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Leibniz Wheel
A Leibniz wheel or stepped drum is a cylinder with a set of teeth of incremental lengths which, when coupled to a counting wheel, can be used in the calculating engine of a class of mechanical calculators. Invented by Leibniz in 1673, it was used for three centuries until the advent of the electronic calculator in the mid-1970s. Gottfried Wilhelm Leibniz built a machine called the stepped reckoner based on the design of the stepped drum in 1694. It was made famous by Thomas de Colmar when he used it, a century and a half later, in his Arithmometer, the first mass-produced calculating machine. It was also used in the Curta calculator, a very popular portable calculator introduced in the second part of the 20th century. Concept By coupling a Leibniz wheel with a counting wheel free to move up and down its length, the counting wheel can mesh with any number of teeth. The animation on the side shows a nine-tooth Leibniz wheel coupled to a red counting wheel. It is set to mesh wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylindre De Leibniz Animé
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infinite curvilinear surface in various modern branches of geometry and topology. The shift in the basic meaning—solid versus surface (as in ball and sphere)—has created some ambiguity with terminology. The two concepts may be distinguished by referring to solid cylinders and cylindrical surfaces. In the literature the unadorned term cylinder could refer to either of these or to an even more specialized object, the ''right circular cylinder''. Types The definitions and results in this section are taken from the 1913 text ''Plane and Solid Geometry'' by George Wentworth and David Eugene Smith . A ' is a surface consisting of all the points on all the lines which are parallel to a given line and which pass through a fixed plane curve in a p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmometer Colmar 1852
The arithmometer (french: arithmomètre) was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and could perform long multiplications and divisions effectively by using a movable accumulator for the result. Patented in France by Thomas de Colmar in 1820 and manufactured from 1851 to 1915, it became the first commercially successful mechanical calculator.Chase G.C.: ''History of Mechanical Computing Machinery'', Vol. 2, Number 3, July 1980, page 204, IEEE Annals of the History of Computing https://archive.org/details/ChaseMechanicalComputingMachinery Its sturdy design gave it a strong reputation for reliability and accuracy and made it a key player in the move from to calculating machines that took place during the second half of the 19th century. Its production debut of 1851 launched the mechanical calculator industry which ultimately built million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curta Calculator
The Curta is a hand-held mechanical calculator designed by Curt Herzstark. It is known for its extremely compact design: a small cylinder that fits in the palm of the hand. It was affectionately known as the "pepper grinder" or "peppermill" due to its shape and means of operation; its superficial resemblance to a certain type of hand grenade also earned it the nickname "math grenade". Curtas were considered the best portable calculators available until they were displaced by electronic calculators in the 1970s. History The Curta was conceived by Curt Herzstark in the 1930s in Vienna, Austria. By 1938, he had filed a key patent, covering his complemented stepped drum. This single drum replaced the multiple drums, typically around 10 or so, of contemporary calculators, and it enabled not only addition, but subtraction through nines complement math, essentially subtracting by adding. The nines' complement math breakthrough eliminated the significant mechanical complexity c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curt Herzstark
Curt Herzstark (January 26, 1902 – October 27, 1988) was an Austrian engineer. During World War II, he designed plans for a mechanical pocket calculator (the ''Curta''). Life and career Herzstark was born in Vienna, the son of Marie and Samuel Jakob Herzstark. His father was Jewish and his mother, born a Catholic, converted to Lutheranism and raised Herzstark Lutheran. In 1938, while he was technical manager of his father's company Rechenmaschinenwerk AUSTRIA Herzstark & Co., Herzstark had already completed the design of the Curta, but could not manufacture it due to the Nazi German annexation of Austria. Instead, the company was ordered to make measuring devices for the German Army. In 1943, perhaps influenced by the fact that his father was a liberal Jew, the Nazis arrested him for "helping Jews and subversive elements" and "indecent contacts with Aryan women" and sent him to the Buchenwald concentration camp. However, the reports of the army about the precision-productio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmaurel
The Arithmaurel was a mechanical calculator that had a very intuitive user interface, especially for multiplying and dividing numbers because the result was displayed as soon as the operands were entered. It was first patented in France by Timoleon Maurel, in 1842. It received a gold medal at the French national show in Paris in 1849. Unfortunately its complexity and the fragility of its design prevented it from being manufactured. Its name came from the concatenation of Arithmometer The arithmometer (french: arithmomètre) was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. This calculator could add and subtract two numbers directly and could perform long ..., the machine that inspired its design and of Maurel, the name of its inventor. The heart of the machine uses one Leibniz stepped cylinder driven by a set of differential gears. History Timoleon Maurel patented an early version of his machine in 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Xavier Thomas
Charles Xavier Thomas de Colmar (May 5, 1785 – March 12, 1870) was a French inventor and entrepreneur best known for designing, patenting and manufacturing the first commercially successful mechanical calculator, the Arithmometer, and for founding the insurance companies ''Le Soleil'' and ''L'aigle'' which, under his leadership, became the number one insurance group in France at the beginning of the Second Empire. Biography Born Charles Xavier Thomas in Colmar, France, his father was a doctor and member of the town council. After a short employment in the French administration, Thomas joined the French army in 1809 eventually reaching the level of General Manager of the supply store of all of the armies located in Spain in 1813. Shortly thereafter he was promoted to Inspector of Supply for the entire French army. It was during that time that he conceived the idea of the Arithmometer to help him with the great deal of calculations that he had to perform. Back into civilian li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FELT
Felt is a textile material that is produced by matting, condensing and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood pulp–based rayon. Blended fibers are also common. Natural fibre felt has special properties that allow it to be used for a wide variety of purposes. "It is fire-retardant and self-extinguishing; it dampens vibration and absorbs sound; and it can hold large amounts of fluid without feeling wet..." History Felt from wool is one of the oldest known textiles. Many cultures have legends as to the origins of felt making. Sumerian legend claims that the secret of feltmaking was discovered by Urnamman of Lagash. The story of Saint Clement and Saint Christopher relates that the men packed their sandals with wool to prevent blisters while fleeing from persecution. At the end of their journey, the movement and sweat had turned the wool into f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinwheel Calculator
A pinwheel calculator is a class of mechanical calculator described as early as 1685, and popular in the 19th and 20th century, calculating via wheels whose number of teeth were adjustable. These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a counter they could, at each rotation, add a number from 0 to 9 to the result. By linking these wheels with carry mechanisms a new kind of calculator engine was invented. Turn the wheels one way and one performs an addition, the other way a subtraction. As part of a redesign of the arithmometer, they reduced by an order of magnitude the cost and the size of mechanical calculators on which one could easily do the four basic operations (add, subtract, multiply and divide). Pinwheel calculators became extremely popular with the success of Thomas' Arithmometer (manufactured 1850s) and Odhner Arithmometer (manufactured 1890s). History * - In "M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Stanhope, 3rd Earl Stanhope
Charles Stanhope, 3rd Earl Stanhope, aka Charles Mahon, 3rd Earl Stanhope, FRS (3 August 175315 December 1816), was a British statesman, inventor, and scientist. He was the father of Lady Hester Stanhope and brother-in-law of William Pitt the Younger. He is sometimes confused with an exact contemporary of his, Charles Stanhope, 3rd Earl of Harrington. Early life The son of Philip Stanhope, 2nd Earl Stanhope, he was educated at Eton and the University of Geneva. While in Geneva, he devoted himself to the study of mathematics under Georges-Louis Le Sage, and acquired from Switzerland an intense love of liberty. Politics In politics he was a democrat. As Lord Mahon he contested the Westminster without success in 1774, when only just of age; but from the general election of 1780 until his accession to the peerage on 7 March 1786 he represented through the influence of Lord Shelburne the Buckinghamshire borough of High Wycombe. During the sessions of 1783 and 1784 he supported ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MARGIN
Margin may refer to: Physical or graphical edges *Margin (typography), the white space that surrounds the content of a page *Continental margin, the zone of the ocean floor that separates the thin oceanic crust from thick continental crust *Leaf margin, the edge of a leaf *Resection margin, the tissue near a tumor that is removed to ensure that no cancer cells are left behind Economics and finance *Margin of profit, the fraction of revenue that is left after paying expenses * Margin (economics), a set of constraints conceptualised as a border *Margin (finance), a type of financial collateral used to cover credit risk * ''Margin'' (journal), an economics journal *Contribution margin *Gross margin Figurative edges * Margin (machine learning), the distance between a decision boundary and a data point *Marginal frequency distribution, in statistics ( Frequency distribution § Joint frequency distributions) Other uses * ''Margins'' (film), a 2022 Italian film by Niccolò Falsetti * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gottfried Leibniz
Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of mathematics. He wrote works on philosophy, theology, ethics, politics, law, history and philology. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in probability theory, biology, medicine, geology, psychology, linguistics and computer science. In addition, he contributed to the field of library science: while serving as overseer of the Wolfenbüttel library in Germany, he devised a cataloging system that would have served as a guide for many of Europe's largest libraries. Leibniz's contributions to this vast array of subjects were scattered in various learned journals, in tens of thousands of letters and in unpublished manuscripts. He wrote in several languages, primarily in Latin, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
