The laws of science called scientific laws or scientific principles, are statements that describe or predict a range of natural phenomena. Each scientific law is a statement based on repeated experimental observations that describes some aspect of the Universe; the term law has diverse usage in many cases across all fields of natural science. Scientific laws summarize and explain a large collection of facts determined by experiment, are tested based on their ability to predict the results of future experiments, they are developed either from facts or through mathematics, are supported by empirical evidence. It is understood that they reflect causal relationships fundamental to reality, are discovered rather than invented. Scientific laws summarize the results of experiments or observations within a certain range of application. In general, the accuracy of a law does not change when a new theory of the relevant phenomenon is worked out, but rather the scope of the law's application, since the mathematics or statement representing the law does not change.
As with other kinds of scientific knowledge, laws do not have absolute certainty, it is always possible for a law to be contradicted, restricted, or extended by future observations. A law can be formulated as one or several statements or equations, so that it can be used to predict the outcome of an experiment, given the circumstances of the processes taking place. Laws differ from hypotheses and postulates, which are proposed during the scientific process before and during validation by experiment and observation. Hypotheses and postulates are not laws since they have not been verified to the same degree and may not be sufficiently general, although they may lead to the formulation of laws. A law is a more formal statement, distilled from repeated experiment. Laws are narrower in scope than scientific theories, which may contain several laws. Science distinguishes a theory from facts. Calling a law a fact is an overstatement, or an equivocation. Although the nature of a scientific law is a question in philosophy and although scientific laws describe nature mathematically, scientific laws are practical conclusions reached by the scientific method.
According to the unity of science thesis, all scientific laws follow fundamentally from physics. Laws which occur in other sciences follow from physical laws. From mathematically fundamental viewpoints, universal constants emerge from a scientific law. A scientific law always applies under the same conditions, implies that there is a causal relationship involving its elements. Factual and well-confirmed statements like "Mercury is liquid at standard temperature and pressure" are considered too specific to qualify as scientific laws. A central problem in the philosophy of science, going back to David Hume, is that of distinguishing causal relationships from principles that arise due to constant conjunction. Laws differ from scientific theories in that they do not posit a mechanism or explanation of phenomena: they are distillations of the results of repeated observation; as such, a law is limited in applicability to circumstances resembling those observed, may be found false when extrapolated.
Ohm's law only applies to linear networks, Newton's law of universal gravitation only applies in weak gravitational fields, the early laws of aerodynamics such as Bernoulli's principle do not apply in case of compressible flow such as occurs in transonic and supersonic flight, Hooke's law only applies to strain below the elastic limit, etc. These laws remain useful, but only under the conditions. Many laws take mathematical forms, thus can be stated as an equation; the first law of thermodynamics can be written as d U = δ Q − δ W. The term "scientific law" is traditionally associated with the natural sciences, though the social sciences contain laws. An example of a scientific law in social sciences is Zipf's law. Like theories and hypotheses, laws make predictions, can be falsified if they are found in contradiction with new data. Most significant laws in science are conservation laws; these fundamental laws follow from homogeneity of space and phase, in other words symmetry. Noether's theorem: Any quantity which has a continuous differentiable symmetry in the action has an associated conservation law.
Conservation of mass was the first law of this type to be understood, since most macroscopic physical processes involving masses, for example collisions of massive particles or fluid flow, provide the apparent belief that mass is conserved. Mass conservation was observed to be true for all chemical reactions. In general this is only approximative, because with the advent of relativity and experiments in nuclear and particle physics: mass can be transformed into energy and vice versa, so mass is not always conserved, but part of the more general conservation of mass-energy. Conservation of energy and angular momentum for isolated systems can be found to be symmetries in time and rotation. Conservation of charge was realized since c
Hick's law, or the Hick–Hyman law, named after British and American psychologists William Edmund Hick and Ray Hyman, describes the time it takes for a person to make a decision as a result of the possible choices he or she has: increasing the number of choices will increase the decision time logarithmically. The Hick–Hyman law assesses cognitive information capacity in choice reaction experiments; the amount of time taken to process a certain amount of bits in the Hick–Hyman law is known as the rate of gain of information. Hick's law is sometimes cited to justify menu design decisions. For example, to find a given word in a randomly ordered word list, scanning of each word in the list is required, consuming linear time, so Hick's law does not apply. However, if the list is alphabetical and the user knows the name of the command, he or she may be able to use a subdividing strategy that works in logarithmic time. In 1868, Franciscus Donders reported the relationship between having multiple stimuli and choice reaction time.
In 1885, J. Merkel discovered that the response time is longer when a stimulus belongs to a larger set of stimuli. Psychologists began to see similarities between this information theory. Hick first began experimenting with this theory in 1951, his first experiment involved 10 lamps with corresponding Morse code keys. The lamps would light at random every five seconds; the choice reaction time was recorded with the number of choices ranging from 2–10 lamps. Hick performed a second experiment using the same task, while keeping the number of alternatives at 10; the participant performed the task the first two times with the instruction to perform the task as as possible. For the last task, the participant was asked to perform the task as as possible. While Hick was stating that the relationship between reaction time and the number of choices was logarithmic, Hyman wanted to better understand the relationship between the reaction time and the mean number of choices. In Hyman’s experiment, he had eight different lights arranged in a 6x6 matrix.
Each of these different lights was given a name, so the participant was timed in the time it took to say the name of the light after it was lit. Further experiments changed the number of each different type of light. Hyman was responsible for determining a linear relation between reaction time and the information transmitted. Given n probable choices, the average reaction time T required to choose among the choices is approximately: T = b ⋅ log 2 where b is a constant that can be determined empirically by fitting a line to measured data; the logarithm expresses depth of "choice tree" hierarchy – log2 indicates binary search was performed. Addition of 1 to n takes into account the "uncertainty about whether to respond or not, as well as about which response to make."In the case of choices with unequal probabilities, the law can be generalized as: T = b H where H is related to the information-theoretic entropy of the decision, defined as H = ∑ i n p i log 2 where pi refers to the probability of the ith alternative yielding the information-theoretic entropy.
Hick's law is similar in form to Fitts's law. Hick's law has a logarithmic form because people subdivide the total collection of choices into categories, eliminating about half of the remaining choices at each step, rather than considering each and every choice one-by-one, which would require linear time. E. Roth demonstrated a correlation between IQ and information processing speed, the reciprocal of the slope of the function: Reaction Time = Movement Time + log 2 Processing Speed where n is the number of choices; the time it takes to come to a decision is: Processing Speed ⋅ log 2 The stimulus–response compatibility is known to affect the choice reaction time for the Hick–Hyman law. This means; the action the user performs is similar to the response. Studies suggest that the search for a word within a randomly ordered list—in which the reaction time increases linearly according to the number of items—does not allow for the generalization of the scientific law, considering that, in other conditions, the reaction time may not be linearly associated to the logarithm of the number of elements or show other variations of the basic plane.
Exceptions to Hick's law have been identified in studies of verbal response to familiar stimuli, where there is no relationship or only a subtle increase in the reaction time associated with an increased number of elements, saccade responses, where it was shown that there is either no relationship, or a decrease in the saccadic time with the increase of the number of elements, thus an antagonistic effect to that postulated by Hick's law. The generalization of Hick's law was tested in studies on the predictability
York University is a public research university in Toronto, Canada. It is Canada's third-largest university, it has 52,300 students, 7,000 faculty and staff, 295,000 alumni worldwide, it has eleven faculties, including the Faculty of Liberal Arts & Professional Studies, Faculty of Science, Lassonde School of Engineering, Schulich School of Business, Osgoode Hall Law School, Glendon College, Faculty of Education, Faculty of Health, Faculty of Environmental Studies, Faculty of Graduate Studies, the School of the Arts, Media and Design, 28 research centres. The Keele campus is home to a satellite location of Seneca College. York University was established in 1959 as a non-denominational institution by the York University Act, which received Royal Assent in the Legislative Assembly of Ontario on 26 March of that year, its first class was held in September 1960 in Falconer Hall on the University of Toronto campus with a total of 76 students. In the fall of 1961, York moved to its first campus, Glendon College, began to emphasize liberal arts and part-time adult education.
In 1965, the university opened a second campus, the Keele Campus, in North York, within the neighbourhood community of York University Heights. Several of York's programs have gained notable recognition both nationally and internationally. York houses Canada's oldest film school, ranked one of the best in Canada, with an acceptance rate comparable to that of USC School of Cinematic Arts and Tisch School of the Arts. York's Osgoode Hall Law School was ranked second best in Canada, in Maclean's 2012 ranking of Canadian common law schools. In The Economist's 2011 full-time MBA rankings, York's Schulich School of Business ranked ninth in the world, first in Canada, in CNN Expansion's ranking of MBA programs, Schulich ranked 18th in the world, placing first in Canada. York's School of Kinesiology and Health Science ranked 1st in Canada and 16th best in the world by ShanghaiRanking in 2017. Over the last twenty years, York has become a centre for labour strife with several faculty and other strikes occurring, including the longest university strike in Canadian history in 2018.
York University was established in 1959 as a non-denominational institution by the York University Act, which received Royal Assent in the Legislative Assembly of Ontario on 26 March of that year. Its first class was held in September 1960 in Falconer Hall on the University of Toronto campus with a total of 76 students; the policy of university education initiated in the 1960s responded to population pressure and the belief that higher education was a key to social justice and economic productivity for individuals and for society. The governance was modelled on the provincial University of Toronto Act of 1906, which established a bicameral system of university government consisting of a senate, responsible for academic policy, a board of governors exercising exclusive control over financial policy and having formal authority in all other matters; the president, appointed by the board, was to provide a link between the two bodies and to perform institutional leadership. In the fall of 1961, York moved to its first campus, Glendon College, began to emphasize liberal arts and part-time adult education.
It became independent in 1965, after an initial period of affiliation with the University of Toronto, under the York University Act, 1965. Its main campus on the northern outskirts of Toronto opened in 1965. Murray Ross, who continues to be honoured today at the University in several ways – including the Murray G. Ross Award – was still vice-president of U of T when he was approached to become York University's new president. At the time, York University was envisaged as a feeder campus to U of T, until Ross's powerful vision led it to become a separate institution. In 1965, the university opened a second campus, the Keele Campus, in North York, in the Jane and Finch community; the Glendon campus became a bilingual liberal arts college led by Escott Reid, who envisaged it as a national institution to educate Canada's future leaders, a vision shared by Prime Minister Lester Pearson, who formally opened Glendon College in 1966. The first Canadian undergraduate program in dance opened at York University in 1970.
In 1972, Canada Post featured the nascent institution on 8¢ stamps, entitled York University Campus, North York, Ont. The first Canadian PhD. program in Women's Studies opened with five candidates in January 1992. Its bilingual mandate and focus on the liberal arts continue to shape Glendon's special status within York University; the new Keele Campus was regarded as somewhat isolated, in a industrialized part of the city. Petrol storage facilities are still across the street; some of the early architecture was unpopular with many, not only for the brutalist designs, but the vast expanses between buildings, not viewed as suitable for the climate. In the last two decades, the campus has been intensified with new buildings, including a dedicated student centre and new fine arts, computer science and business administration buildings, a small shopping mall, a hockey arena; the Aviva Centre tennis stadium, built in 2004, is a perennial host of the Canada Masters tennis tournament. As Toronto has spread further out, York has found itself in a central location within the built-up Greater Toronto Area, in particular, near the Jane and Finch neighbourhood.
Its master plan envisages a denser on-campus environment commensurate with that location. Students occupied the university's administration offices in March 1997, protesting escalating tuition hikes. York University has a history of teaching assistant strikes. In 1997, there w
A pointing device is an input interface that allows a user to input spatial data to a computer. CAD systems and graphical user interfaces allow the user to control and provide data to the computer using physical gestures by moving a hand-held mouse or similar device across the surface of the physical desktop and activating switches on the mouse. Movements of the pointing device are echoed on the screen by movements of the pointer and other visual changes. Common gestures are drag and drop. While the most common pointing device by far is the mouse, many more devices have been developed. However, the term "mouse" is used as a metaphor for devices that move the cursor. For most pointing devices, Fitts's law can be used to predict the speed with which users can point at an higher speed. To classify several pointing devices, a certain number of features can be considered. For example, the device's movement, positioning or resistance; the following points should provide an overview of the different classifications.
Direct vs. indirect inputIn case of a direct-input pointing device, the on-screen pointer is at the same physical position as the pointing device. An indirect-input pointing device is not at the same physical position as the pointer but translates its movement onto the screen. Absolute vs. relative movementAn absolute-movement input device provides a consistent mapping between a point in the input space and a point in the output space. A relative-movement input device maps displacement in the input space to displacement in the output state, it therefore controls the relative position of the cursor compared to its initial position. Isotonic vs. elastic vs. isometricAn isotonic pointing device is movable and measures its displacement whereas an isometric device is fixed and measures the force which acts on it. An elastic device increases its force resistance with displacement. Position control vs. rate controlA position-control input device directly changes the absolute or relative position of the on-screen pointer.
A rate-control input device changes the speed and direction of the movement of the on-screen pointer. Translation vs. rotationAnother classification is the differentiation between whether the device is physically translated or rotated. Degrees of freedomDifferent pointing devices have different degrees of freedom. A computer mouse has namely its movement on the x - and y-axis; however the Wiimote has 6 degrees of freedom: x-, y- and z-axis for movement as well as for rotation. Possible statesAs mentioned in this article, pointing devices have different possible states. Examples for these states are out of range, dragging. Examples a computer mouse is an indirect, isotonic, position-control, translational input device with two degrees of freedom andthree states. A touch screen is a direct, isometric, position-control input device with two degrees of freedom andtwo states. A joystick is an indirect, elastic, rate-control, translational input device with two degrees of freedom andtwo states. A Wiimote is an indirect, elastic, rate-control, translational input device with six degrees of freedom andtwo states.
The following table shows a classification of pointing devices by their number of dimensions and which property is sensed introduced by Bill Buxton. The sub-rows distinguish between mechanical touch-sensitive, it is rooted in the human motor/sensory system. Continuous manual input devices are categorized. Sub-columns distinguish devices; the table is based on the original graphic of Bill Buxton's work on "Taxonomies of Input". This model describes different states; the three common states as described by Buxton are out of range and dragging. Not every pointing device can switch to all states. Fitts's law is a predictive model of human movement used in human–computer interaction and ergonomics; this scientific law predicts that the time required to move to a target area is a function of the ratio between the distance to the target and the width of the target. Fitts's law is used to model the act of pointing, either by physically touching an object with a hand or finger, or by pointing to an object on a computer monitor using a pointing device.
In other words, this means for example, that the user needs more time to click on a small button, distant to the cursor, than he needs to click a large button near the cursor. Thereby it is possible to predict the speed, needed for a selective movement to a certain target; the common metric to calculate the average time to complete the movement is the following: MT = a + b ⋅ ID = a + b ⋅ log 2 where: MT is the average time to complete the movement. A and b are constants that depend on the choice of input device and are determined empirically by regression analysis. ID
A computer mouse is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is translated into the motion of a pointer on a display, which allows a smooth control of the graphical user interface; the first public demonstration of a mouse controlling a computer system was in 1968. Wired to a computer, many modern mice are cordless, relying on short-range radio communication with the connected system. Mice used a ball rolling on a surface to detect motion, but modern mice have optical sensors that have no moving parts. In addition to moving a cursor, computer mice have one or more buttons to allow operations such as selection of a menu item on a display. Mice also feature other elements, such as touch surfaces and "wheels", which enable additional control and dimensional input; the earliest known publication of the term mouse as referring to a computer pointing device is in Bill English's July 1965 publication, "Computer-Aided Display Control" originating from its resemblance to the shape and size of a mouse, a rodent, with the cord resembling its tail.
The plural for the small rodent is always "mice" in modern usage. The plural of a computer mouse is "mouses" and "mice" according to most dictionaries, with "mice" being more common; the first recorded plural usage is "mice". The term computer mouses may be used informally in some cases. Although, the plural of mouse is mice, the two words have undergone a differentiation through usage; the trackball, a related pointing device, was invented in 1946 by Ralph Benjamin as part of a post-World War II-era fire-control radar plotting system called Comprehensive Display System. Benjamin was working for the British Royal Navy Scientific Service. Benjamin's project used analog computers to calculate the future position of target aircraft based on several initial input points provided by a user with a joystick. Benjamin felt that a more elegant input device was needed and invented what they called a "roller ball" for this purpose; the device was patented in 1947, but only a prototype using a metal ball rolling on two rubber-coated wheels was built, the device was kept as a military secret.
Another early trackball was built by British electrical engineer Kenyon Taylor in collaboration with Tom Cranston and Fred Longstaff. Taylor was part of the original Ferranti Canada, working on the Royal Canadian Navy's DATAR system in 1952. DATAR was similar in concept to Benjamin's display; the trackball used four disks to pick up two each for the X and Y directions. Several rollers provided mechanical support; when the ball was rolled, the pickup discs spun and contacts on their outer rim made periodic contact with wires, producing pulses of output with each movement of the ball. By counting the pulses, the physical movement of the ball could be determined. A digital computer calculated the tracks and sent the resulting data to other ships in a task force using pulse-code modulation radio signals; this trackball used a standard Canadian five-pin bowling ball. It was not patented. Douglas Engelbart of the Stanford Research Institute has been credited in published books by Thierry Bardini, Paul Ceruzzi, Howard Rheingold, several others as the inventor of the computer mouse.
Engelbart was recognized as such in various obituary titles after his death in July 2013. By 1963, Engelbart had established a research lab at SRI, the Augmentation Research Center, to pursue his objective of developing both hardware and software computer technology to "augment" human intelligence; that November, while attending a conference on computer graphics in Reno, Engelbart began to ponder how to adapt the underlying principles of the planimeter to X-Y coordinate input. On November 14, 1963, he first recorded his thoughts in his personal notebook about something he called a "bug," which in a "3-point" form could have a "drop point and 2 orthogonal wheels." He wrote that the "bug" would be "easier" and "more natural" to use, unlike a stylus, it would stay still when let go, which meant it would be "much better for coordination with the keyboard."In 1964, Bill English joined ARC, where he helped Engelbart build the first mouse prototype. They christened the device the mouse as early models had a cord attached to the rear part of the device which looked like a tail, in turn resembled the common mouse.
As noted above, this "mouse" was first mentioned in print in a July 1965 report, on which English was the lead author. On 9 December 1968, Engelbart publicly demonstrated the mouse at what would come to be known as The Mother of All Demos. Engelbart never received any royalties for it, as his employer SRI held the patent, which expired before the mouse became used in personal computers. In any event, the invention of the mouse was just a small part of Engelbart's much larger project of augmenting human intellect. Several other experimental pointing-devices developed for Engelbart's oN-Line System exploited different body movements – for example, head-mounted devices attached to the chin or nose – but the mouse won out because of its speed and convenience; the first mouse, a bulky device used two potentiometers perpendicular to each other and connected to wheels: the rotation of each wheel translated into motion along one axis. At the time of the "Mother of All Demos", Engelbart's group had been using their second generation, 3-button mouse for about a year.
On October 2, 1968, a mouse device named Rollkugel (German for "rolling bal
In computing, an input device is a piece of computer hardware equipment used to provide data and control signals to an information processing system such as a computer or information appliance. Examples of input devices include keyboards, scanners, digital cameras and joysticks. Audio input devices may be used for purposes including speech recognition. Many companies are utilizing speech recognition to help assist users to use their device. Input devices can be categorized based on: modality of input whether the input is discrete or continuous the number of degrees of freedom involved'Keyboards' are a human interface device, represented as a layout of buttons; each button, or key, can be used to either input a linguistic character to a computer, or to call upon a particular function of the computer. They act as the main text entry interface for most users. Traditional keyboards use spring-based buttons, though newer variations employ virtual keys, or projected keyboards, it is typewriter like device composed of a matrix of switches.
There happens to be another keyboard, like an input device for musical instrument which helps to produce sound. Examples of types of keyboards include: Keyer Keyboard Lighted Program Function Keyboard Thumb Keyboard Pointing devices are the most used input devices today. A pointing device is any human interface device that allows a user to input spatial data to a computer. In the case of mouse and touchpads, this is achieved by detecting movement across a physical surface. Analog devices, such as 3D mice, joysticks, or pointing sticks, function by reporting their angle of deflection. Movements of the pointing device are echoed on the screen by movements of the pointer, creating a simple, intuitive way to navigate a computer's graphical user interface. Pointing devices, which are input devices used to specify a position in space, can further be classified according to: Whether the input is direct or indirect. With direct input, the input space coincides with the display space, i.e. pointing is done in the space where visual feedback or the pointer appears.
Touchscreens and light pens involve direct input. Examples involving indirect input include the trackball. Whether the positional information is absolute or relative For pointing devices, direct input is necessarily absolute, but indirect input may be either absolute or relative. For example, digitizing graphics tablets that do not have an embedded screen involve indirect input and sense absolute positions and are run in an absolute input mode, but they may be set up to simulate a relative input mode like that of a touchpad, where the stylus or puck can be lifted and repositioned. Embeded LCD tablets which are referred to as graphics tablet monitor is the extension of digitizing graphics tablets, it enables users to see the real-time positions via the screen while using. Examples of types of pointing devices include: mouse touchpad pointing stick touchscreen trackball Some devices allow many continuous degrees of freedom as input; these can be used as pointing devices, but are used in ways that don't involve pointing to a location in space, such as the control of a camera angle while in 3D applications.
These kinds of devices are used in virtual reality systems, where input that registers six degrees of freedom is required. Input devices, such as buttons and joysticks, can be combined on a single physical device that could be thought of as a composite device. Many gaming devices have controllers like this. Technically mice are composite devices, as they both track movement and provide buttons for clicking, but composite devices are considered to have more than two different forms of input. Examples of types of composite devices include: Joystick controller Gamepad Paddle Jog dial/shuttle Wii Remote Video input devices are used to digitize images or video from the outside world into the computer; the information can be stored in a multitude of formats depending on the user's requirement. Examples of types of a video input devices include: Digital camera Digital camcorder Portable media player Webcam Microsoft Kinect Sensor Image scanner Fingerprint scanner Barcode reader 3D scanner Laser rangefinder Eye gaze tracker Computed tomography Magnetic resonance imaging Positron emission tomography Medical ultrasonography Audio input devices are used to capture sound.
In some cases, an audio output device can be used as an input device, in order to capture produced sound. Audio input devices allow a user to send audio signals to a computer for processing, recording, or carrying out commands. Devices such as microphones allow users to speak to the computer in order to record a voice message or navigate software. Aside from recording, audio input devices are used with speech recognition software. Examples of types of audio input devices include: Microphones MIDI keyboard or other digital musical instrument Punched cards and punched tapes were much used in the 20th century. A punched hole represented a one. There were optical readers. Gesture recognition Digital pen Magnetic ink character recognition Sip-and-puff#Computer input device Peripheral Display device Output device N. P. Milner. 1988 A review of human performance and preferences with different input devices to computer systems. In Proceedings of the Fourth Conference of the
Xerox Corporation is an American global corporation that sells print and digital document and services in more than 160 countries. Xerox is headquartered in Norwalk, though its largest population of employees is based around Rochester, New York, the area in which the company was founded; the company purchased Affiliated Computer Services for $6.4 billion in early 2010. As a large developed company, it is placed in the list of Fortune 500 companies. On December 31, 2016, Xerox separated its business process service operations into a new publicly traded company, Conduent. Xerox focuses on its document technology and document outsourcing business, continues to trade on the NYSE. On January 31, 2018, Xerox announced that it would sell a controlling stake to Fujifilm, which has maintained a joint venture in the Asia-Pacific region known as Fuji Xerox. Researchers at Xerox and its Palo Alto Research Center invented several important elements of personal computing, such as the desktop metaphor GUI, the computer mouse and desktop computing.
These concepts were frowned upon by the board of directors, who ordered the Xerox engineers to share them with Apple technicians. The concepts were adopted by Apple and Microsoft. With the help of these innovations and Microsoft came to dominate the personal computing revolution of the 1980s, whereas Xerox was not a major player. Xerox was founded in 1906 in Rochester as The Haloid Photographic Company, which manufactured photographic paper and equipment. In 1938 Chester Carlson, a physicist working independently, invented a process for printing images using an electrically charged photoconductor-coated metal plate and dry powder "toner". However, it would take more than 20 years of refinement before the first automated machine to make copies was commercialized, using a document feeder, scanning light, a rotating drum. Joseph C. Wilson, credited as the "founder of Xerox", took over Haloid from his father, he saw the promise of Carlson's invention and, in 1946, signed an agreement to develop it as a commercial product.
Wilson remained as President/CEO of Xerox until 1967 and served as Chairman until his death in 1971. Looking for a term to differentiate its new system, Haloid coined the term xerography from two Greek roots meaning "dry writing". Haloid subsequently changed its name to Haloid Xerox in 1958 and Xerox Corporation in 1961. Before releasing the 914, Xerox tested the market by introducing a developed version of the prototype hand-operated equipment known as the Flat-plate 1385; the 1385 was not a viable copier because of its speed of operation. As a consequence, it was sold as a platemaker for the Addressograph-Multigraph Multilith 1250 and related sheet-fed offset printing presses in the offset lithography market, it was little more than a high quality, commercially available plate camera mounted as a horizontal rostrum camera, complete with photo-flood lighting and timer. The glass film/plate had been replaced with a selenium-coated aluminum plate. Clever electrics turned this into reusable substitute for film.
A skilled user could produce fast and metal printing plates of a higher quality than any other method. Having started as a supplier to the offset lithography duplicating industry, Xerox now set its sights on capturing some of offset's market share; the 1385 was followed by the first automatic xerographic printer, the Copyflo, in 1955. The Copyflo was a large microfilm printer which could produce positive prints on roll paper from any type of microfilm negative. Following the Copyflo, the process was scaled down to produce the 1824 microfilm printer. At about half the size and weight, this still sizable machine printed onto hand-fed, cut-sheet paper, pulled through the process by one of two gripper bars. A scaled-down version of this gripper feed system was to become the basis for the 813 desktop copier; the company came to prominence in 1959 with the introduction of the Xerox 914, "the most successful single product of all time." The 914, the first plain paper photocopier was developed by John H. Dessauer.
The product was sold by an innovative ad campaign showing that monkeys could make copies at the touch of a button - simplicity would become the foundation of future Xerox products and user interfaces. Revenues leaped to over $500 million by 1965. In the 1960s, Xerox held a dominant position in the photocopier market, the company expanded making millionaires of some long-suffering investors who had nursed the company through the slow research and development phase of the product. In 1960, a xerography research facility called the Wilson Center for Research and Technology was opened in Webster, New York. In 1961, the company changed its name to Xerox Corporation. Xerox common stock was listed on the New York Stock Exchange in 1961 and on the Chicago Stock Exchange in 1990. In 1963 Xerox introduced the Xerox 813, the first desktop plain-paper copier, realizing Carlson's vision of a copier that could fit on anyone's office desk. Ten years in 1973, a basic, color copier, based on the 914, followed.
The 914 itself was sped up to become the 420 and 720. The 813 was developed into the 330 and 660 products and also the 740 desktop microfiche printer. Xerox's first foray into duplicating, as distinct from copying, was with the Xerox 2400, introduced in 1966; the model number denoted the number of prints produced in an hour. Although not as fast as offset printing, this machine introduced the industry's first automatic document feeder, paper slitter and perforator, collato