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In North America, T-1 is a digital carrier for a DS1-formatted signal.
 Research T-1
In North America, T-3 a digital carrier for a DS3-formatted signal.
Research T-3
A tachograph is a device fitted to a motor vehicle which records its speed and distances travelled.
Tachographs are often called the spy in the cab by lorry drivers who are restricted in how long they may drive for by law.
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A tachometer is a device for measuring the velocity of machines or the rate of flow of liquids. The term was first used to describe a device used for measuring the velocity of running water in a river or canal, and which consisted of a wheel with inclined vanes, which were turned by the current. The rotations of the wheel were then recorded by clockwork.
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A tachyon is a theoretical particle that always travel faster than light.
Research Tachyon
A tack is a small sharp nail, usually with a large flat head. They are used for fitting a light or thin object to a more solid one, such as carpet to the floor.
Research Tack
Tain is a form of thin tin plate or foil used for making mirrors.
Research Tain
Tallow is the harder and less fusible fats of animals, especially sheep and ox, separated from the connective tissue by melting and clarifying and used for making soap, candles and other things. It is composed of the glycerol esters of stearic and oleic, as well as some palmitic acids.
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Tan is the bark of oak, birch, beech and other trees, shredded and steeped in water (the liquor being known as tan ooze) and used for the preparation of leather.
Research Tan
A tang is a projection of a knife or other metal tool by which it is secured to its handle.
Research Tang
Tanghinin is a poison acting on the heart. It is obtained from the almonds of Tanghinia veneifera and is used in Madagascar for trial by ordeal.
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Tanner is an old English slang expression for a sixpence. More properly, a
tanner is someone who tans hides.
Research Tanner
A tannery is a place where hides are tanned.
Research Tannery
Tannin is an astringent substance found in various types of wood, notably oak, and used to tan hides, that is convert them into leather.
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Tantalum is a rare silvery-looking metal element with the symbol Ta. It is found chiefly in tantalite and obtained by reducing to potassium flouro-tantalate by means of sodium followed by fusion in vacuo. Tantalum is used as a wire in electric lamps. Tantalum was discovered by A G Ekeberg in 1802, but the metal was not isolated until 1905. Combined with carbon, tantalum becomes almost as hard as diamond, and has been used to increase the hardness and tensile strength of steel. Tantalum is unaffected by most acids.
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A Tantalus cup is a philosophical toy, consisting of a siphon so adapted to a cup that, the short leg being in the cup, the long leg may go down through the bottom of it. The siphon is concealed within the figure of a man, whose chin is on a level with the bend of the siphon. Hence, as soon as the water rises up to the chin of the image, it begins to subside, so that the figure, Like Tantalus in mythology, is unable to quench its thirst.
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In engineering, a tappet is a projection within a moving shaft which strikes some other moving piece periodically. In motor car construction the term tappet is applied to a short shaft between the foot of a valve and a cam on the camshaft operating a valve.
Research Tappet
Tar is a black, oily liquid with a characteristic odour obtained by the distillation of coal, wood and bituminous minerals. Tar varies in composition according to its source, but all kinds consist largely of hydrocarbons and contain suspended carbon, to which the black colour is due. By subjecting tar to distillation various constituents are separated and are employed as the raw material for making aniline dyes. The solid and brittle mass left after distillation is known as pitch. Tar has been used medicine in the treatment of skin diseases since at least the start of the 20th century.
In computing, tar is the name of the Unix tape archiver program. Files compressed with tar are recognisable by the extension '.tar' or '.tgz'. The contents of the archive may be extracted in various ways. If the archive file has the extension .tar, then the command line 'tar -xvf filename.tar' will work. If the file has the extension '.tgz' or '.tar.gz' then it has also been 'zipped' and the command 'tar -xzvf filename.tar.gz' or 'tar -xzvf filename.tgz' will extract the contents. The contents of an archive may be listed by replacing the parameter letter 'x' with 't' such as 'tar -tvf filename.tar'.
Research Tar
Tar black is a cheap coal-tar product used for such purposes as treating wooden posts which are to be in contact with the soil.
Research Tar Black
Tartar, also known as argal or argol, (potassium tartrate) is a white crust deposited in wine casks during fermentation. The purified crystals are used in cooking, and often called cream of tartar. The term is also used for the concretion deposited upon teeth from saliva and comprised of phosphate of lime.
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Tartaric Acid is a popular name for dihydroxysuccinic acid. It occurs in many plants, particularly in the grape and is easily obtained from tartar.
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Tartrate is a salt of tartaric acid.
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Taxidermy is the art of preparing and mounting the skins of animals in a lifelike manner. In colloquial terms, stuffing dead animals.
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TDB by Netko, is a small, powerful free computer database program for the Windows operating system. With a little bit programming you can make very useful databases with many intelligent reports. The databases and reports are displayed in a tabbed window. With one right-click in a database you can simply maintain the data (edit, add, search, replace and delete records). Clicking on the header buttons allows you sort to data in the required order. Through the menu commands or toolbar you can open, save, import, export or print records or reports. There is a facility provided to generate graph's and display data with attractive shapes. Some statistics functions are also included. There are intelligent commands for reports, multiple field search and replace, extensive ASCII import/export function, integrity self-check to ensure you got the original, uninfected copy of the program and help file.
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Technetium is an artificial element with the symbol Tc.
Research Technetium
Tectonics is the study of rock movements.
Research Tectonics
Teflon is a trade name for the polymer polytetrafluorethylene. It is widely used as a non-stick coating in cookware.
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The telautograph was a form of telegraph (the originator of the modern fax machine) whereby a message or drawing produced at the transmitter was instantly reproduced at the distant receiver.
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Telegony is the theory of pre-paternal influence on offspring. That is, that a previous male mate may pass characteristics to an offspring conceived by the same mother, but a different father. No evidence has been furnished to support the theory, but never the less, it was a popular belief amongst animal breeders.
Research Telegony
Originally the term telegraphy referred to any form of signalling. With the advent of electronic telegraph systems the term became more specific to electronic signalling, and more recently to the transmission of data, as distinct from telephony which signals voice, electronically. E.G.: Morse code by radio wave or through a telephone line. The first telegraph was a system of optical signalling using the shutter system between London and the English channel in the late 18th century. The first electric telegraph was described in the Scots Magazine in 1753 by Charles Morrison, and involved separate wires for each letter of the alphabet. In 1835 Wheatstone invented a five wire telegraph, which he later refined to a two wire system.
The telegraph was first brought into practical use in the United States by Professor Samuel Morse. He began his experiments in 1832, aided by L D Gale and George and Alfred Vail. In 1837 he filed a caveat in the Patent Office at Washington, and in 1840 obtained a patent covering the improvements he had made in the meantime. The first line established was between Baltimore and Washington, it being successfully operated on May the 27th, 1844.
In October, 1842, Morse had attempted to operate a line from Governor's Island to the Battery in New York, but this experiment failed. Samuel Colt, in 1843, laid a submarine cable from Coney Island and Fire Island, at the mouth of New York harbour, up to the city, and operated it successfully for a time. In 1860 it was estimated that there were over 50,000 miles of telegraph lines in operation in the United States, and at the end of the 19th century the lines extended over 190,000 miles.
Research Telegraphy
A telemeter was an instrument for measuring the distance of an object from the observer. Telemeters were used in surveying and by the military during the 19th and early 20th centuries. Later telemeters consisted of a rigid tube, mounted so that it could pivot horizontally and vertically. At each end of the tube and at right angles to its main axis was a telescope, the images being deflected by prisms to an eyepiece at the center of the tube. One prism was fixed to maintain the beam of light at a right angle and the other prism was adjusted either by turning on its axis or sliding along the tube, until the images from the two telescopes coincided. At this point the range of the object being viewed could be read off on a graduated scale.
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Telemetry is one-way radio transmissions used for tracking and measurement data.
Research Telemetry
Teleonomy is the property of living systems of being organized towards the attainment of ends without true purpose
Research Teleonomy
The telephone is an instrument for reproducing speech at a distance from the source. It was invented (or rather patented) by Alexander Graham Bell in 1876 - the invention of the telephone being claimed also by Gray, of Chicago and several others. The possibility of such an instrument was discovered previous to 1873, but the first satisfactory results were not obtained until 1877, when Bell completed and put into practical use a telephone line between Salem and Boston, Gray achieving a like result the same year in a line set up between Chicago and Milwaukee, a distance of eighty-five miles. By 1880 there were in existence in America 148 telephone companies and private concerns, operating 34,305 miles of wire which by 1893 had risen to 308,000 miles. The Bell Company was the most extensive American telephone company in the 19th century. Two suits were brought against the patent, but both failed.
Long distance telephony was developed in the 1920s following the experiments of Dr H. W. Nichols, with links between major cities in the continents introduced in 1927.
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Telephony refers to the reproduction of speech at a distance from the source.
Telephony may occur with the use of a telephone, or through wireless apparatus such as radio equipment.
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A telescope is an instrument which magnifies distant objects. The telescope was first invented in 1609 and in 1610 Galileo using his own made telescope discovered the satellites of Jupiter.
Research Telescope
A telescope joint is an electrical end to end joint used for joining large multi-strand cables where the diameter of the joint must not exceed that of the cable. It is a fairly efficient joint, but will not withstand bending or strain. The outer half of the conductors are cut away from one cable, the inner half of the other cable, before the ends are filled square, and the two cables set together, the ends held with a few turns of binding wire and the joint is soldered. After cooling the binding wire is filled smooth.
Research Telescope Joint
Teletext is a television-based information system. Teletext is a videotex service, transmitting information in the unused area (usually the top four lines) of a normal television signal. By using a special decoder attached to the television set, this information becomes visible on the entire screen as pages of text and graphics.
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Television is a system for seeing distant objects through the intermediary of electro-magnetic waves transmitted through space or over wires. It was first developed during the 1920s.
Research Television
Telex is an international communications network designed on a similar basis to the telephone network, to carry telegraphic messages between teleprinters. For simple messages
telex has the advantage over fax that one telex message can be transmitted to several receivers simultaneously. In 1985 an improved telex system was launched, which can use any public communications network, and is faster and cheaper.
Research Telex
Tellurium is a greyish-white semi-metallic element with a metallic lustre and the symbol Te. A semiconductor, it shows greater conductivity in certain directions, according to the alignment of the atoms. Tellurium is found in small quantities in its native state, but usually combined with metals such as tetradymite or bismuth telluride. Tellurium was named by Klaproth who examined it in 1798. Its compounds are toxic. The chief use of tellurium is in the vulcanisation of rubber. It is also used to colour glass, to increase the hardness of lead in battery plates, and to improve the machinability of stainless steel.
Research Tellurium
Telpherage is a system of traction by aerial ropeway used for the conveyance of minerals over rough country. A stout steel cable supported on poles forms the track and on this are hung small trolleys with wheels running on the cable. A second cable conveys electric current to the trolleys which are driven by motors, each trolley being equipped with its own self-propelling motor.
Research Telpherage
Tempera is a process of spreading a mixture of paint and a glutinous material on a flat surface. It is a process which was popular with early Italian artists.
Research Tempera
The temperature of a substance is a number which expresses its degree of hotness on some chosen scale. It does not relate to the heat energy contained by the object.
Research Temperature
Tempering is the process of heating up a metal, such as steel until red hot and then suddenly or gradually cooling it in water, oil, molten lead or another liquid. The result is to harden the metal. The metal can then be gradually reheated to reduce the hardness down to a required level - very hard metal also being more brittle. Oil and lead tempering produce a metal which though less hard, is not so brittle as metal tempered by water hardening.
Research Tempering
Tempest (Transient Electromagnetic Pulse Surveillance Technology) is the US Government program for evaluation and endorsement of electronic equipment that is safe from eavesdropping. Tempest certification refers to the equipment having passed a testing phase and agreeing to emanations rules specified in the government document NACSIM 5100A (Classified). This document sets forth the emanation levels that the US Government believes equipment can give off without compromising the information it is processing. Computers and other electronic equipment release interference to their surrounding environment. You may observe this by placing two video monitors close together. The pictures will behave erratically until you space them apart. What is important for an observer is the emission of digital pulses (1s and 0s) as these are used in computers. The channel for this radiation is in two arrangements, radiated emissions and conducted emissions. Radiated emissions are assembled when components in electrical devices form to act as antennas.
Conducted emissions are formed when radiation is conducted along cables and wires. Although most of the time these emissions are simply annoyances, they can sometimes be very helpful. If someone wants to see what project a person is working on they can sit in a van outside the target's office and use sensitive electronic equipment to attempt to pick up and decipher the radiated emissions from the target's video monitor. These emissions normally exist at around 55-245 Mhz and can be picked up as far as one kilometre away. A monitoring device can distinguish between different sources emitting radiation because the sources emanating the radiation are made up of dissimilar elements and so this coupled with other factors varies the emitted frequency. For example different electronic components in VDUs, different manufacturing processes involved in reproducing the VDUs, different line syncs, etc.
Research Tempest
A tenon-saw is a fine saw with a thin blade and small teeth designed for cutting tenons.
Research Tenon-Saw
Teratology is the science concerned with the study of occurrences of malformations, monstrosity or abnormal growths in organic life.
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Terbium is a metal element with the symbol Tb belonging to the series known as rare earths.
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Terebine is a very strong liquid drier made by dissolving drying agents such as lead or manganese salts in linseed oil at a high temperature, usually with the addition of rosin, and thinning down the mixture with white spirit.
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Terpene is a chemistry term for any of a large group of cyclic hydrocarbons which form the chief constituents of the volatile oils obtained by distilling plant material (Turpentine).
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Terpineol is a thick liquid produced by the action of dilute acids upon terpine hydrate. It has a smell resembling lilac or hyacinth and is used in perfume and soaps to imitate the smell of these flowers.
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Terra Cotta is a baked clay, or burned earth material similar to that from which pottery is made. It was extensively used in ancient times. Terra Cotta consists of potters' clay and fine powdered silica.
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Tetra-Ethyl-Lead is an organo-metalic compound widely used as an anti-knock agent in leaded petrol.
Research Tetra-Ethyl-Lead
1,1,2,2-Tetrachloroethane is a man-made colourless or pale yellow dense liquid with a penetrating, sweet chloroform-like odour. The only major use for it is as a feedstock in the production of trichloroethylene, tetrachloroethylene, and 1,2-dichloroethylene. It may also be used as a solvent; in cleaning and degreasing metals; in paint and rust removers, varnishes and lacquers; in photographic films; and as an extractant for oils and fats. It was once an ingredient in an insect repellent, but registration was cancelled in the late 1970s. Due to its toxicity and new processes for manufacturing chlorinated ethylenes, the manufacture and use of 1,1,2,2-tetrachloroethane now appears to be very limited. 1,1,2,2-Tetrachloroethane does not burn easily, but produces poisonous gases in a fire, including phosgene and hydrogen chloride. It is soluble in alcohol and ether. It is also known as acetylene tetrachloride; di-chloro-2,2-dichloroethane; s-tetrachloroethane; TCE
tetrachloroethane; and sym-tetrachloroethane.
Research Tetrachloroethane
A tetrode is an electronic amplifying valve with four main electrodes.
Research Tetrode
TeX is an extremely powerful macro-based computer text formatter written by Donald E. Knuth, very popular in the computer-science community. Knuth began TeX because he had become annoyed at the declining quality of the typesetting in volumes I--III of his monumental `Art of Computer Programming'. In a manifestation of the typical hackish urge to solve the problem at hand once and for all, he began to design his own typesetting language. He thought he would finish it on his sabbatical in 1978; he was wrong by only about 8 years. The language was finally frozen around 1985. Though well-written, TeX is so large (and so full of cutting edge technique) that it is said to have unearthed at least one bug in every Pascal it has been compiled with.
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TextPad is a full-featured text editor offering a spelling checker, macros, and powerful formatting and file-storage options for the Windows operating system. Features include colour syntax highlighting, multiple workspaces, customisable toolbars, a dockable document selector, and an alternative tabbed-document selector.
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TextReader V1.1 is an auto-scrolling text reader computer program for the Windows operating system, allowing the user to read through large text and rich-text files (such as Project Gutenberg files) without having to page through the text. The user has the ability to set such features as the scroll rate, font characteristics for the reader and each file. The program also features a text search facility.
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Thallium is a metal element with the symbol Tl.
Research Thallium
The Brooklyn Bridge is a hardware/software package that lets the user link two PCs through their serial or parallel ports to perform file transfers and share DOS devices. Through a master/slave relationship, the two computers are completely integrated, and you can access the disk drives and other DOS devices of one computer from the other. The package allows the transfer of files serially at speeds up to 115,200 bps, or up to 500, 000 through the parallel ports.
The Brooklyn Bridge gives users the option of operating the program through DOS commands, Brooklyn Bridge utilities, or menus. The latter two methods include a context-sensitive help facility. Once installed, the software requires only 5K of memory. The Brooklyn Bridge operates as a DOS device driver, transparently linking two computers to make the remote system's drives appear as the next available drive letters on the machine you are using. For example, a PC with two disk drives and one hard disk occupies drives A:, B:, and C:. The disk drives of a laptop PC are seen as D: and E:. A file is also included to rename the designators of the remote devices so as not to conflict with those of the local PC. For example, if you have LPT1 defined on both the local and remote PC, you can rename the remote LPT1 to LPT2, so both can be accessed from the local PC. Installed as a DOS device driver,
The Brooklyn Bridge becomes more than just a device for file transfers between two computers; it becomes a small network. The Brooklyn Bridge allows the user to read and write to diskette drives and hard disks, and use printers, plotters, clock, calendar and other DOS devices.
Research The Brooklyn Bridge
Early in the twentieth century Albert Einstein put forward new ideas regarding the relationship between space, time, mass and energy which have come to be known as the theory of relativity. It had long been accepted that matter could not be destroyed. This assumption was expressed in the law of conservation of matter, which states that the total quantity of matter in the universe is fixed and cannot be increased or decreased by human agency. Similarly, another law, called the law of conservation of energy, states that the total quantity of energy in the universe is also constant and can be neither created nor destroyed. Einstein simplified the picture of the universe by showing that the mass of a body is a measure of the quantity of energy contained in it. For example, in a nuclear reactor, the sum total of the masses of the atoms produced as a result of fission is slightly less than the mass of the original uranium nuclei. The difference represents the mass of the energy liberated as heat, radiation and kinetic energy of fission
products. Thus we now have to consider the laws of conservation of energy and mass as separate aspects of a single principle and take the view that the sum total of mass plus energy in the universe is fixed.
Research The Conservation of Energy and Mass
A motor is a device for converting electrical energy into mechanical energy. In its simplest form it consists of a rectangular coil which can turn about a horizontal axis. The coil is placed in the uniform field due to the poles of a permanent magnet, the axis being perpendicular to the direction of this field. By the rule for the magnetic effect of a current flowing round a coil, the sides of the coil act like poles of a magnet. If the current is so arranged initially that the sides of the coil are polarised the same as the sides of the magnet they are adjacent to, the coil will turn so that its north polarised side faces the south pole of the magnet. When the plane of the coil reaches the vertical position it overshoots and moves past, just as the mass at the end of a simple pendulum moves past its equilibrium position as it oscillates to and fro. As the coil passes this vertical position, the current in it is made to reverse by a split-ring commutator device and the formerly north pole face of the coil becomes a south pole. It is therefore
repelled by the south pole of the magnet and attracted by the north pole, and thus the coil continues to rotate in the same direction about its axis. When it reaches a vertical position on its way round the current is again reversed by the commutator to make the rotation continue.
Research The Principle of the Electric Motor.
Thebaine is a naturally occurring non-addictive, non-narcotic alkaloid contained in opium. It is coloured red by concentrated sulphuric acid and is very poisonous, causing severe convulsions by its action on the spinal cord and generally resembling strychnine in its results. However, it can also be used to produce codeine and other pain killers, and is very difficult to derive morphine (from which opium is produced) from it.
Research Thebaine
Theine is an alternative name for caffeine, the term theine usually being given to a drug prepared from the dried leaves of certain plants.
Research Theine
Theobromine (dimethyl-xanthine) is the active principal of the cacao or cocoa bean. It is an alkaloid crystalline powder with a bitter taste closely resembling caffeine and sometimes used as a diuretic and has been found to be an effective cough suppressant, more effective than codeine - eating chocolate, particularly plain chocolate, or drinking cocoa can be an effective remedy for coughing.
Research Theobromine
A theodolite is an instrument used in surveying for measuring horizontal and vertical angles.
Research Theodolite
A thermion is an electrically charged particle emitted from a heated body.
Research Thermion
Thermionics is a branch of physics dealing with the emission of ions by hot bodies. The first thermionic observation, though not understood at the time, was made by Thomas Edison, and is known as the Edison effect.
Research Thermionics
A thermistor is a type of semi-conductor in which the resistance decreases as the temperature rises.
Research Thermistor
Thermit is a mixture of coarsely powdered aluminium and magnetic oxide of iron which when ignited - by means of a primer of barium peroxide mixed with aluminium powder into which a piece of magnesium ribbon is placed and ignited - reacts by producing iron and aluminium oxide at an intensely high temperature approaching 3000 degrees Celsius. It was developed for making welding repairs to rails and welding in situ, and was adopted by the army for use in incendiary bombs. German incendiary bombs dropped on Britain during the Great War contained thermit.
Research Thermit
The Thermite Process (Goldschmidt Process) is the method of obtaining liquid metal by reduction of the oxide with aluminium powder.
Research Thermite Process
Thermo-Chemistry is the branch of physical chemistry which deals with the relationship between chemical energy and heat.
Research Thermo-Chemistry
Thermo-Electricity is the phenomena of electricity being produced when a circuit of two different metals is heated, and heat is produced when electrical current is passed through a circuit of two different metals.
Research Thermo-Electricity
Thermodynamics is the study of the laws that govern the conversion of energy from one form to another, the direction in which heat will flow, and the availability of energy to do work. It is based on the concept that in an isolated system anywhere in the universe there is a measurable quantity of energy called the internal energy (U) of the system. This is the total kinetic and potential energy of the atoms and molecules of the system of all kinds that can be transferred directly as heat; it therefore excludes chemical and nuclear energy. The value of U can only be changed if the system ceases to be isolated. In these circumstances U can change by the transfer of mass to or from the system, the transfer of heat (Q) to or from the system, or by the work (W) being done on or by the system. For an adiabatic (Q = 0) system of constant mass, DU = W. By convention, W is taken to be positive if work is done on the system and negative if work is done by the system. For nonadiabatic systems of constant mass, DU = Q + W. This
statement, which is equivalent to the law of conservation of energy, is known as the first law of
thermodynamics. All natural processes conform to this law, but not all processes conforming to it can occur in nature. Most natural processes are irreversible, i.e. they will only proceed in one direction. The direction that a natural process can take is the subject of the second law of
thermodynamics, which can be stated in a variety of ways. R Clausius stated the law in two ways: 'heat cannot be transferred from one body to a second body at a higher temperature without producing some other effect' and 'the entropy of a closed system increases with time'. These statements introduce the thermodynamic concepts of temperature (T) and entropy (S), both of which are parameters determining the direction in which an irreversible process can go. The temperature of a body or system determines whether heat will flow into it or out of it; its entropy is a measure of the unavailability of its energy to do work. Thus T and S determine the relationship between Q and W in the statement of the first law. This is usually presented by stating the second law in the form DU = TDS - W. The second law is concerned with changes in entropy (DS). The third law of thermodynamics provides an absolute scale of values for entropy by stating that for changes involving only perfect crystalline solids at absolute zero, the change of the total entropy is zero.
This law enables absolute values to be stated for entropies. One other law is used in
thermodynamics. Because it is fundamental to, and assumed by, the other laws of thermodynamics it is usually known as the zeroth law of thermodynamics. This states that if two bodies are each in thermal equilibrium with a third body, then all three bodies are in thermal equilibrium with each other.
Research Thermodynamics
A thermograph is a self-registering device for recording fluctuations in air temperature (thermometer). Various forms of thermograph have been made, traditionally they registered the temperature on a clockwork revolving drum sometimes with a pen which traces a curve and sometimes photographically.
Research Thermograph
Thermoluminescence is the luminescence produced in a solid when its temperature is raised. It arises when free electrons and holes, trapped in a solid as a result of exposure to ionising radiation, unite and emit photons of light. The process is made use of in thermoluminescent dating, which assumes that the number of electrons and holes trapped in a sample of pottery is related to the length of time that has elapsed since the pottery was fired. By comparing the luminescence produced by heating a piece of pottery of unknown age with the luminescence produced by heating similar materials of known age, a fairly accurate estimate of the age of an object can be made.
Research Thermoluminescence
A thermometer is a device used to measure temperature. It was invented by Galileo in 1592. The graduation and inclusion of fixed points was added by Sanctorio who used snow and the heat of a candle, dividing the range obtained into degrees. The first sealed thermometer was made by Ferdinand II, the Grand Duke of Tuscany, in 1654. He filled the bulb and part of the tube with alcohol and then melted the glass tip, thereby sealing the tube. In England, Boyle, at the request of the Royal Society, made experiments on thermometers, his lectures on cold being published in 1665. Mercurial thermometers were first employed by the Academia del Climento of Florence in 1657. In 1694 Renaldini suggested the boiling-point of water as the upper limit of the scale. In 1706 Fahrenheit made improvements to the thermometer. In 1714 he made his Fahrenheit
thermometer with three fixed points. He arrived at his zero by taking a mixture of ice water and sal ammoniac; the second point he obtained by mixing ice and water - this point he called 32 degrees, or freezing point, his third mark was blood heat and was obtained by placing the thermometer in the mouth of a healthy man and holding it there until it reached the body temperature. He then divided the distance between the melting point of ice - 32 degrees - and the boiling point of water - 212 degrees - into 180 degree marks. Celsius invented his own scale with the boiling point of water at zero and the freezing point of water at 100 degrees, this scale has now been inverted.
Research Thermometer
A thermostat is a device which automatically maintains temperature at a constant value or gives notice of an undue change in temperature.
Research Thermostat
Thiamine is vitamin b1 a deficiency of which causes beri beri.
Research Thiamine
The thiazines are compounds containing a ring of one nitrogen, one sulphur, and four carbon atoms.
Research Thiazine
A thio-derivative is a compound in which sulphur has replaced an equivalent amount of oxygen, such as potassium thio-cyanate, KCNS, in which the sulphur has replaced the oxygen in potassium cyanate, KCNO.
Research Thio-derivative
Thiophene is a colourless, volatile liquid closely resembling benzene. It occurs in coal-tar and is extracted by shaking with concentrated sulphuric acid. Thiophene is a parent substance of a number of derivatives.
Research Thiophene
Thixotropic paint is a paint which has a jelly-like structure which is broken down when the paint is stirred, shaken, heated or when it is subjected to the shearing action of a brush or roller, and which returns to its jelly-like state a short time after the action ceases. Thixotropic paints claim the advantage that they require no stirring before use, that no settlement takes place during storage and they are easy to apply, being non-drip.
Research Thixotropic Paint
In metallurgy, the Thomas-Gilchrist Process was an important improvement on the Bessemer process of producing steel. It was devised by Sidney Gilchrist Thomas, a magistrate's clerk in London, and put into practical shape by him in conjunction with his cousin, Percy W Gilchrist, a chemist at Blaenavon Ironworks in Wales, where the process was first tried about 1877. The aim of the process is to eliminate phosphorus from the steel produced, and thus to permit the use of pig irons containing the normal proportions of that element. The phosphorus is removed from the molten iron in the converter and concentrated in a slag by adding an excess of lime as flux, the lining of the converter being prepared of a basic material such as dolomite limestone, instead of an acid material such as the ordinary siliceous firebrick. Hence the process is often described as the basic process, and the product as basic iron or steel. The process gives rise to a valuable by-product known as Thomas or phosphatic slag fertiliser.
Research Thomas-Gilchrist Process
Thorium is radioactive metal element of the tin group with the symbol Th. Thorium was discovered by Berzelius in 1828. It occurs principally in thorite and other rare minerals. It was formerly isolated by displacement by potassium fluothorate, and is a grey metallic powder. It burns brightly in oxygen.
Research Thorium
The three-colour process is a method of making prints in natural colours by photographic or mechanical printing. The term is more widely used in the latter sense, and is employed to denote printing by the half-tone process in three colours. The basis of the three-colour process is the making of three negatives through red, green and blue-violet filters from which three prints are then superimposed to produce the final natural print. In mechanical printing three printing plates are used impressions from each of which are printed successively in the respective ink on a printing machine.
Research Three-Colour Process
In engineering, a throttle or throttle valve, is a valve for regulating the supply of fuel - steam, gas, petrol etc - to an engine.
Research Throttle
In engineering, the throw is the distance between the axis of a crank-pin and the axis of the crank-shaft; or between the centre of the eccentric and the axis of the shaft on which it is mounted. The throw of an engine crank is one-half the travel of the piston that drives it; that of an eccentric one-half the travel of the back-end of the eccentric rod.
Research Throw
Thulium is a rare metal element with the symbol Tm. Thulium was first discovered in 1879, but was not isolated until 1900. It is found in euxenite, samarskite, ytterspar and some other minerals.
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Thunder is a loud noise which accompanies lightning, but appears to follow it due to the difference at which sound and light travel. Thunder is the noise which occurs due to the disruption of the air by the electrical discharge (lightning), which at five times the heat of the sun actually causes the air to explode.
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Thymol (methyl-propylphenol) is a white crystalline phenol obtained from the oil of thyme, particulary Thymis vulgaris, and also from the oils of horsemint and ajowan. It has a pleasant aromatic smell and is used as an antiseptic and deodorant. Thymol is a strong antiseptic and has the advantage over phenol that it doesn't burn the skin.
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TIFF (Tag Image File Format) is a now dated format of bitmap image file developed by the Aldus Corporation for data exchange between desktop publishing and related computer applications, notably high quality exchange between the displayed and printed pictures.
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Time are an English PC assembler and retailer. They were established during the 1980s and have grown into a nationwide organisation with showrooms over the whole country. They assemble and supply a range of standard PCs aimed at the retail market.
Research Time
Timeslips Plus is a computer program designed to keep track of billable time. It is ideal for law offices or consultants, or for Information Centres that use a charge-back system. Timeslips Plus can be run memory-resident so you can access it while running other applications. When you begin a billable task such as a client phone call, call up a time slip and start the timer. When you stop the timer, you see how much time has elapsed. (If you prefer, you can input time manually without using the automatic timer.) Timeslips Plus also prepares professional-looking invoices in minutes which can be easily customised. The product lets you determine what information appears on the invoice and how it will be presented. Options include Bill, No Charge, Do Not Bill, Summary, and Work in Process. In addition, you can set minimum, maximum, or absolute fees for a project or case, no matter how many bills are sent. You can customise bills for each client to show as much detail as appropriate. The product lets you create expense slips for out-of-pocket expenses. Through a menu-driven
interface, Timeslips Plus allows you to print a report that evaluates performance based on the variance between actual and estimated time. Many other business and financial reports can be generated, along with more than 30 graphs and charts. Timeslips Plus can be customised to your particular application needs. Main headings default to User, Account, and Activity, but you can rename them as desired. The product can accommodate up to 250 individual users, 250 billable activities, and up to 3,400 accounts.
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Tin is a silver-white coloured, lustrous metal element with the symbol Sn. It occurs commonly in the ore cassiterite, which is found in Malaysia, Indonesia, Bolivia, the Democratic Republic of the Congo (Zaire), Nigeria and Cornwall. Tin is highly ductile and malleable, takes a high polish, is a poor conductor of electricity and is not easily acted upon by the air leading to it often being used to plate iron to protect it from rusting.
Tin is widely used in the manufacture of tin plate, Britannia Metal, bronze, gun-metal and pewter. Heated in air tin combines with oxygen to form tin oxide, a white insoluble powder, used under the name of putty powder for polishing purposes.
Research Tin
Tin-plate is a sheet of wrought iron or mild steel that has received a thin coating of two or three percent of tin by immersion in the molten metal to protect it from rust. Tin-plate is used in cans for food and drink. Tin-plate was first manufactured in great Britain around 1670 having been invented in Bohemia early in the 16th century.
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Tint is what is produced when a colour is lightened or reduced by the addition of white.
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Titanium is a metal element with the symbol Ti.
Research Titanium
Titanium dioxide (also known as titanium white) is a substance used as a very strong white pigment produced from the mineral limonite. It is a brilliantly pure white with enormous staining strength. Titanium dioxide is chemically inert and does not react with oil or varnish media of high acidic value and is resistant to chemicals in the atmosphere.
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Titration is the analysis or determination of the concentration of a solution by adding measured amounts of a standard solution of a suitable reagent until the chemical reaction between the two solutions is completed.
Research Titration
Toluene (methyl-benzene) is a colourless liquid derived from petroleum and coal-tar.
Research Toluene
Toluidine (Methyl-aniline) is a colourless, oily, fluid substance prepared from nitrotoluene. There are three isometric toluidines, the ortho-, meta- and para-toluidine, the orthotoluidine being the most important. Orthotoluidine differ from the other toluidines in giving a green colour with ferric chloride and paradiamidobenzene. Paratoluidine is a solid. The toluidines are employed in the manufacture of aniline dyes.
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Tombac, also known as Muntz metal and patent metal, is a full yellow coloured metal alloy. It is a kind of brass containing 60% copper and 40% zinc invented in 1832 by G F Muntz.
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In colour, tone is the amount of light reflected from a surface of colour, irrespective of all other characteristics.
Research Tone
The tonka bean is the fruit of a Guiana shrub. It is used in perfumery.
Research Tonka Bean
A tonometer is a contrivance for the exact measurement of musical pitch. The original tonometer, invented by Scheibler, consisted of 52 tuning forks laboriously corrected by counting the beats and by comparison with the results obtained from the monochord, so as to provide an accurately tuned scale from any given pitch.
Research Tonometer
Topography is the art or science of geographical description. That is giving the situation, natural features, buildings etc of a country and also describing the rivers, mountains etc.
Research Topography
TOPS-10 was DEC's proprietary OS for the fabled PDP-10 computer, long a favourite of hackers but now effectively extinct.
Research TOPS-10
In mechanics, torsion is the strain produced in a solid body when parallel planes are turned relatively to one another round an axis perpendicular to them. If one end of a cylindrical wire is kept fixed and the other end is twisted by a mechanical force, and if under this twisting stress the wire turns through an angle, then it is found that, so long as the angle is not too great, it is proportional to the applied force, that is if the applied force or couple is doubled, the angle through which the end of the wire is twisted is also doubled.
If the length and radius of the wire are known, and also the strength of the twisting force, then the angle through which the wire twists varies directly with the length of the wire multiplied by a constant depending upon the material of the wire. Since the angle varies inversely as the fourth power of the radius of the wire, the deflection produced by the twisting force increases very rapidly as the wire becomes smaller, for example if the wire's radius is halved the angle of twist is multiplied by 2 to the power of 4, or in other words 16. In measuring small torsions, therefore, a very thin wire or thread is chosen, and for this purpose quartz fibres of extreme tenuity are employed.
Most substances behave very differently in their ability to recover from torsion. Quartz, steel, glass etc will suffer a considerable torsion and when it is removed regain their original forms. Copper and lead on the other hand, will not recover from even small twists.
One of the important applications of torsion is in a spring, and it is because of its ability to recover that steel is typically used for springs.
Research Torsion
A torsion balance is an instrument which was invented by Coulomb for measuring electric and magnetic attraction. A fine silver wire supports, at its centre of gravity, a horizontal carrier with bodies of known electric charge at each end, or a magnet of known strength. The deflection of the carrier determines the strength of the attractive force when the source of attraction is placed at a known distance from it.
Research Torsion Balance
A touchstone is a device for roughly ascertaining the purity of gold alloys. It consists of a smooth strip of hard black stone, on which a corner of the alloy is rubbed so as to leave a streak, which is then moistened with an acid composed of 78.4% nitric acid, 1.6% hydrochloric acid and 20% water. By comparing the effect with that produced on streaks made with alloys of known compositions, an approximation to the gold content of the alloy is found.
Research Touchstone
Traceroute is a computer program for the Unix platform that attempts to trace the route an IP packet would follow to some Internet host. It traces the route by launching UDP probe packets with a small time to live (ttl) and then waiting for an ICMP 'time exceeded' reply from a gateway.
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A tractor is a power-driven machine adapted to haul other machines or vehicles over roads or rough ground.
Research Tractor
A tractrix is a curve whose tangents are all of equal lengths, the involute of a catenary.
Research Tractrix
Tragacanth gum is a partly water-soluble gum exuded by the tree Astragalus verus and used as an adhesive and in medicine for the preparation of emulsions.
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A transceiver is a combined radio transmitter and receiver sharing a common housing and many of the same components.
Research Transceiver
A transducer is a device which takes in power from one part of a system and emits power of a different kind to another part.
Research Transducer
A transformer is a device used for converting an alternating electric current from one voltage to another, depending upon electro-magnetic induction. The first transformer was made by Faraday in 1831.
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A transistor is an electronic component made of a semiconductor material and three or more electrodes.
Research Transistor
In astronomy, a transit circle is an instrument for ascertaining the time of star transits across the meridian. The transit cirlce was invented by Olaus Romer in 1690, and consists essentially of a telescope movable in the plane of the meridian, and supported on two pillars which are respectively east and west of it. On one side of the telescope is a fixed circle which denotes its movement in the plane of the meridian, and which is read by miscrosopes fixed to one of the supporting pillars. On the other side of the telescope is a circle which is used for moving it.
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In radio terms, a translator is a device that receives multiple signals within a certain frequency range and simultaneously retransmits them in another frequency range.
Research Translator
If a steel poker is pushed into the fire and left there for a time the handle becomes warm. Heat travels through the metal by a process called conduction. This process is complex. It differs between metals and non-metals. When a metal is heated the free electrons which it contains begin to move faster, i.e., their kinetic energy increases. The hot electrons then drift towards the cooler parts of the metal and at the same time there is a drift of slower-moving (cooler) electrons in the reverse direction. In those substances where no free electrons are present the process of conduction is entirely different. In such cases the heat energy is conveyed by longitudinal waves, similar to sound waves, but of considerably higher frequency. These waves are transmitted in tiny energy packets called 'phonons'. Most metals are good conductors of heat; silver and copper are exceptionally good. On the other hand, substances such as cork, wood, cotton and wool are bad conductors. Both good and bad conductors have their uses.
The best kettles, other than electric kettles, are made of copper, since heat is conducted most rapidly through this metal. The 'bit' of a soldering iron is also made of copper, so that when its tip is cooled through contact with the work, heat is rapidly conducted from the body of the bit to restore the temperature of the tip and maintain it above the melting point of solder. Bad conductors have a very wide application. Beginning with our personal comfort, we prevent loss of heat from ourselves by a covering of poorly conducting material. Textiles are bad conductors of heat, since they are full of tiny pockets of air enclosed by the fibres of the material. Air, in common with all gases, is a very bad conductor of heat. It is usual to say that wool is warmer than cotton. Technically, of course, we imply that it has a lower thermal conductivity than cotton. A stone floor feels cold to the bare feet, but a carpet on the same floor feels warm. This difference arises from the fact that stone is a better conductor of heat than a carpet. To begin with both the stone floor and the
carpet are at the same temperature. Since the feet are warmer than either, heat tends to flow from the feet. Stone, being the better conductor, conveys heat away from the feet more rapidly than the carpet. Consequently, the feet feel cold on the stone but warm on the carpet. Precisely the same effect is experienced when handling a garden fork in winter. The iron part of the fork feels cold, but the wooden handle warm.
Loss of heat by conduction through the walls of an oven is reduced by constructing it with double walls. The space between is packed with slag wool or glass fibre. These substances are not only very poor conductors but also have the merit of being non-inflammable. Material of low thermal conductivity used for the purpose of preventing heat loss is called lagging. Another example is the covering of hot-water storage tanks and pipes with a layer of plaster mixed with asbestos or other insulating material. Similarly, cold-water pipes may be lagged with strips of felt or sacking to prevent freezing during very cold weather.
Research Transmission of Heat
A transponder is a device that will emit a radio signal when it receives a radio signal on a certain frequency.
Research Transponder
Transuranic is a chemical term referring to artificially manufactured elements which have an atomic number higher than uranium.
Research Transuranic
A transverter is a device that takes one radio signal in a specified frequency range and simultaneously retransmits it in another frequency range. (This differs from a translator, which can handle more than one signal).
Research Transverter
A treadle is a foot operated lever used to impart motion to a machine, such as a sewing machine or lathe for example.
Research Treadle
A treadmill crane was a simple, but ingenious device used for hoisting large blocks of stone up to great heights when building castles and cathedrals etc during the Mediaeval period and beyond to the 18th century, throughout Europe. The treadmill crane comprised a large wooden cylinder, open at one side, about 210 cm in diameter with a stout wooden spindle in the centre. This cylinder was mounted at the top of the structure being built, and turned by two or three men walking the treadmill, which caused the spindle to rotate. Fixed to the spindle was a stout rope which was turned on to the spindle by the rotation, and so hoisted up what ever was attached at the lower end. By using treadmill cranes, Mediaeval builders in the 13th century were able to hoist blocks of stone weighing two tons and more to the great heights of Salisbury Cathedral spire and the great castles of England.
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A triac is a bi-directional thyristor used in A.C. control circuitry.
Research Triac
In geometry, a triangle is any figure formed by three intersecting lines. When the lines are straight the triangle is a plane triangle. In spherical triangles, the sides are arcs of great circles of a sphere. Triangles are called equilateral, isoceles and scalene, according as all three sides are equal, two sides are equal, or all sides are unequal. The first book of Euclid is concerned chiefly with the properties of plane triangles, and from the study of such properties arose the science of trigonometry. The area of a plane triangle is half the length of the base multiplied by the altitude of the apex or the square root of s(s-a)(s-b)(s-c) where a,b and c are the lengths of the sides, and s is half their sum.
Research Triangle
Triangulation is a technique employed in surveying. A base-line is set out in a convenient and level situation and measured with great accuracy. A theodolite is then set up at each end of the base- line, and readings are taken on some prominent point or beacon, giving the angular displacement of the beacon relative to the base-line. A triangle is thus formed, of which the size of the angles and the length of one side are known, and therefore the length of the remaining sides may be calculated.
Research Triangulation
1,1,2-Trichloroethane is a colourless, sweet-smelling man-made liquid that is predominantly used where 1,1-dichloroethane (vinylidene chloride) is manufactured. It may also be formed in landfills when 1,1,2,2-tetrachloroethane is broken down. 1,1,2-Trichloroethane is used as a solvent where its high solvency is needed, such as for chlorinated rubbers. It may be used as a solvent for fats, oils, waxes, and resins. 1,1,2-Trichloroethane may be found in some consumer products. 1,1,2-Trichloroethane will not burn and has a higher boiling point than water. When it is released into the environment, it eventually ends up in the atmosphere or groundwater. Reaction in both the atmosphere and groundwater is very slow. In the air, half of the chemical is expected to degrade in 49 days and will disperse far from where it is released before degrading. There is no breakdown of 1,1,2-trichloroethane below the soil surface in groundwater within 16 weeks; some experiments suggest that it will persist for years. 1,1,2-Trichloroethane is soluble in alcohol, ether, and chloroform.
1, 1,2-trichloroethane is also known as ethane trichloride; trichloroethane; vinyl trichloride; and 1,2,-trichloriethane.
Research Trichloroethane
Trichloroethylene is a colourless liquid at room temperature with an odour similar to ether or chloroform. It is a man-made chemical that does not occur naturally in the environment.
Trichloroethylene is a powerful chlorinated solvent mainly used as a solvent to remove grease from metal parts - commonly prior to painting. It is used as a solvent in other ways, too, and is used as a chemical building block to make other chemicals.
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A tridecagon is a thirteen-sided polygon.
Research Tridecagon
Triethanolamine is normally used as an auxiliary emulsifying agent after in situ reaction with a fatty acid in the preparation of cosmetic emulsion products such as creams and lotions. It has several disadvantages not least that of discolouring easily in the presence of trace metal contaminants and even on simple exposure to air.
Research Triethanolamine
Trimethylamine is a tertiary amine, that occurs in herring brine and the blossoms of hawthorn. It is chiefly obtained as a product of the distillation of the nitrogenous residue left in the preparation of sugar from beetroot. It is a gas with a fishy ammonia-like odour and a strong alkaline reaction. When heated with hydrogen chloride it yields methyl chloride. It is used for preparing pure potassium carbonate from potassium chloride and has also been used in medicine as a cure for gout and rheumatism.
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In chemistry, a trinitrate is a compound formed from three molecules of nitric acid by the replacement of the 3 hydrogen atoms by a trivalent element or radical.
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Trinitrotoluene (TNT) is a high explosive.
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The Trio TS711E was a Japanese two-meter amateur radio scanning transceiver designed for the British market and introduced in 1984. The Trio TS711E covered the 144 Mhz to 146 Mhz amateur band in FM, USB, LSB and CW modes, and had a 40 channel memory.
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A triode is an electronic amplifying valve with three main electrodes (anode, cathode and grid).
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In chemistry, a trioxide is a compound with three atoms of oxygen with an element or radical.
Research Trioxide
Tritium is an unstable isotope of hydrogen. Tritium is radioactive, but considered safer than radium as it is thought that the rays emitted by tritium are unable to penetrate the outer layer of skin on human tissue, or even a thin layer of glass. Tritium replaced radium in luminous paints used for watch dials and the like.
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A trocar is a surgical stylet with a triangular point enclosed in a metal tube and used for withdrawing fluid from a cavity.
Research Trocar
Troff is a UNIX formatting and phototypesetting program, written originally in PDP-11 assembler and then in barely-structured early C by the late Joseph Ossanna, modelled after the earlier ROFF which was in turn modelled after Multics' RUNOFF by Jerome Saltzer (that name came from the expression 'to run off a copy'). A companion program, 'nroff', formats output for terminals and line printers. In 1979, Brian Kernighan modified TROFF so that it could drive phototypesetters other than the Graphic Systems CAT. The success of TeX and desktop publishing systems have reduced troff's relative importance.
Research Troff
A trompe is a water blowing engine. It consists of a long vertical wooden pipe, the lower end of which runs into an air chest. At the top of the pipe is a cone-shaped plug through which water passes. Air enters through holes near the top end, and is forced down into the air chest under pressure by the falling water, the pressure being dependant upon the height of the fall and averaging about one pound per square inch for every two feet of fall. The trompe was a cheap method of working compressed-air engines and machinery in the vicinity of waterfalls. Trompes were chiefly used in America.
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Trona is a naturally occurring hydrous sodium carbonate found in north Africa and America.
Research Trona
Tropine (methyl-oxyethylpyridine tetrahydride) is an artificial alkaloid obtained by heating atropine or hyoscyamine with baryta-water.
Research Tropine
The troposphere is the layers of the atmosphere in which, up to a certain height, the temperature falls with increasing altitude.
Research Troposphere
Tropospheric ducting is the propagation of radio signals above 30 Mhz via bending and ducting along weather fronts in the lowest layer of the Earth's atmosphere, the troposphere.
Research Tropospheric Ducting
Trunking is a method of switching incoming radio signals between different repeater stations to prevent interference and ensure access to a repeater.
Research Trunking
Tube wells, popularly known as Norton's Abyssinian tube wells, were popular around 1900 as a means of collecting water. Tube wells were used when a temporary supply of water was required, and are superior to dug wells which are liable to become foul from surface pollutants.
A tube well is constructed by driving tubes into the soil, one length being screwed onto another, the first tube being perforated at the bottom for about 60 cm, its lower end being furnished with a steel point.
When the subsoil water is reached, a pump is attached to the tube; the water after pumping a short time is clear; the tube forms a cavity which corresponds to the ordinary well at the end of the pipe, owing to the removal of the soil by pumping.
As long ago as the end of the 19th century, the scientist Koch recommended that iron tubes be placed in dug wells and the surrounding space be filled in with cean gravel and sand, the water raised by a pump fixed at the surface.
Research Tube Well
Tuberculin was a substance prepared from cultures of the bacilli of tuberculosis. It was introduced by Koch in 1890 and was hoped it would provide a cure for tuberculosis. Results, however, were disappointing.
Research Tuberculin
Tung oil (also known as Kukrui oil and China wood oil) is an oil obtained from the seed pods of several varieties of the aleurites or tung tree native to China. Tung oil is pale amber in colour, dull, with an unpleasant smell and taste. It is one of the best drying oils and was used in quick-drying paints and marine varnishes.
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Tungsten (previously also known as wolfram and scheelium) is a grey-white, heavy, high-melting, ductile, hard, polyvalent metallic element that resembles chromium and molybdenum in most of it's properties and is used especially for electrical purposes and in hardening steel. It has the symbol W. Tungsten was first obtained in tungstic acid by Scheele in 1781 and extracted from tungstic acid in 1786 by the De Luyart brothers, and in 1859 was first employed commercially in the making of a new kind of steel.
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A tungsten lamp is an incandescent electric lamp in which the filament consists of tungsten. Usually a pure tungsten filament is used, but formerly a carbon core coated with tungsten was also used. Tungsten took over from carbon filaments veacsue tungsten has advantages over carbon filaments in giving more light for lower power consumption, being less affected by variations in voltage and remaining at the same candle power for longer than carbon filaments.
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A turbine is a type of engine. Steam turbines often propel ships and power stations. Gas turbines are also used.
Research Turbine
TurboCAD is a Computer-Aided Design (CAD) program by IMSI Limited for professionals and corporate design departments, but promising ownership costs similar to conventional Office applications such as spreadsheets and databases. The program includes features like extensive customising capabilities and hooks to external database programs. IMSI also hopes to capitalise on AutoCAD's widespread support industry, with a new programming interface which offers compatibility with AutoCAD add-ons.
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Turkey red is an artificial red oxide with high opacity, produced by calcining yellow iron oxide at a relatively low temperature. Turkey red is used in paint.
Research Turkey Red
Turkey umber is a type of umber obtained from Cyprus, but so called because it was originally exported through Turkey.
Research Turkey Umber
A turnbuckle is a coupling screwed at both ends, noe end having a right-hand and the other end having a left-hand thread, to which the ends of two bars are screwed. By turning the turnbuckle the screw threads enter further into the screwed sockets, and the bars are drawn nearer together. Turnbuckles are used for applying tension to steel-wire ropes and tie bars.
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Turnbull's Blue is a pigment produced by the action of a ferrous salt on potassium ferri-cyanide.
Research Turnbull's Blue
Turpentine is the resinous exudation of various coniferous plants. Turpentine is a valuable solvent, it is clear, limpid and colourless. It evaporates almost completely, leaving no visible residue when exposed in a thin film. Turpentine dissolves all vegetable and mineral oils, but does not dissolve the linoxyn formed by the drying of a paint film, and as such does not disturb previously applied coats of paint making it the ideal solvent for use in paints, though its use declined in preference to cheaper white spirit.
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Tutenag is an alloy of copper, nickel and zinc used at one time for domestic-ware and fire-grates.
Research Tutenag
Tuttle's Comet is a comet with an orbit of fourteen years. It was first recorded by Mechain in 1790, and shown to be periodic by Tuttle in 1858.
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A tuyere is a terminal of a pipe through which air is supplied to a furnace. It is usually in the shape of a truncated cone, with the smaller end euntering the furnace. Because tuyeres get very hot, and were traditionally made of cast iron, special provision had to be made to prevent it from being burnt or even melted. Tuyeres were made with a hollow wall having an inlet and outlet at the wide end, through which water was circulated to cool the device.
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A twaddell is a hydrometer for measuring the specific gravity of liquids heavier than water. The twaddell was invented by, and named after, the Scottish scientist Twaddell.
Research Twaddell
Twenex was the TOPS-20 operating system by DEC - the second proprietary OS for the PDP-10. TOPS-20 began in 1969 as Bolt, Beranek & Newman's TENEX operating system using special paging hardware. By the early 1970s, almost all of the systems on the ARPANET ran TENEX. DEC purchased the rights to TENEX from BBN and began work to make it their own. The first in-house code name for the operating system was VIROS; when customers started asking questions, the name was changed to SNARK so DEC could truthfully deny that there was any project called VIROS. When the name SNARK became known, the name was briefly reversed to become KRANS; this was quickly abandoned when someone objected that `krans' meant `funeral wreath' in Swedish (though some Swedish speakers have since said it means simply `wreath'; this part of the story may be apocryphal). Ultimately DEC picked TOPS-20 as the name of the operating system, and it was as TOPS-20 that it was marketed. The hacker community, mindful of its origins, quickly dubbed it TWENEX (a contraction of `twenty
TENEX'), even though by this point very little of the original TENEX code remained (analogously to the differences between AT&T V6 UNIX and BSD). DEC people cringed when they heard 'TWENEX', but the term caught on nevertheless (the written abbreviation ` 20x' was also used). TWENEX was successful and very popular; in fact, there was a period in the early 1980s when it commanded as fervent a culture of partisans as UNIX or ITS but DEC's decision to scrap all the internal rivals to the VAX architecture and its relatively stodgy VMS OS killed the DEC-20 and put a sad end to TWENEX's brief day in the sun. DEC attempted to convince TOPS-20 hackers to convert to VMS, but instead, by the late 1980s, most of the TOPS-20 hackers had migrated to UNIX.
Research Twenex
The Tyndall Effect is the scattering of light by fine suspended particles. If a beam of white light is passed through a colloidal suspension of a substance such as mastic in water, light will be emitted at right angles to the beam.
Research Tyndall Effect
Type metal was an alloy used for type-casting, that is casting the type used for printing. Type metal was usually a mixture of lead and antimony - the antimony added to give hardness - sometimes with the addition of tin, nickel, copper or bismuth.
Research Type Metal
In printing, a typeface is a design of the characters. Popular typefaces are 'Times', 'Arial' and 'Verdana'. The term 'font' is often erroneously used in computing circles to describe a typeface.
Research Typeface
In computer terms, the typematic rate is how fast keys repeat when held down.
Research Typematic Rate
In computer terms, the typematic rate delay is the initial delay before key auto-repeat starts. That is how long you've got to press a key before it starts repeating.
Research Typematic Rate Delay
The typewriter is a machine for printing letters singly on paper which is traversed and moved forward so as to allow writing to be performed. The first patent for a typewriter was filed in 1714 by the Englishman Henry Mills, but the first practical typewriter wasn't invented until 1843 by Charles Thurber. The modern typewriter owes much to the machines produced by Charles Latham Sholes which were adopted by the Remington and Son company of New York, their first machine going on sale in 1874. By the end of the 20th century the typewriter was obsolete, replaced by computerised word processing applications.
Remington's typewriter sold in 1874 had the type-bars pivoted about a horizontal ring, the arms of the type-bars being connected by vertical rods to the levers leading to the keyboard. A rubber cylinder moved the paper, and the impression of the type was supplied by an inked ribbon which unwound automatically from a spool. The pressing down and release of each key in turn moved the paper-carrying cylinder along one space by means of a spring. The roller was moved back and turned ready for the following line by hand. In the original machine each type-bar carried only one character, but later two were introduced on each, and in later machines still three. A shift key enabled any set of characters required to come into operation. By thus economy of keys one set was enabled to print capital and small letters, figures and certain standard punctuation marks, etc. without unduly enlarging the keyboard.
The Remington typewriter was followed by others embodying various new ideas and improvements. The keyboard became standardised, and various standard improvements were introduced such as a back spacing key which enabled the carriage to be reversed one space as necessary to retype a letter; two and three colour ribbons, etc.
Some early typewriters used an ink-pad, the type-bar being pressed against the ink pad before being brought into contact with the paper, but by the later 20th century these were extinct and all typewriters, whether manual or electric were using an inked ribbon.
Quite early some typewriters had their characters arranged on the circumference of a small wheel or small cylinder, which were automatically rotated as the type-key was depressed. Some later typewriters had their characters arranged around a small ball. Many typewriters had the capacity for the entire set of type-bars or type wheel to be interchanged, allowing different sets of characters to be printed.
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Typographic etching was a process invented by the Dawson brothers of Chiswick, about 1863, to produce a metal block by means of an electro or cast of the actual lines of a drawing. At first the process was used for landscape, architecture, figures, etc. The introduction of photo-zincography and halftone gradually superseded typographic etching which after 1890 was confined almost exclusively to producing maps, plans etc, before finally becoming obsolete.
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A tyre or tire is a hoop, band, or air-filled tube on the rim of a wheel. The steel tyre of a wooden carriage or cart wheel binds the felloes and spokes tightly together, and takes the wear of usage. The tyre is made rather smaller in the first instance, is expanded by heat until it will pass over the felloes, and is allowed to cool, contracting and holding fast. The former rolled steel tyres of railway locomotive carriages and cars were shrunk onto the cast iron or steel centre in a similar way. A projecting lip on the outer face and a ring forced into a groove at the other side, made it impossible for the tyre to move laterally should the shrinkage grip prove insufficient. Railway tyres were about 13 cm broad, at least 2.5 cm thick, and were made of the best steel. The tread was coned to an angle of 1 in 32 towards the outside edge. Flanges were 2.5 cm deep and 2.5 cm wide.
The invention of the bicycle led to the invention of solid rubber tyres which were also used for light carts and heavy automobiles. The tyre was held on the rim by a wire or wires embedded in it, or by beads engaging with flanges in the rim.
The pneumatic tyre became universal by about 1920 and appears to have been invented in 1846 by T Thomson, but credit for the first practical use of the idea is given to J B Dunlop who in 1888 fitted a bicycle with a crude form of air-inflated tyre.
The early pneumatic tyre consisted of two separate parts - an inner air tube of rubber; and an external cover of cotton threads embedded in rubber, and faced with a thick coating of rubber, sometimes protected by steel studs. Rubber treads are corrugated transversely or circumferentially, or in both directions, to minimise slip and skidding. Modern pneumatic tyres, particularly those used on motor cars are without an inner-tube.
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Tyrian dye was a purple dye derived from animal juice in the shell-fish murex. It was used in ancient times. Since only small quantities could be obtained, it's use was limited to the great and the wealthy, hence purple became the colour associated with majesty.
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