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George B. Grant
George Barnard Grant (December 21, 1849 – August 16, 1917) was an American mechanical engineer, inventor, entrepreneur and botanist. He is notable for having made important contributions to 19th-century mechanical calculators, for pioneering new techniques in gear making, and for starting several successful companies. Grant came to be known as "the Father of the American Gear Cutting Industry". Several of his businesses continued to operate many years after his death. Personal life Grant was born in Gardiner, Maine, to Peter Grant, a farmer, and Vesta (Capen) Grant. Both his parents were descended from families that originally came to New England in the 1630s. He prepared for college at Bridgton Academy and then started at the Chandler Scientific School at Dartmouth College, where he studied for three terms. In 1869 Grant transferred to the Lawrence Scientific School at Harvard University, graduating with a B.S. degree in 1873. After graduation from Harvard, Grant lived in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botanist
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek word (''botanē'') meaning "pasture", "herbs" "grass", or " fodder"; is in turn derived from (), "to feed" or "to graze". Traditionally, botany has also included the study of fungi and algae by mycologists and phycologists respectively, with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress. Nowadays, botanists (in the strict sense) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants (including approximately 369,000 species of flowering plants), and approximately 20,000 are bryophytes. Botany originated in prehistory as herbalism with the efforts of early humans to identify – and later cultivate – edible, med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centennial Exposition
The Centennial International Exhibition of 1876, the first official World's Fair to be held in the United States, was held in Philadelphia, Pennsylvania, from May 10 to November 10, 1876, to celebrate the 100th anniversary of the signing of the Declaration of Independence in Philadelphia. Officially named the International Exhibition of Arts, Manufactures, and Products of the Soil and Mine, it was held in Fairmount Park along the Schuylkill River on fairgrounds designed by Herman J. Schwarzmann. Nearly 10 million visitors attended the exposition, and 37 countries participated in it. Precursor The Great Central Fair on Logan Square in Philadelphia, Pennsylvania, in 1864 (also known as the Great Sanitary Fair), was one of the many United States Sanitary Commission's Sanitary Fairs held during the Civil War. They provided a creative and communal means for ordinary citizens to promote the welfare of Union soldiers and dedicate themselves to the survival of the nation, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1917 Deaths
Events Below, the events of World War I have the "WWI" prefix. January * January 9 – WWI – Battle of Rafa: The last substantial Ottoman Army garrison on the Sinai Peninsula is captured by the Egyptian Expeditionary Force's Desert Column. * January 10 – Imperial Trans-Antarctic Expedition: Seven survivors of the Ross Sea party were rescued after being stranded for several months. * January 11 – Unknown saboteurs set off the Kingsland Explosion at Kingsland (modern-day Lyndhurst, New Jersey), one of the events leading to United States involvement in WWI. * January 16 – The Danish West Indies is sold to the United States for $25 million. * January 22 – WWI: United States President Woodrow Wilson calls for "peace without victory" in Germany. * January 25 ** WWI: British armed merchantman is sunk by mines off Lough Swilly (Ireland), with the loss of 354 of the 475 aboard. ** An anti-prostitution drive in San Francisco occurs, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1849 Births
Events January–March * January 1 – France begins issue of the Ceres series, the nation's first postage stamps. * January 5 – Hungarian Revolution of 1848: The Austrian army, led by Alfred I, Prince of Windisch-Grätz, enters in the Hungarian capitals, Buda and Pest. The Hungarian government and parliament flee to Debrecen. * January 8 – Hungarian Revolution of 1848: Romanian armed groups massacre 600 unarmed Hungarian civilians, at Nagyenyed.Hungarian HistoryJanuary 8, 1849 And the Genocide of the Hungarians of Nagyenyed/ref> * January 13 ** Second Anglo-Sikh War – Battle of Tooele: British forces retreat from the Sikhs. ** The Colony of Vancouver Island is established. * January 21 ** General elections are held in the Papal States. ** Hungarian Revolution of 1848: Battle of Nagyszeben – The Hungarian army in Transylvania, led by Josef Bem, is defeated by the Austrians, led by Anton Puchner. * January 23 – Elizabeth Blackwell is awarded her M.D. by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Inventors
American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, people who self-identify their ancestry as "American" ** American English, the set of varieties of the English language native to the United States ** Native Americans in the United States, indigenous peoples of the United States * American, something of, from, or related to the Americas, also known as "America" ** Indigenous peoples of the Americas * American (word), for analysis and history of the meanings in various contexts Organizations * American Airlines, U.S.-based airline headquartered in Fort Worth, Texas * American Athletic Conference, an American college athletic conference * American Recordings (record label), a record label previously known as Def American * American University, in Washington, D.C. Sports teams Soccer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Involute Gear
The involute gear profile is the most commonly used system for gearing today, with cycloid gearing still used for some specialties such as clocks. In an involute gear, the profiles of the teeth are ''involutes of a circle.'' The involute of a circle is the spiraling curve traced by the end of an imaginary taut string unwinding itself from that stationary circle called the base circle, or (equivalently) a triangle wave projected on the circumference of a circle. The involute gear profile was a fundamental advance in machine design, since unlike with other gear systems, the tooth profile of an involute gear depends only on the number of teeth on the gear, pressure angle, and pitch. That is, a gear's profile does not depend on the gear it mates with. Thus, n and m tooth involute spur gear Spur gears or straight-cut gears are the simplest type of gear. They consist of a cylinder or disk with teeth projecting radially. Viewing the gear at 90 degrees from the shaft length (side on) t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloidal Gear
The cycloidal gear profile is a form of toothed gear used in mechanical clocks, rather than the involute gear form used for most other gears. The gear tooth profile is based on the epicycloid and hypocycloid curves, which are the curves generated by a circle rolling around the outside and inside of another circle, respectively. When two toothed gears mesh, an imaginary circle, the ''pitch circle'', can be drawn around the centre of either gear through the point where their teeth make contact. The curves of the teeth outside the pitch circle are known as the ''addenda'', and the curves of the tooth spaces inside the pitch circle are known as the ''dedenda''. An addendum of one gear rests inside a dedendum of the other gear. In the cycloidal gears, the addenda of the wheel teeth are convex epi-cycloidal and the dedenda of the pinion are concave hypocycloidal curves generated by the same generating circle. This ensures that the motion of one gear is transferred to the other at l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Institution
The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded on August 10, 1846, it operates as a trust instrumentality and is not formally a part of any of the three branches of the federal government. The institution is named after its founding donor, British scientist James Smithson. It was originally organized as the United States National Museum, but that name ceased to exist administratively in 1967. Called "the nation's attic" for its eclectic holdings of 154 million items, the institution's 19 museums, 21 libraries, nine research centers, and zoo include historical and architectural landmarks, mostly located in the District of Columbia. Additional facilities are located in Maryland, New York, and Virginia. More than 200 institutions and museums in 45 states,States without Smithsonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Difference Engine
A difference engine is an automatic mechanical calculator designed to tabulate polynomial functions. It was designed in the 1820s, and was first created by Charles Babbage. The name, the difference engine, is derived from the method of divided differences, a way to interpolate or tabulate functions by using a small set of polynomial co-efficients. Some of the most common mathematical functions used in engineering, science and navigation, were, and still are computable with the use of the difference engine's capability of computing logarithmic and trigonometric functions, which can be approximated by polynomials, so a difference engine can compute many useful tables of numbers. History The notion of a mechanical calculator for mathematical functions can be traced back to the Antikythera mechanism of the 2nd century BC, while early modern examples are attributed to Pascal and Leibniz in the 17th century. In 1784 J. H. Müller, an engineer in the Hessian army, devised a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philadelphia
Philadelphia, often called Philly, is the List of municipalities in Pennsylvania#Municipalities, largest city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, the List of United States cities by population, sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic (United States), Mid-Atlantic regions after New York City. Act of Consolidation, 1854, Since 1854, the city has been coextensive with Philadelphia County, Pennsylvania, Philadelphia County, the List of counties in Pennsylvania, most populous county in Pennsylvania and the urban core of the Delaware Valley, the Metropolitan statistical area, nation's seventh-largest and one of List of largest cities, world's largest metropolitan regions, with 6.245 million residents . The city's population at the 2020 United States census, 2020 census was 1,603,797, and over 56 million people live within of Philadelphia. Philadelphia was founded in 1682 by William Penn, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Georg Scheutz
Pehr (Per) Georg Scheutz (23 September 1785 – 22 May 1873) was a Swedish lawyer, translator, and inventor, who is now best known for his pioneering work in computer technology. Life Scheutz studied law at Lund University, graduating in 1805. He then worked as a legal expert and translator (he translated several works of William Shakespeare and Sir Walter Scott) before turning predominantly to liberal politics and mechanical engineering. He is most known for his inventions; the best known of these is the Scheutzian calculation engine, invented in 1837 and finalized in 1843. This machine, which he constructed with his son Edvard Scheutz, was based on Charles Babbage's difference engine. In 1851 they obtained funds from government to build an improved model, which was created in 1853 (was roughly the size of a piano), and subsequently demonstrated at the World's Fair in Paris, 1855. The machine was then sold in 1856 to the Dudley Observatory in Albany, New York. In 1857 British ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators were comparable in size to small desktop computers and have been rendered obsolete by the advent of the electronic calculator and the digital computer. Surviving notes from Wilhelm Schickard in 1623 reveal that he designed and had built the earliest of the modern attempts at mechanizing calculation. His machine was composed of two sets of technologies: first an abacus made of Napier's bones, to simplify multiplications and divisions first described six years earlier in 1617, and for the mechanical part, it had a dialed pedometer to perform additions and subtractions. A study of the surviving notes shows a machine that would have jammed after a few entries on the same dial, and that it could be damaged if a carry had to be propagated over a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
