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Screw Propeller
A propeller (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 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 (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from stern sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strabo
Strabo''Strabo'' (meaning "squinty", as in strabismus) was a term employed by the Romans for anyone whose eyes were distorted or deformed. The father of Pompey was called "Gnaeus Pompeius Strabo, Pompeius Strabo". A native of Sicily so clear-sighted that he could see things at great distance as if they were nearby was also called "Strabo". (; ''Strábōn''; 64 or 63 BC) was an ancient Greece, ancient Greek geographer who lived in Anatolia, Asia Minor during the transitional period of the Roman Republic into the Roman Empire. He is best known for his work ''Geographica'', which presented a descriptive history of people and places from different regions of the world known during his lifetime. Additionally, Strabo authored historical works, but only fragments and quotations of these survive in the writings of other authors. Early life Strabo was born to an affluent family from Amasya, Amaseia in Kingdom of Pontus, Pontus in around 64BC. His family had been involved in politics s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saybrook, Connecticut
Deep River is a New England town, town in Middlesex County, Connecticut, Middlesex County, Connecticut, United States. The town is part of the Lower Connecticut River Valley Planning Region, Connecticut, Lower Connecticut River Valley Planning Region. The population was 4,415 at the 2020 United States census, 2020 census. The Deep River Center, Connecticut, town center is designated by the U.S. Census Bureau as a census-designated place (CDP). Deep River is part of what the locals call the "Tri-town Area", made up of the towns of Deep River, Chester, and Essex. Geography According to the United States Census Bureau, the town has a total area of , of which is land and (4.30%) is water. The CDP has a total area of , of which 4.38% is water. Principal communities *Deep River Center, Connecticut, Deep River Center *Winthrop History Saybrook Colony formally joined Connecticut in 1644. The portion of the original colony east of the Connecticut River was set off as a separate town in ... [...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 Grandfather clock, 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 (publishing), 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 Bellfounding, 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 Church (United States), Episcop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Bushnell (inventor)
David Bushnell (August 30, 1740 – 1824) was an American inventor, Patriot (American Revolution), patriot, teacher, and a medical doctor. Bushnell invented the first submarine to be used in battle, ''Turtle (submersible), Turtle'', as well as a floating mine triggered by contact. He was a veteran of the American Revolutionary War, Revolutionary War. Early life David Bushnell was born in a secluded part of Saybrook, Connecticut on 30 August 1740 and baptized in 1753 into a farming family in what is now Westbrook, Connecticut where his parents Nehemiah Bushnell and Sarah (Susan) Ingham Bushnell owned a farm. He was the first of five children born. Following the death of his father circa 1769, he sold his half interest in the family Westbrook farm to his brother Ezra and entered Yale University, Yale College in 1771 at the relatively old age of 31. The ''Turtle'' submarine Bushnell is credited with creating the first submarine ever used in combat, while studying at Yale in 177 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Haven, Connecticut
New Haven is a city of the U.S. state of Connecticut. It is located on New Haven Harbor on the northern shore of Long Island Sound. With a population of 135,081 as determined by the 2020 United States census, 2020 U.S. census, New Haven is List of municipalities in Connecticut, the third largest city in Connecticut after Bridgeport, Connecticut, Bridgeport and Stamford, Connecticut, Stamford, the largest city in the South Central Connecticut Planning Region, Connecticut, South Central Connecticut Planning Region, and the principal municipality of Greater New Haven metropolitan area, which had a total population of 864,835 in 2020. New Haven was one of the first Planned community, planned cities in the U.S. A year after its founding by English Puritans in 1638, eight streets were laid out in a four-by-four Grid plan, grid, creating the "Nine Square Plan". The central common block is New Haven Green, the New Haven Green, a square at the center of Downtown New Haven. The Green is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Watt
James Watt (; 30 January 1736 (19 January 1736 OS) – 25 August 1819) was a Scottish inventor, mechanical engineer, and chemist who improved on Thomas Newcomen's 1712 Newcomen steam engine with his Watt steam engine in 1776, which was fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world. While working as an instrument maker at the University of Glasgow, Watt became interested in the technology of steam engines. At the time engineers such as John Smeaton were aware of the inefficiencies of Newcomen's engine and aimed to improve it. Watt's insight was to realise that contemporary engine designs wasted a great deal of energy by repeatedly cooling and reheating the cylinder. Watt introduced a design enhancement, the separate condenser, which avoided this waste of energy and radically improved the power, efficiency, and cost-effectiveness of steam engines. Eventually, he adapted his engine to produce rot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Hooke
Robert Hooke (; 18 July 16353 March 1703) was an English polymath who was active as a physicist ("natural philosopher"), astronomer, geologist, meteorologist, and architect. He is credited as one of the first scientists to investigate living things at microscopic scale in 1665, using a compound microscope that he designed. Hooke was an impoverished scientific inquirer in young adulthood who went on to become one of the most important scientists of his time. After the Great Fire of London in 1666, Hooke (as a surveyor and architect) attained wealth and esteem by performing more than half of the Boundary (real estate), property line surveys and assisting with the city's rapid reconstruction. Often vilified by writers in the centuries after his death, his reputation was restored at the end of the twentieth century and he has been called "England's Leonardo da Vinci, Leonardo [da Vinci]". Hooke was a Fellow of the Royal Society and from 1662, he was its first Curator of Experimen ... [...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".J ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptians
Egyptians (, ; , ; ) are an ethnic group native to the Nile, Nile Valley in Egypt. Egyptian identity is closely tied to Geography of Egypt, geography. The population is concentrated in the Nile Valley, a small strip of cultivable land stretching from the Cataracts of the Nile, First Cataract to the Mediterranean Basin, Mediterranean and enclosed by desert both to the Eastern Desert, east and to the Western Desert (North Africa), west. This unique geography has been the basis of the DNA history of Egypt, development of Egyptian society since Ancient Egypt, antiquity. The daily language of the Egyptians is a continuum of the local variety of Arabic, varieties of Arabic; the most famous dialect is known as Egyptian Arabic or ''Masri''. Additionally, a sizable minority of Egyptians living in Upper Egypt speak Sa'idi Arabic. Egyptians are predominantly adherents of Sunni Islam with a small Shia minority and a significant proportion who follow native Sufi tariqah, orders.Hoffman, Val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes' Screw
The Archimedes' screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest documented hydraulic machines. It was so-named after the Greek mathematician Archimedes who first described it around 234 BC, although the device had been developed in Egypt earlier in the century. It is a reversible hydraulic machine that can be operated both as a pump or a power generator. As a machine used for lifting water from a low-lying body of water into irrigation ditches, water is lifted by turning a screw-shaped surface inside a pipe. In the modern world, Archimedes screw pumps are widely used in wastewater treatment plants and for dewatering low-lying regions. Run in reverse, Archimedes screw turbines act as a new form of small hydroelectric powerplant that can be applied even in low head sites. Such generators operate in a wide range of flows (0.01 m^3/s to 14.5 m^3/s) and heads (0.1 m to 10 m), including low heads and moderate flow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrigation
Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been developed by many cultures around the world. Irrigation helps to grow crops, maintain landscapes, and revegetation, revegetate disturbed soils in dry areas and during times of below-average rainfall. In addition to these uses, irrigation is also employed to protect crops from frost, suppress weed growth in grain fields, and prevent soil consolidation. It is also used to cool livestock, reduce dust, dispose of sewage, and support mining operations. Drainage, which involves the removal of surface and sub-surface water from a given location, is often studied in conjunction with irrigation. There are several methods of irrigation that differ in how water is supplied to plants. Surface irrigation, also known as gravity irrigation, is the olde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
