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Propeller (marine)
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are specially shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bamboo-copter
The bamboo-copter, also known as the bamboo dragonfly or Chinese top (Chinese ''zhuqingting'' (竹蜻蜓), Japanese ''taketonbo'' ), is a toy helicopter rotor that flies up when its shaft is rapidly spun. This helicopter-like top originated in Jin dynasty China around 320 AD, and was the object of early experiments by English engineer George Cayley, the inventor of modern aeronautics.Leishman, J. Gordon (2006)''Principles of Helicopter Aerodynamics'' Cambridge University Press. pp. 7–9. In China, the earliest known flying toys consisted of feathers at the end of a stick, which was rapidly spun between the hands and released into flight. "While the Chinese top was no more than a toy, it is perhaps the first tangible device of what we may understand as a helicopter." The Jin dynasty Daoist philosopher Ge Hong's (c. 317) book ''Baopuzi'' (抱樸子 "Master Who Embraces Simplicity") mentioned a flying vehicle in what Joseph Needham calls "truly an astonishing passage" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint John, New Brunswick
Saint John is a seaport city of the Atlantic Ocean located on the Bay of Fundy in the province of New Brunswick, Canada. Saint John is the oldest incorporated city in Canada, established by royal charter on May 18, 1785, during the reign of King George III. The port is Canada's third-largest port by tonnage with a cargo base that includes dry and liquid bulk, break bulk, containers, and cruise. The city was the most populous in New Brunswick until the 2016 census, when it was overtaken by Moncton. It is currently the second-largest city in the province, with a population of 69,895 over an area of . French explorer Samuel de Champlain landed at Saint John Harbour on June 24, 1604 (the feast of St. John the Baptist) and is where the Saint John River gets its name although Mi'kmaq and Wolastoqiyik peoples lived in the region for thousands of years prior calling the river Wolastoq. The Saint John area was an important area for trade and defence for Acadia during the French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yarmouth, Nova Scotia
Yarmouth is a town in southwestern Nova Scotia, Canada. A port town, industries include fishing, and tourism. It is the terminus of a ferry service to Bar Harbor, Maine, run by Bay Ferries. History Originally inhabited by the Mi'kmaq, the region was known as "Keespongwitk" meaning "Lands End" due to its position at the tip of the Nova Scotia peninsula. European settlement The region was visited in 1604 by Samuel de Champlain, who named it "Cap-Fourchu", meaning "forked or cloven cape." The first Europeans to make a settlement on these shores were the French Acadians. They set up a small fishing settlement known as "Tebouque" in the mid 1600s and by 1750 the population was 50 people. During the Seven Years' War, New England Planters settled at what is now the town of Yarmouth in 1759; the grantees were from Yarmouth, Massachusetts and they requested that Yarmouth be named after their former home. Yarmouth was founded on June 9, 1761, when a ship carrying three families arrive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Patch
John Patch (1781 – August 27, 1861) was a Nova Scotian fisherman who invented one of the first versions of the screw propeller. Early life Patch was born in Yarmouth, Nova Scotia in 1781. His father Nehemiah was a Yarmouth sea captain who died in a shipwreck at Seal Island, Nova Scotia soon after John Patch's birth. Fishing career Earning a living as a mariner and fishermen, Patch observed the efficiency of small boats propelled by single oar sculling and began to experiment with a propeller based in the motions of a sculling oar. During the winter of 1832-1833 he built a hand-cranked version of a doubled-bladed fan-shaped propeller. He demonstrated his propeller during the summer of 1833 before crowds watching as his small boat moved, seemingly magically, across Yarmouth Harbour. Patch further experimented by attaching his invention to a 25-ton coastal schooner named ''Royal George'' in the Bay of Fundy. The propeller allowed ''Royal George'' to enter Saint John Harbour in a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paddle Wheel
A paddle wheel is a form of waterwheel or impeller in which a number of paddles are set around the periphery of the wheel. It has several uses, of which some are: * Very low-lift water pumping, such as flooding paddy fields at no more than about height above the water source. * To move and mix algae culture in the raceway ponds used for algaculture. * Propulsion of watercraft (as a paddlewheel) * Low head hydro power (as a waterwheel) * Flow sensors * Aerators The paddle wheel is an ancient invention but is still used today in a wide range of industrial and agriculture applications. Ship propulsion Paddle wheels would enable ships to travel without needing wind or oars. They were made obsolete by propellers, which had greater propulsion with lower weight and fuel usage. This was demonstrated by an 1845 tug-of-war Tug of war (also known as tug o' war, tug war, rope war, rope pulling, or tugging war) is a sport that pits two teams against each other in a test of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josef Ressel
Joseph Ludwig Franz Ressel ( cs, Josef Ludvík František Ressel; June 29, 1793 – October 9, 1857) was a forester and inventor of Czech-Austrian descent, who designed one of the first working ship's propellers. Ressel was born in Chrudim, Bohemia then part of the Holy Roman Empire ruled by the Habsburg monarchy, which became part of the Austrian Empire at his death (now the Czech Republic). His father Anton Hermann Ressel was a native German speaker, and his mother Marie Anna Konvičková was a native Czech speaker. He studied at the Linz Gymnasium, Budweis (in today's České Budějovice) artillery school, University of Vienna and the Mariabrunn Forestry Academy at Mariabrunn Monastery then near (now in) Vienna. He worked for the Austrian government as a forester in the more southern parts of the monarchy, including in Motovun, Istria (modern-day Croatia). His work was to secure a supply of quality wood for the Navy.''Josef Ressel. One of the designers of a ship's prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Stevens (inventor, Born 1749)
Col. John Stevens, III (June 26, 1749 – March 6, 1838) was an American lawyer, engineer, and inventor who constructed the first U.S. steam locomotive, first steam-powered ferry, and first U.S. commercial ferry service from his estate in Hoboken. He was influential in the creation of U.S. patent law. Early life Stevens was born June 26, 1749, in New York City, New York. He was the only son of John Stevens Jr. (1715–1792), a prominent state politician who served as a delegate to the Continental Congress, and Elizabeth Alexander (1726–1800). His sister, Mary Stevens (d. 1814), married Robert R. Livingston, the first Chancellor of the State of New York. His maternal grandparents were James Alexander (1691–1756), the Attorney General of New Jersey, and Mary (née Spratt) Provoost Alexander (1693–1760), herself a prominent merchant in New York City. His paternal grandfather, John Stevens, emigrated from London England around 1695, and was married to Mary Campbell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Shorter
Edward Shorter (1767-1836) was an English engineer and inventor of several useful inventions including an early screw propeller. Early life Edward was born in London on 3 December 1767 in the parish of St Sepulchre, Newgate to Robert and Ann Shorter. His father Robert was an impoverished weaver, and while he had been indentured with the Company of Weavers in Basingstoke Street in 1756, and completed his apprenticeship, it is clear that he had insufficient income to support the family. Some time around 1770 the family had to move into the parish workhouse (Chick Lane) to support themselves. Edward’s sister Rachel passed away in 1774 in the Workhouse and Edward was discharged in 1775. Life It is unclear when and through whom Edward learned his trade, however prior to 1798 he had obtained Freedom of the City and was working as a clockmaker in Giltspur Street, London. Together with colleague William Anthony, the renowned watchmaker of Red Lion Street, he succeeded in obtain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isaac Doolittle
Isaac Doolittle (August 3, 1721 – February 13, 1800) was an early American clockmaker, inventor, engineer, manufacturer, militia officer, entrepreneur, printer, politician, and brass, iron, and silver artisan. Doolittle was a watchmaker and clockmaker, known for making and selling at his shop in New Haven, Connecticut one of the first brass wheel hall clocks in America, where he also crafted and sold scientific instruments, and is regarded as "the first native practitioner" of silversmithing in the Connecticut Colony. He was also an engraver and printer of both legal forms and currency, and became the first American to design, manufacture, and sell a printing press in 1769. Somewhat late in life, he became a successful self-educated bell-foundryman, learning the difficult craft of casting large metal bells. Doolittle was an important figure in the religious life of Connecticut as an Episcopal Churchwarden and co-founder of Trinity Church on the Green in New Haven. Cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
