratification not only creates another challenge for marine archaeology but a challenge to its primary state, stratification includes several different types of sand and/or silt, as well as tumulus and encrustations. These sediments are tightly linked to the type of currents and the type of water, besides this geological phenomenon, wrecks face the damage of marine creatures that create a home out of them, primarily being octopuses and crustaceans. All the above offers great challenges to the marine archaeologist when attempting to bind the pieces of a certain shipwreck together, despite these challenges, if the information retrieved does not appear to be sufficient, or a poor preservation is achieved, authors like J. A.
Parker claim that it is the value of the shipwreck that counts. Often the only parts of ships that remain after a century are those that were buried in silt or sand soon after the sinking. An example of this is the Mary Rose and iron, depending on their thickness, may retain the ships structure for decades. As corrosion takes place, sometimes helped by tides and weather, thick ferrous objects such as cannons, steam boilers or the pressure vessel of a submarine often survive well underwater in spite of corrosion. Propellers, condensers and port holes were made from non-ferrous metals such as brass and phosphor bronze
Mile Rocks Lighthouse
Mile Rocks Lighthouse is a lighthouse on a rock about 2 miles southwest of the Golden Gate Bridge, California. Its now an automated and unnatural looking lighthouse with a flat top, to one side is a smaller, though clearly visible, rock. In 1889, the United States Lighthouse Service placed a bell buoy near the rocks, the strong currents in the area would pull the buoy beneath the surface of the water and set it adrift. The lighthouse was completed in 1906 after considerable difficulty caused by the heavy seas, the rock upon which the lighthouse is built measured only 40 by 30 feet at high water. The base of the tower is a block of concrete protected by steel plating. Steel and concrete in the foundation alone weighed 1,500 tons, the superstructure is of steel, and houses the fog signal apparatus and the quarters for the keepers, with the lantern above. It was on this rock that the SS City of Rio de Janeiro was wrecked shortly before the building of the lighthouse, one hundred and twenty-eight persons, of 209 aboard, lost their lives when the City of Rio de Janeiro sank on February 2,1901.
The original third order Fresnel lens was transferred to the Old Point Loma lighthouse in San Diego, in 1966, all of the tower was removed and only the first story was left, and the light automated. The top of the first story is now a landing pad, list of lighthouses in the United States Historic Light Station Information and Photography, California. United States Coast Guard Historians Office, U. S. Geological Survey Geographic Names Information System, Mile Rock Lighthouse
Fort Point, San Francisco
Fort Point is a masonry seacoast fortification located at the southern side of the Golden Gate at the entrance to San Francisco Bay. This fort was completed just before the American Civil War by the United States Army, the fort is now protected as Fort Point National Historic Site, a United States National Historic Site administered by the National Park Service as a unit of the Golden Gate National Recreation Area. In 1769 Spain occupied the San Francisco area and by 1776 had established the areas first European settlement, with a mission and a presidio. To protect against encroachment by the British and Russians, Spain fortified the high white cliff at the narrowest part of the bays entrance, the Castillo de San Joaquin, built in 1794, was an adobe structure housing nine to thirteen cannons. Mexico won independence from Spain in 1821, gaining control of the region and the fort, following the United States victory in 1848, California was annexed by the U. S. and became a state in 1850. The gold rush of 1849 had caused rapid settlement of the area, military officials soon recommended a series of fortifications to secure San Francisco Bay.
Coastal defenses were built at Alcatraz Island, Fort Mason, the U. S. Army Corps of Engineers began work on Fort Point in 1853. Plans specified that the lowest tier of artillery be as close as possible to water level so cannonballs could ricochet across the surface to hit enemy ships at the water-line. Workers blasted the 90-foot cliff down to 15 feet above sea level, the structure featured seven-foot-thick walls and multi-tiered casemated construction typical of Third System forts. It was sited to defend the maximum amount of harbor area, while there were more than 30 such forts on the East Coast, Fort Point was the only one on the West Coast. In 1854 Inspector General Joseph K. Mansfield declared this point as the key to the whole Pacific Coast. a crew of 200, many unemployed miners, labored for eight years on the fort. In 1861, with war looming, the army mounted the forts first cannon, colonel Albert Sidney Johnston, commander of the Department of the Pacific, prepared Bay Area defenses and ordered in the first troops to the fort.
Kentucky-born Johnston resigned his commission to join the Confederate Army, throughout the Civil War, artillerymen at Fort Point stood guard for an enemy that never came. Troops soon moved out of Fort Point, and it was never again occupied by the army. The fort was important enough to receive protection from the elements. In 1869 a granite seawall was completed, the following year, some of the forts cannon were moved to Battery East on the bluffs nearby, where they were more protected. In 1882 Fort Point was officially named Fort Winfield Scott after the hero from the war against Mexico. The name never caught on and was applied to an artillery post at the Presidio
Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun and the rotation of the Earth. Some shorelines experience a semi-diurnal tide—two nearly equal high and low tides each day, other locations experience a diurnal tide—only one high and low tide each day. A mixed tide—two uneven tides a day, or one high, Tides vary on timescales ranging from hours to years due to a number of factors. To make accurate records, tide gauges at fixed stations measure water level over time, gauges ignore variations caused by waves with periods shorter than minutes. These data are compared to the level usually called mean sea level. Tidal phenomena are not limited to the oceans, but can occur in other systems whenever a gravitational field varies in time. For example, the part of the Earth is affected by tides. Tide changes proceed via the following stages, Sea level rises over several hours, covering the intertidal zone, the water rises to its highest level, reaching high tide.
Sea level falls over several hours, revealing the intertidal zone, the water stops falling, reaching low tide. Oscillating currents produced by tides are known as tidal streams, the moment that the tidal current ceases is called slack water or slack tide. The tide reverses direction and is said to be turning, slack water usually occurs near high water and low water. But there are locations where the moments of slack tide differ significantly from those of high, Tides are commonly semi-diurnal, or diurnal. The two high waters on a day are typically not the same height, these are the higher high water. Similarly, the two low waters each day are the low water and the lower low water. The daily inequality is not consistent and is small when the Moon is over the equator. From the highest level to the lowest, Highest Astronomical Tide – The highest tide which can be predicted to occur, note that meteorological conditions may add extra height to the HAT. Mean High Water Springs – The average of the two high tides on the days of spring tides, mean High Water Neaps – The average of the two high tides on the days of neap tides.
Mean Sea Level – This is the sea level
National Park Service
It was created on August 25,1916, by Congress through the National Park Service Organic Act and is an agency of the United States Department of the Interior. As of 2014, the NPS employs 21,651 employees who oversee 417 units, the National Park Service celebrated its centennial in 2016. National parks and national monuments in the United States were originally individually managed under the auspices of the Department of the Interior, the movement for an independent agency to oversee these federal lands was spearheaded by business magnate and conservationist Stephen Mather, as well as J. Horace McFarland. With the help of journalist Robert Sterling Yard, Mather ran a publicity campaign for the Department of the Interior and they wrote numerous articles that praised the scenic and historic qualities of the parks and their possibilities for educational and recreational benefits. This campaign resulted in the creation of a National Park Service, Mather became the first director of the newly formed NPS.
On March 3,1933, President Herbert Hoover signed the Reorganization Act of 1933, the act would allow the President to reorganize the executive branch of the United States government. It wasnt until that summer when the new President, Franklin D. Roosevelt, President Roosevelt agreed and issued two Executive orders to make it happen. In 1951, Conrad Wirth became director of the National Park Service, the demand for parks after the end of the World War II had left the parks overburdened with demands that could not be met. In 1952, with the support of President Dwight D. Eisenhower, he began Mission 66, New parks were added to preserve unique resources and existing park facilities were upgraded and expanded. In 1966, as the Park Service turned 50 years old, emphasis began to turn from just saving great and wonderful scenery, Director George Hartzog began the process with the creation of the National Lakeshores and National Recreation Areas. Since its inception in 1916, the National Park Service has managed each of the United States national parks, Yellowstone National Park was the first national park in the United States.
In 1872, there was no government to manage it. Yosemite National Park began as a park, the land for the park was donated by the federal government to the state of California in 1864 for perpetual conservation. Yosemite was returned to federal ownership, at first, each national park was managed independently, with varying degrees of success. In Yellowstone, the staff was replaced by the U. S. Army in 1886. Due to the irregularities in managing these national treasures, Stephen Mather petitioned the government to improve the situation. In response, Secretary of the Interior Franklin K. Lane challenged him to lobby for creating a new agency, Mather was successful with the ratification of the National Park Service Organic Act in 1916. Later, the agency was given authority over other protected areas, the National Park System includes all properties managed by the National Park Service
A tug is a boat or ship that maneuvers vessels by pushing or towing them. Tugboats are powerful for their size and strongly built, and some are ocean-going, some tugboats serve as icebreakers or salvage boats. Early tugboats had steam engines, but today most have diesel engines, many tugboats have firefighting monitors, allowing them to assist in firefighting, especially in harbors. Seagoing tugs fall into four categories, The standard seagoing tug with model bow that tows its payload on a hawser. The notch tug which can be secured in a notch at the stern of a specially designed barge and this configuration is dangerous to use with a barge which is in ballast or in a head- or following sea. Therefore, notch tugs are usually built with a towing winch and these units stay combined under virtually any sea conditions and the tugs usually have poor sea-keeping designs for navigation without their barges attached. Vessels in this category are considered to be ships rather than tugboats. These vessels must show navigation lights compliant with those required of ships rather than required of tugboats.
Articulated tug and barge units utilize mechanical means to connect to their barges, the tug slips into a notch in the stern and is attached by a hinged connection. ATBs generally utilize Intercon and Bludworth connecting systems, aTBs are generally staffed as a large tugboat, with between seven and nine crew members. The typical American ATB operating on the east coast customarily displays navigational lights of a towing vessel pushing ahead, compared to seagoing tugboats, harbour tugboats are generally smaller and their width-to-length ratio is often higher, due to the need for a lower draught. In smaller harbours these are termed lunch bucket boats, because they are only manned when needed and only at a minimum. The number of tugboats in a harbour varies with the harbour infrastructure, things to take into consideration includes ships with/without bow thrusters and forces like wind and waves and types of ship. River tugs are referred to as towboats or pushboats and their hull designs would make open ocean operation dangerous.
River tugs usually do not have any significant hawser or winch and their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees. Tugboat engines typically produce 500 to 2,500 kW, for safety, tugboats engines often feature two of each critical part for redundancy. A tugboats power is stated by its engines horsepower and its overall bollard pull. The largest commercial harbour tugboats in the 2000s-2010s, used for towing container ships or similar, had around 60-65 tons of bollard pull, Tugboats are highly maneuverable, and various propulsion systems have been developed to increase maneuverability and increase safety
It has a population of around 4.5 million, of whom nearly a quarter live in the metropolitan area of the capital and largest city, San José. Costa Rica was sparsely inhabited by people before coming under Spanish rule in the 16th century. Since then, Costa Rica has remained among the most stable, following a brief civil war, it permanently abolished its army in 1949, becoming one of only a few sovereign nations without a standing army. Costa Rica is a member of the Organisation Internationale de la Francophonie. The country has consistently performed favourably in the Human Development Index, placing 69th in the world as of 2015 and its rapidly developing economy, once heavily dependent on agriculture, has diversified to include sectors such as finance and ecotourism. Costa Rica is known for its environmental policies, being the only country to meet all five UNDP criteria established to measure environmental sustainability. Costa Rica officially plans to become a country by 2021. In 2012, it became the first country in the Americas to ban recreational hunting, historians have classified the indigenous people of Costa Rica as belonging to the Intermediate Area, where the peripheries of the Mesoamerican and Andean native cultures overlapped.
More recently, pre-Columbian Costa Rica has described as part of the Isthmo-Colombian Area. The oldest evidence of occupation in Costa Rica is associated with the arrival of various groups of hunter-gatherers about 10,000 to 7,000 years BCE in the Turrialba Valley. The presence of Clovis culture type spearheads and arrows from South America opens the possibility that, in this area, agriculture became evident in the populations that lived in Costa Rica about 5,000 years ago. They mainly grew tubers and roots, for the first and second millennia BCE there were already settled farming communities. These were small and scattered, although the transition from hunting and gathering to agriculture as the livelihood in the territory is still unknown. The earliest use of pottery appears around 2,000 to 3,000 BCE, shards of pots, cylindrical vases, platters and other forms of vases decorated with grooves and some modelled after animals have been found. The impact of indigenous peoples on modern Costa Rican culture has been small compared to other nations.
Costa Rica was described as the poorest and most miserable Spanish colony in all America by a Spanish governor in 1719, for all these reasons, Costa Rica was, by and large and overlooked by the Spanish Crown and left to develop on its own. Costa Rica became a democracy with no oppressed mestizo or indigenous class. It was not long before Spanish settlers turned to the hills, where they found rich volcanic soil, like the rest of Central America, Costa Rica never fought for independence from Spain
Golden Gate National Recreation Area
The Golden Gate National Recreation Area is a U. S. National Recreation Area protecting 80,002 acres of ecologically and historically significant landscapes surrounding the San Francisco Bay Area. Much of the park is land used by the United States Army. GGNRA is managed by the National Park Service and is one of the most visited units of the National Park system in the United States, with more than 15 million visitors a year. It is one of the largest urban parks in the world, the park is not one continuous locale, but rather a collection of areas that stretch from southern San Mateo County to northern Marin County, and includes several areas of San Francisco. The park is as diverse as it is expansive, it contains famous tourist attractions such as Muir Woods National Monument, the park was created thanks to the cooperative legislative efforts of cosponsors Congressman William S. Mailliard and Congressman Phillip Burton. In 1972, President Richard Nixon signed into law An Act to Establish the Golden Gate National Recreation Area, the bill allocated $120 million for land acquisition and development.
The National Park Service first purchased Alcatraz and Fort Mason from the U. S. Army, the Nature Conservancy transferred the land to the GGNRA. These properties formed the basis for the park. Throughout the next 30 years, the National Park service acquired land and historic sites from the U. S. Army, private landowners and corporations, incorporating them into the GGNRA. Many decommissioned Army bases and fortifications were incorporated into the park, including Fort Funston, four Nike missile sites, The Presidio, the latest acquisition by the National Park Service is Mori Point, a small parcel of land on the Pacifica coast. In 1988, UNESCO designated the GGNRA and 12 adjacent protected areas the Golden Gate Biosphere Reserve, the property, located south of Pacifica and surrounding the communities of Moss Beach and Montara, is home to many diverse plant and animal species. The bill passed in the Senate, but did not pass the House of Representatives, Fort Baker - former Army post located on the northern side of the Golden Gate Headlands Center for the Arts - an artist residency program set in renovated military buildings in the Marin Headlands.
Nike Missile Site SF-88 - a decommissioned Army surface-to-air missile site located near Fort Barry, located at the southwestern corner of the Presidio Battery Chamberlin - one of the last remaining coastal defense disappearing guns on the U. S. Trails lead across the ridge and to Sharp Park beach, the site includes recently restored wetlands and a pond, protecting endangered San Francisco garter snake and red-legged frog habitat. Rancho Corral de Tierra - the GGNRAs newest park, Golden Gate National Recreation Area Scenery Video, a video showing the scenery observed from the GGNRA, including footage from Lands End
A paddle steamer is a steamship or riverboat powered by a steam engine that drives paddle wheels to propel the craft through the water. In antiquity, paddle wheelers followed the development of poles and sails, modern paddle wheelers may be powered by diesel engines. The paddle wheel is a steel framework wheel. The outer edge of the wheel is fitted with numerous, regularly-spaced paddle blades, the bottom quarter or so of the wheel travels underwater. An engine rotates the wheel in the water to produce thrust. More advanced paddle wheel designs feature feathering methods that keep each paddle blade closer to vertical while in the water to increase efficiency, the upper part of a paddle wheel is normally enclosed in a paddlebox to minimise splashing. There are two ways to mount paddle wheels on a ship, either a single wheel on the rear, known as a sternwheeler, or a paddle wheel on each side. Both sternwheelers and sidewheelers were used as riverboats in the United States, some still operate for tourists, for example on the Mississippi River.
Sidewheelers are used as riverboats and as coastal craft and this extra maneuverability makes sidewheelers popular on the narrower, winding rivers of the Murray-Darling system in Australia, where a number still operate. European sidewheelers, such as the PS Waverley, connect the wheels with solid drive shafts that limit maneuverability, some were built with paddle clutches that disengage one or both paddles so they can turn independently. However, wisdom gained from experience with sidewheelers deemed that they be operated with clutches out. Crews noticed that as ships approached the dock, passengers moved to the side of the ready to disembark. The shift in weight, added to independent movements of the paddles, could lead to imbalance, in a simple paddle wheel, where the paddles are fixed around the periphery, power is lost due to churning of the water as the paddles enter and leave the water surface. Ideally, the paddles should remain vertical while under water and this ideal can be approximated by use of levers and linkages connected to a fixed eccentric.
The eccentric is fixed slightly forward of the wheel centre. It is coupled to each paddle via a rod and lever, the geometry is designed such that the paddles are kept almost vertical for the short duration that they are in the water. One of the drawings of the Anonymous Author of the Hussite Wars shows a boat with a pair of paddle-wheels at each end turned by men operating compound cranks. In 1704, the French physicist Denis Papin constructed the first ship powered by his steam engine and this made him the first to construct a steam-powered boat