A History of Everyday Technology in 68 Quiz Questions

Question: In 1877 Thomas Alva Edison made indentations in a strip of coated paper with a stylus connected to a transmitter. When he pulled the strip back through the apparatus, he was astonished to hear that it produced a sound. What had he just invented?

Answer: In 1877 Thomas Alva Edison achieved his most original discovery, the phonograph. Some earlier researchers had theorized that each sound, if it could be graphically recorded, would produce a distinct shape resembling shorthand, or phonography (“sound writing”), as it was then known. Edison hoped to reify this concept by employing a stylus-tipped carbon transmitter to make impressions on a strip of paraffined paper. To his astonishment, the scarcely visible indentations generated a vague reproduction of sound when the paper was pulled back beneath the stylus. Edison unveiled the tinfoil phonograph, which replaced the strip of paper with a cylinder wrapped in tinfoil, in December 1877.

Question: On February 14, 1876, American inventor Elisha Gray arrived at the U.S. Patent Office only hours after his competitor, losing his claim to an epoch-making invention. What was it?

Answer: In the 1870s two American inventors, Elisha Gray and Alexander Graham Bell, both independently designed devices that could transmit speech electrically. An application for a U.S. patent on Bell’s work was filed on February 14, 1876. Several hours later that same day, Gray filed a caveat on the concept of a telephone transmitter and receiver.

Question: The first one caught fire, the second one now resides at Lake Havasu, Arizona, and the third one still connects a city centre with the borough of Southwark. What are they?

Answer: The name London Bridge refers to any of several successive structures spanning the River Thames between Borough High Street in Southwark and King William Street in the City of London. The Old London Bridge was completed by 1209. Almost immediately the bridge became not only an important commercial crossing but also a choice business and residential site. Three years after its completion, a fire destroyed all the buildings and killed as many as 3,000 people. Finally the maintenance became too much of a burden, and the City asked the renowned engineer John Rennie to design a wholly new structure several yards upstream. In 1831 King William IV and Queen Adelaide arrived by water to celebrate the opening of the new bridge. Between 1968 and 1971 its facing stone was dismantled and shipped across the Atlantic Ocean to the U.S. state of Arizona, where it was reerected on Lake Havasu. The third London Bridge was built between 1968 and 1972.

Question: Igor Sikorsky is best known for his successful development of which of these vehicles?

Answer: In March 1919 Igor Sikorsky landed in New York as an immigrant. After several lean years he and a few associates formed the Sikorsky Aero Engineering Corporation. Early in 1939, with a well-trained engineering group at his disposal, he started construction of the VS-300 helicopter. On September 14, 1939, the VS-300 lifted off the ground on its first flight.

Question: Who invented wireless telegraphy?

Answer: Guglielmo Marconi investigated electromagnetic wave technique. After he went to London in 1896, he was able to send signals over distances up to 6.4 km (4 miles) on the Salisbury Plain and to nearly 14.5 km (9 miles) across the Bristol Channel. Marconi’s cousin Jameson Davis, a practicing engineer, financed his patent and helped in the formation of the Wireless Telegraph and Signal Company, Ltd., which provided support for Marconi’s new communication technology: wireless telegraphy, otherwise known as radio.

Question: The clepsydra was an ancient device that allowed water to flow or drip from a vessel, with the escaping or remaining water being marked against a scale. What did this device measure?

Answer: Also called the water clock, the clepsydra was an ancient device for measuring time by the gradual flow of water.

Question: Cornelis Drebbel’s invention, built of wood and greased leather and propelled by oars, was the first of which type of boat?

Answer: Cornelis Drebbel, a Dutch inventor, is usually credited with building the first submarine. Between 1620 and 1624 he successfully maneuvered his craft at depths of 4 to 5 metres (12 to 15 feet) beneath the surface of the River Thames during repeated trials in England. Drebbel's outer hull consisted of greased leather over a wooden frame; oars extended through the sides and, sealed with tight-fitting leather flaps, provided a means of propulsion both on the surface and underwater.

Question: How was the message “What hath God wrought!” sent from Washington, D.C., to Baltimore, Maryland, on May 24, 1844?

Answer: In 1843 Samuel F.B. Morse obtained financial support from the U.S. government to build a demonstration telegraph system 60 km (35 miles) long between Washington, D.C., and Baltimore, Maryland. Wires were attached by glass insulators to poles alongside a railroad. The system was completed and public use initiated on May 24, 1844, with transmission of the message “What hath God wrought!”

Question: What did Dutch physicist Pieter van Musschenbroek invent in 1745 when he partly filled a glass vial with water, pushed a wire through the cork and into the water, and connected the wire to a friction device that produced static electricity?

Answer: In 1745 a cheap and convenient source of electric sparks was invented by Pieter van Musschenbroek, a physicist and mathematician in Leiden, Netherlands. Later called the Leyden jar, it was the first device that could store large amounts of electric charge. The Leyden jar devised by Musschenbroek consisted of a glass vial that was partially filled with water and contained a thick conducting wire capable of storing a substantial amount of charge. One end of this wire protruded through the cork that sealed the opening of the vial. The Leyden jar was charged by bringing this exposed end of the conducting wire into contact with a friction device that generated static electricity.

Question: What did Alfred Nobel invent?

Answer: By chance, Alfred Nobel discovered that nitroglycerin was absorbed to dryness by kieselguhr, a porous siliceous earth, and the resulting mixture was much safer to use and easier to handle than nitroglycerin alone. Nobel named the new product dynamite (from Greek dynamis, “power”) and was granted patents for it in Great Britain (1867) and the United States (1868). Dynamite established Nobel’s fame worldwide and made him a wealthy man.

Question: When the ancient Romans built an arch for a bridge, aqueduct, or monument, what last piece did they insert to lock the structure in place?

Answer: Arch construction depends essentially on the wedge. If a series of wedge-shaped blocks (i.e., ones in which the upper edge is wider than the lower edge) are set flank to flank, the result is an arch. These blocks are called voussoirs. The central voussoir is called the keystone. During construction of an arch, the voussoirs require support from below until the keystone has been set in place. The ancient Romans used the arch in bridges, aqueducts, and large-scale architecture.

Question: What device, perfected by László Bíró in the 1930s, features a steel ball rotating freely in a socket?

Answer: László Bíró, a Hungarian living in Argentina, patented the first satisfactory model of the ballpoint pen. His ballpoint pen, commonly called the “biro,” became popular in Great Britain during the late 1930s, and by the mid-1940s pens of this type were widely used throughout much of the world. The writing tip of a ballpoint pen consists of a metal ball, housed in a socket, that rotates freely and rolls quick-drying ink onto the writing surface.

Question: Who founded Tesla Motors?

Answer: Tesla Motors was founded by Martin Eberhard and Marc Tarpenning in 2003. Elon Musk was an early funder and became chairman in 2004. The company changed its name to Tesla, Inc., in 2017.

Question: In 1801 Johann Wilhelm Ritter discovered that silver chloride was darkened quickly by what invisible radiation present in sunlight?

Answer: The German physicist Johann Wilhelm Ritter, having learned of the discovery of infrared waves, looked beyond the violet end of the visible spectrum of solar radiation and found (in 1801) that there exist invisible rays that darken silver chloride even more efficiently than visible light. This spectral region extending between visible light and X rays is designated ultraviolet.

Question: What was launched into Earth orbit in 1990, was repaired by space-walking astronauts, and went on to generate spectacular images that contributed significantly to space science?

Answer: The Hubble Space Telescope (HST), the most sophisticated optical observatory of its era, was placed into orbit above the Earth by the crew of the space shuttle Discovery on April 25, 1990. On December 2–13, 1993, a mission of the NASA space shuttle Endeavour sought to correct the telescope’s optical system and other problems. The HST soon began returning spectacular photographs of various cosmic phenomena.

Question: Beginning in 1994, which American software company offered a simple point-and-click interface for browsing the Internet?

Answer: In April 1994 Mosaic Communications Corp.—which would later become Netscape Communications Corp.—offered a graphical interface to replace line commands over the Internet. With the ability to display colourful graphics and a simple point-and-click interface for finding, viewing, and downloading data over the Web, the free Mosaic software made the Internet widely accessible for the first time beyond the scientific branches of academia and the government where it started.

Question: What were early seamen preparing to measure when they tied knots every 47 feet on a rope?

Answer: In navigation, the knot is a measure of speed at sea, equal to one nautical mile per hour. The term knot probably results from its former use as a length measure on ships’ log lines, which were used to measure the speed of a ship through the water. Such a line was marked off at intervals by knots tied in the rope. Each interval, or knot, was about 47 feet (14.3 metres) long. When the log was tossed overboard, it remained more or less stationary while its attached log line trailed out from the vessel as the latter moved forward. After 28 seconds had elapsed, the number of knots that had passed overboard was counted. The number of knots that ran out in 28 seconds was roughly the speed of the ship in nautical miles per hour.

Question: Which device did James Watt improve in 1765 by adding a separate condensor?

Answer: While repairing a Newcomen steam engine in 1764, James Watt noted its waste of steam. In May 1765, after wrestling with the problem of improving it, he suddenly came upon a solution—the separate condenser, his first and greatest invention.

Question: For what invention did Emperor Napoleon I make Alessandro Giuseppe Antonio Anastasio Volta a count and senator?

Answer: In 1780 Alessandro Volta’s friend Luigi Galvani discovered that contact of two different metals with the muscle of a frog resulted in the generation of an electric current. Volta began experimenting in 1794 with metals alone and found that animal tissue was not needed to produce a current. This finding provoked much controversy between the animal-electricity adherents and the metallic-electricity advocates, but, with his demonstration of the first electric battery in 1800, victory was assured for Volta. In 1801 in Paris, he gave a demonstration of his battery’s generation of electric current before Napoleon, who made Volta a count and senator of the kingdom of Lombardy.

Question: What was Peter Peregrinus of Maricourt, a 13th-century French Crusader, referring to when he described the properties of the lodestone in a letter to a soldier named Sygerus of Foucaucourt?

Answer: A French Crusader and scholar, Peter Peregrinus (“Peter the Pilgrim”) of Maricourt wrote a letter about magnetism while serving as an engineer in the army of Charles I of Anjou that was besieging Lucera (in Italy) in August 1269. The first part of the letter treats the properties of the lodestone (magnetite, a magnetic iron oxide mineral), and the second part describes several instruments that utilize the properties of magnets.

Question: What did the 18th-century Scottish millwright Andrew Meikle invent when he constructed a strong drum with fixed beaters that may have been copied from machines used to beat the fibres from flax plants?

Answer: . In 1778 Andrew Meikle constructed his first threshing machine. The machine was a failure, as was a second, developed from a Northumberland model.

Question: What is the popular name for a compression-ignition engine, in which fuel is ignited without introduction of a spark?

Answer: The diesel engine gains its energy by burning fuel injected or sprayed into the compressed, hot air charge within the cylinder. Diesel engines are sometimes called compression-ignition engines because initiation of combustion relies on air heated by compression rather than on an electric spark.

Question: What is the common name for polyhexamethylene adipamide, the first wholly synthetic fibre ever produced?

Answer: In October 1938, DuPont announced the invention of the first wholly synthetic fibre ever produced. Given the trade name Nylon (which has now become a generic term, nylon), the material was actually polyhexamethylene adipamide, first synthesized at DuPont in 1935 by Wallace Hume Carothers.

Question: What versatile, easily worked synthetic resin is made into permanent-press fabrics, soft-drink bottles, and party balloons and is among the most widely recycled plastics?

Answer: Polyethylene terephthalate (PET) is made into a high-strength textile fibre marketed under various trade names. The stiffness of PET fibres makes them highly resistant to deformation, so that they impart excellent resistance to wrinkling in fabrics. Molten PET can be blow-molded into a transparent container of high strength and rigidity that also possesses good impermeability to gas and liquid. In this form PET has become widely used in carbonated-beverage bottles and in jars for food processed at low temperatures. It is among the most widely recycled plastics.

Question: Soldering wire, widely employed in connecting electrical leads, is almost always made of which pair of metals?

Answer: The most common solders are basically alloys of lead and tin. Most solders contain 30 to 70 percent tin, with occasional minor additions for special purposes. The major application of solders is in production of electrical connections in the electrical and electronics industries.

Question: Who invented the pendulum clock?

Answer: The Dutch mathematician and scientist Christiaan Huygens invented a clock controlled by the motion of a pendulum in 1656. The priority of invention of the pendulum clock has been ascribed to Galileo by some authorities and to Huygens by others, but Huygens solved the essential problem of making the period of a pendulum truly constant. He devised a pivot that caused the suspended body, or bob, to swing along the arc of a cycloid rather than that of a circle.

Question: What new structural material was introduced by French gardener Joseph Monier in the design of his flowerpots?

Answer: In 1867 a French gardener, Joseph Monier, patented a method of strengthening thin concrete flowerpots by embedding iron wire mesh into the concrete. Monier later applied his ideas to patents for buildings and bridges.

Question: Who invented the first commercially successful atmospheric steam engine?

Answer: Credit for the first commercially successful atmospheric steam engine traditionally goes to Thomas Newcomen, who erected his first machine near Dudley Castle in Staffordshire, England, in 1712. It operated by atmospheric pressure on the top face of a piston in a cylinder, in the lower part of which steam was condensed to create a partial vacuum.

Question: In 1906 Lee de Forest invented the Audion, a vacuum tube in which small voltage changes at one electrode produced large changes at another. What significant advance did the Audion immediately make possible?

Answer: The American inventor Lee de Forest in 1906 conceived the idea of interposing an open-meshed grid between a heated filament and positively biased anode, or plate, to control the flow of electrons. De Forest called his invention an Audion. With it he could obtain a large voltage change at the plate for a small voltage change on the grid electrode. This was a discovery of major importance because it made it possible to amplify the radio-frequency signal picked up by the antenna before application to the receiver detector; thus, much weaker signals could be utilized than had previously been possible.

Question: What was the name given by the Wright brothers to the unique method of controlling their aircraft in flight?

Answer: After considering various mechanical schemes for obtaining such control, the Wright brothers decided to try to induce a helical twist across the wings in either direction. The resulting increase in lift on one side and decrease on the other would enable the pilot to raise or lower either wing tip at will. Their first experiments with “wing warping,” as the system would be called, were made with a small biplane kite flown in Dayton, Ohio, in the summer of 1899.

Question: In the early 20th century, kitchen appliances and radios frequently came with knobs and other parts made from what new material?

Answer: Many people date the beginning of the modern plastics industry to 1907, when Leo Baekeland, a Belgian-born American chemist, applied for a patent on a phenol-formaldehyde thermoset that eventually became known by the trademarked name Bakelite. Because of its excellent insulating properties, the resin was made into sockets, knobs, and dials for radios and was used in the electrical systems of automobiles.

Question: What was the Peacemaker of 1873?

Answer: Samuel Colt’s firm produced the pistols most widely used during the American Civil War, and its six-shot, single-action .45-calibre Peacemaker model, introduced in 1873, became the most famous sidearm of the American West.

Question: What is the formal name for a lie detector?

Answer: The lie detector, formally called a polygraph, is an instrument for recording physiological phenomena such as blood pressure, pulse rate, and respiration of a human subject as that person answers questions from an operator; these data are then used as the basis for making a judgment as to whether or not the subject is lying.

Question: What did French engineer Alphonse Beau de Rochas anticipate in 1862 when he described the intake-compression-power-exhaust sequence?

Answer: A major theoretical advance occurred with the publication in 1862 of a description of the ideal operating cycle of an internal-combustion engine. The author, the French engineer Alphonse Beau de Rochas, described the required sequence of operations as (1) suction during an entire outstroke of the piston, (2) compression during the following instroke, (3) ignition of the charge at dead centre and expansion during the next outstroke (the power stroke), and (4) expulsion of the burned gases during the next instroke. The engine Beau de Rochas described thus had a four-stroke cycle.

Question: What was George and Robert Stephenson’s Rocket, which reached a speed of 58 km (36 miles) per hour in 1829?

Answer: On September 27, 1825, railroad transportation was born when the first public passenger train, pulled by George Stephenson’s Active (later renamed Locomotion), ran from Darlington to Stockton, carrying 450 persons at 24 km (15 miles) per hour. Liverpool and Manchester interests called him in to build a 64-km (40-mile) railroad line to connect the two cities. When the line was nearing completion in 1829, a competition was held for locomotives; Stephenson's new engine, the Rocket, which he built with his son, Robert, won with a speed of 58 km (36 miles) per hour.

Question: In petroleum refining, what name is given to the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and pressure?

Answer: In petroleum refining, cracking is the process by which heavy hydrocarbon molecules are broken up into lighter molecules by means of heat and usually pressure and sometimes catalysts.

Question: What invention, which soon had a profound effect on science, did Dutch spectacle maker Hans Lippershey present to the government of Holland in 1608?

Answer: Hans Lippershey, a Dutch spectacle maker, is traditionally credited with inventing the telescope (1608). On October 2, 1608, he formally offered his invention, which he called a kijker (“looker”), to the Estates of Holland for use in warfare. The potential importance of the instrument in astronomy was recognized by, among others, Jacques Bovedere of Paris; he reported the invention to Galileo, who promptly built his own telescope.

Question: Who invented the safety elevator?

Answer: In 1852 Elisha Otis designed and installed what he called the “safety hoist,” the first elevator equipped with an automatic safety device to prevent it from falling if the lifting chain or rope broke. The next year he set up a small elevator shop in Yonkers, selling his first elevator machine on September 20, 1853. It hauled freight. On March 23, 1857, he installed the first safety elevator for passenger service in the store of E.V. Haughwout & Co. in New York City.

Question: Which of these is used to capture solar energy and convert it into thermal energy?

Answer: Two main types of devices are used to capture solar energy and convert it to thermal energy: flat-plate collectors and concentrating collectors. Flat-plate collectors are commonly used for hot-water heating and house heating.

Question: What new type of transmitting system, patented by American electrical engineer Edwin H. Armstrong in 1933, eliminated static from radio reception?

Answer: In 1933 Edwin H. Armstrong secured four patents on advanced circuits that revealed an entirely new radio system, from transmitter to receiver. Instead of varying the amplitude, or power, of radio waves to carry voice or music, as in all radio before then, the new system varied, or modulated, the waves’ frequency (number of waves per second) over a wide band of frequencies. This created a carrier wave that natural static could not break into. As a result, the wide frequency range of frequency modulation, or FM, made possible the first clear, practical method of high-fidelity broadcasting.

Question: What is a thermocouple used for?

Answer: A thermocouple is a temperature-measuring device consisting of wires of two different metals joined at each end.

Question: What early vehicles were known as “boneshakers”?

Answer: The hard ride of wood-spoked wheels and iron rims gave early velocipedes the sobriquet of “boneshaker,” but solid rubber tires and wire-spoked wheels helped soften the ride. In 1870, just as the boneshaker was developing into a practical bicycle called the “ordinary,” the Franco-German War set back the French industry.

Question: Who created the first thermometer?

Answer: The invention of the thermometer is generally credited to Galileo. In his instrument, built about 1592, the changing temperature of an inverted glass vessel produced the expansion or contraction of the air within it, which in turn changed the level of the liquid with which the vessel’s long, openmouthed neck was partially filled.

Question: What technology can be traced to the early 19th century, when Nicéphore Niépce practiced “heliography” with paper, silver salts, and pewter?

Answer: In 1813 Nicéphore Niépce sought a way to provide images automatically. He coated pewter with various light-sensitive substances in an effort to copy superimposed engravings in sunlight. From this he progressed in April 1816 to attempts at photography, which he called heliography (“sun drawing”), with a camera. He recorded a view from his workroom window on paper sensitized with silver chloride but was only partially able to fix the image. In 1826/27, using a camera, he made a view from his workroom on a pewter plate, this being the first permanently fixed image from nature.

Question: When did the first smartphone make its public debut?

Answer: The first smartphone made its public debut in 1993; it was designed by IBM and sold by BellSouth. Called IBM Simon, it is considered the first smartphone because of the manner in which it combined telephony, a touchscreen interface, and multiple functions familiar to smartphone users today.

Question: Early windmills transformed the kinetic energy of wind into what form of energy?

Answer: Windmills, like waterwheels, were among the original prime movers that replaced animal muscle as a source of power. They were used for centuries in various parts of the world, converting the energy of the wind into mechanical energy for grinding grain, pumping water, and draining lowland areas.

Question: Which great engineering project was begun in New York City in 1869 by John Roebling but had to be completed after his death by Emily Warren Roebling, his daughter-in-law?

Answer: John Roebling died in 1869, shortly after work began on the Brooklyn Bridge, but the project was taken over by his son, Washington Roebling, who became an invalid soon after. His wife, Emily Warren Roebling, saw the bridge through to its completion, in 1883. Technically, the bridge overcame many obstacles through the use of huge pneumatic caissons, into which compressed air was pumped so that men could work in the dry; but, more important, it was the first suspension bridge on which steel wire was used for the cables.

Question: What X-ray technique produces images of internal body structures as visual “slices” of the body?

Answer: Computerized axial tomography (CAT) was developed during the early 1970s. In this procedure a narrow beam of X-rays sweeps across an area of the body and is recorded not on film but by a radiation detector as a pattern of electrical impulses. Data from many such sweeps are integrated by a computer, which uses the radiation-absorption figures to assess the density of tissues at thousands of points. The density values appear on a television-like screen as points of varying brightness to produce a detailed cross-sectional image, like a slice, of the internal structure under scrutiny.

Question: Which pioneer of modern rocketry was inspired to his life’s work by a science fiction novel?

Answer: In 1898 a young Robert Goddard’s imagination was fired by the H.G. Wells science fiction novel War of the Worlds. Shortly thereafter, as he recounted, he dreamed of constructing a workable spaceflight machine.

Question: Because polyacrylonitrile fibres accept a dye and can be spun into light, lofty yarns, they are often used as a substitute for what natural fibre?

Answer: Most polyacrylonitrile (PAN) produced is employed in acrylic fibres, which are defined as fibres that contain 85 percent or more PAN. A copolymer containing PAN and 2 to 7 percent of a vinyl comonomer such as vinyl acetate can be readily spun to fibres that are soft enough to allow penetration by dyestuffs. Acrylic fibres are soft and flexible, producing lightweight, lofty yarns. Such properties closely resemble those of wool, and hence the most common use of acrylics in apparel and carpets is as a wool replacement.

Question: What did William Symington invent in 1802 when he put a steam engine, a connecting rod and crank, and a wheel on the Charlotte Dundas?

Answer: William Symington was the British engineer who in 1801 patented a new engine utilizing a connecting rod and crank, a system that proved superior for paddle-wheel operation. This engine was used in 1802 to propel the Charlotte Dundas on the Forth and Clyde Canal, thus launching the first steamboat fitted for practical operations.

Question: Which European-born inventor secured a fortune by bringing his concept of the rotating magnetic field, the basis of most alternating-current machinery, to the United States?

Answer: At Budapest Nikola Tesla visualized the principle of the rotating magnetic field and developed plans for an induction motor that would become his first step toward the successful utilization of alternating current. In May 1885 the Westinghouse Electric Company in Pittsburgh bought the patent rights to Tesla’s polyphase system of alternating-current dynamos, transformers, and motors.

Question: Which metal is used to make the filament of an incandescent light bulb?

Answer: Tungsten was first commercially employed as an incandescent lamp filament material and thereafter used in many electrical and electronic applications.

Question: What device converts sunlight to electricity?

Answer: Sunlight may be converted directly into electricity by photovoltaic cells, also called solar cells. In such cells, a small electrical voltage is generated when light strikes the junction between a metal and a semiconductor (such as silicon) or a junction between two different semiconductors.

Question: In the 1970s, which pair of American inventors on the West Coast produced the first personal computer to appeal to a broad market?

Answer: In the 1970s Steve Jobs and Stephen Wozniak produced the first personal computer to appeal to a broad market: the Apple II.

Question: What machine patented by Barthélemy Thimonnier in 1830 was destroyed by rioting tailors?

Answer: After several attempts, a practical sewing machine was patented in 1830 by Barthélemy Thimonnier, of Paris, who produced 80 machines to manufacture army uniforms. Thimonnier’s machines, however, were destroyed by a mob of tailors who feared unemployment.

Question: After gaining fame between 1800 and 1815 for his laboratory work in gases and electrochemical reactions, Humphry Davy went on to produce what practical, everyday invention?

Answer: About 1815 Humphry Davy began to study, for the Society for Preventing Accidents in Coal Mines, the conditions under which mixtures of firedamp and air explode. This led to his invention of the miner’s safety lamp and to subsequent researches on flame, for which he received the Rumford Medal from the Royal Society and, from the northern mine owners, a service of plate (eventually sold to found the Davy Medal).

Question: What important new technology was introduced by Vladimir Zworykin’s iconoscope of 1923 and kinescope of 1924?

Answer: In 1923 Vladimir Zworykin filed a patent application for the iconoscope, or television transmission tube, and in 1924 an application for the kinescope, or television receiver. These two inventions formed the first all-electronic television system.

Question: Which strong yet workable form of iron was the dominant engineering metal until it was replaced by steel?

Answer: The manufacture of iron artifacts then involved heating blooms in a fire and hammering the red-hot metal to produce the desired objects. Iron made in this way is known as wrought iron. The eventual decline in the use of wrought iron was brought about by a series of inventions in the 19th century that allowed furnaces to operate at temperatures high enough to melt iron. It was then possible to produce steel, which is a superior material.

Question: The 18th-century scientist who first measured both blood pressure in humans and transpiration in plants was also an inventor. He developed technology that could convey fresh air into prisons, ships’ holds, and granaries. Who was he?

Answer: One of Stephen Hales’s best-known techniques concerned the measurement of water vapour emitted by plants (transpiration). Hales was the first to quantitatively measure blood pressure, and he measured the capacity of the left ventricle of the heart, the output of the heart per minute, and the speed and resistance to flow of blood in the vessels. As an inventor, he developed an artificial ventilator (a modified organ bellows) that could convey fresh air into prisons, ships’ holds, and granaries.

Question: Binoculars are commonly designated as 6 x 30, 7 x 50, or 8 x 30. What do these numbers indicate?

Answer: The binoculars designation 6 x 30 can be interpreted in this manner: the first number, 6, indicates the magnification and the second, 30, the diameter of the objective lens in millimetres. This latter figure is a measure of the light-gathering power of the instrument.

Question: What American invention, patented in 1794, changed the economy of an entire region, yet it was “so valuable as to be worthless to the inventor”?

Answer: After perfecting his cotton gin, Eli Whitney secured a patent (1794), and he and his friend Phineas Miller went into business manufacturing and servicing the new gins. However, the unwillingness of planters to pay the service costs and the ease with which the gins could be pirated put the partners out of business by 1797. When Congress refused to renew the patent, which expired in 1807, Whitney concluded that “an invention can be so valuable as to be worthless to the inventor.”

Question: What was Hugo Junkers’s J-1 Blechesel (“Sheet Metal Donkey”) of 1915?

Answer: Hugo Junkers patented a flying-wing design in 1910, the same year in which he established an aircraft factory at Dessau. His J-1 Blechesel (“Sheet Metal Donkey”) monoplane was the first successful all-metal airplane (1915), and his F-13 was the first all-metal transport (1919). .

Question: While working on models for various wing surfaces, Lawrence Hargrave invented what device?

Answer: In Australia in 1893, British-born aviation pioneer and inventor Lawrence Hargrave contrived the box kite, or cellular kite, as a by-product of his research to develop a stable three-dimensional lifting surface for powered manned flight. Exceptionally steady in high winds, Hargrave box kites flown in train, using flying line of piano wire, were used for meteorologic work well into the 1920s.

Question: Which dye and flavouring agent, obtained from Crocus sativus, has been used for the colouring the robes of Buddhist priests and as perfume by the ancient Greeks and Romans?

Answer: The purple-flowered saffron crocus, Crocus sativus, is a bulbous perennial of the iris family (Iridaceae) treasured for its golden-coloured, pungent stigmas, which are dried and used to flavour and colour foods and as a dye. A golden-coloured, water-soluble fabric dye was distilled from saffron stigmas in India in ancient times. Shortly after the Buddha died, his priests made saffron the official colour for their robes. The dye has been used for royal garments in several cultures. As a perfume, saffron was strewn in Greek and Roman halls, courts, theatres, and baths.

Question: The Sydney Harbour Bridge, completed in 1932, is an example of what type of bridge?

Answer: The Sydney Harbour Bridge, in New South Wales, Australia, is a steel arch bridge with a span of 495 metres (1,650 feet) that was begun in 1924 and completed in 1932. The Sydney Harbour Bridge is a two-hinged arch, with its deck 52 metres (172 feet) above the water.

Question: For his visual signal line, employing a series of towers rigged with two arms that adopted various positions, French engineer Claude Chappe coined which term?

Answer: Claude Chappe and his brother Ignace built a series of towers on heights between Paris and Lille. Each tower was equipped with a pair of telescopes, one pointing in either direction, and with a two-arm semaphore (a word derived by Claude Chappe from the Greek for “bearing a sign”). In August 1794 the Chappe semaphore brought to Paris in less than an hour the news of the capture of Conde-sur-l’Escaut from the Austrians. The system was soon widely copied elsewhere in Europe.

Question: Of what practical use in the 19th century was a Helmholtz resonator (which is, essentially, a hollow sphere communicating with the outside through a short neck and small opening)?

Answer: An important type of resonator with acoustic characteristics is the Helmholtz resonator, named for the German physicist Hermann von Helmholtz. Essentially a hollow sphere with a short, small-diameter neck, a Helmholtz resonator has a single isolated resonant frequency that is determined by its volume and by the length and area of its neck. The isolated resonance of a Helmholtz resonator made it useful for the study of musical tones in the mid-19th century.