Tesla: The Life and Times of an Electric Messiah (21 page)

Appendixes

Electrifying Science Facts

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Electrical Science in 1875

The ancient Greeks discovered that you could produce static electricity by rubbing amber with silk. In the 18th century, scientists such as the American Benjamin Franklin (1706 – 90) and the Briton Henry Cavendish (1731 – 1810) made a systematic study of the phenomenon.

In 1791, the Italian Luigi Galvani (1737 – 98) discovered electricity in animal tissue when he saw a frog’s leg twitch when touched by two different metals. This led his friend Alessandro Volta (1745 – 1827) to make the first electric battery in 1800.

Danish physicist Hans Christian Ørsted (1777 – 1851) discovered the relationship between electricity and magnetism in 1820 when he saw a compass needle being deflected when an electric current was turned on and off. French physicist André-Marie Ampère (1775 – 1836) developed this into the science of electrodynamics.

In 1831, British scientist Michael Faraday (1791 – 1867) demonstrated the laws of electromagnetic induction, producing a current in a coil by moving a magnet back and forth inside it. This led to the development of both the electric motor and the generator where coils of wire were mounted in a rotor, or armature, within a magnetic field.

As the magnetic effect is only apparent when the current is turned on and off, an electric motor has a commutator – that is, a split ring with electrical contact, or brushes, resting on either side. As the motor turns, contacts switch, reversing the current flow in the coil. Similarly, a generator needs a commutator to prevent the current reversing as the rotor turns.

 

The Gramme Dynamo

With the rapid development of the telegraph system in the 1840s and 1850s, what was needed was direct current (DC) that flowed in only one direction. This is the type normally produced by batteries.

Even with a commutator, introduced by Parisian instrument-maker Hippolyte Pixii (1808 – 35) in 1832, the current delivered by a generator, while not reversing, was not smooth and constant like that from a battery. It builds to a peak then drops back to zero again. However, Belgian electrical engineer Zénobe-Théophile Gramme (1826 – 1901) demonstrated his Gramme dynamo at the French Academy of Sciences in 1871. By increasing the number of coils on the rotor and the number of sections on the commutator, it could produce a near constant direct current.

Shown at the International Exhibition in Vienna, one Gramme dynamo was connected to another one which acted as a motor. Until then, motors had only been powered by expensive batteries. Gramme’s business partner, French engineer Hippolyte Fontaine (1833 – 1910) had demonstrated that power could be transmitted from one place to another without the inefficient shafts, belt, chains or ropes used to connect steam engines to machines – with obvious advantages for industry.

 

What is Alternating Current?

The electricity from a battery, lightning or a Van de Graaf generator that produces a static charge is direct current. It flows in only one direction. Alternating current flows in one direction, then the other. It cycles through peaks and troughs as it changes direction.

With a direct current, when a switch is thrown a magnetic field builds up around the wire, inducing a current in any conductor nearby. This only occurs when the field is building up or when the field collapses when the current is switched off. With an alternating current, the electric current is effectively being switched on and off all the time, inducing an alternating current in the secondary conductor. This property is utilized in an induction motor, where a current is induced in secondary coils on the rotor, and in a transformer, where the voltage is stepped up and down.

 

Pearl Street Power Station

The first electric lights were arc-lamps that gave off light from electric sparks. But in 1879, Edison came up with the improved incandescent lamp. Arc lamps had been connected in series – if one failed, all of them went out. Edison connected his lamps in parallel, so each faulty bulb could be replaced individually. This had created an astonishing demand for electric power. Edison built his first DC power station on Pearl Street in lower Manhattan in 1882, initially to power 400 lamps owned by 85 customers. It quickly became a monopoly and by 1884 it was serving 508 customers with 10,164 lamps. The electricity was carried above ground on poles with dozens of crooked crossbeams supporting sagging wires. The exposed electrical wiring was a constant danger and unsuspecting children climbing the poles would suffer lethal electric shocks. In spite of the perils, wealthy New Yorkers rushed to have their homes wired, the most important being the banker, J.P. Morgan, who had invested heavily in Edison.

 

The Transformer

The transformer uses the same principles of electromagnetic induction employed in electric motors and generators. Two coils of wire are wound around a single iron core. When an electrical current is passed through one of them, it magnetizes the iron core. This, in turn, induces an electric current in the other one. The voltage is stepped up or stepped down according to the ratio of the number of turns of wire in each coils. However, induction only works when the electrical current is being switched on and off again, so an alternating current rather than a direct current must be used.

The transformer is a vital component of any power distribution system as transmission losses are much smaller when the voltage is higher – as less current is needed to convey the same amount of energy. So electricity generated at a power station is stepped up in voltage using a transformer before it reaches the transmission lines. Then, at its destination, it is stepped down for use in the home or factory.

 

Harold Brown - Dying in the Name of Science

Under the headline: ‘Died for Science’s Sake – A Dog Killed With The Electric Current’,
The New York Times
of 31 July 1888 reported on one of Harold P. Brown’s demonstrations. In Professor Chandler’s lecture room at Columbia’s School of Mines, Brown told an invited audience that he represented no company and no financial or commercial interest. He also maintained that he had proved by repeated experiments that a living creature could stand shocks from a continuous current much better than from an alternating current. He had applied 1,410 volts of DC to a dog without fatal results, but had repeatedly killed dogs with 500 to 800 volts of alternating current.

Brown then brought out a Newfoundland mix weighing 76 pounds (34 kg). The dog was muzzled and tied down inside a wire cage. The newspaper reported:

Mr Brown announced that he would first try the continuous current at a force of 300 volts [DC]. When the shock came the dog yelped and then subsided. A relay has been attached to the apparatus, which shut off the current almost as soon as it was applied. When the dog got 400 volts he struggled considerably, still yelping. At 700 volts he broke his muzzle and nearly freed himself. He was tied again. At 1,100 volts his body contorted with the pain of the brutal experiment. His resistance to the current then dropped from 1,500 to about 2,500 volts.

‘He will be less trouble,’ said Mr Brown, ‘when we try the alternating current. As these gentlemen say, we shall make him feel better.’ It was proposed the dog be put out of his misery at once. This was done with an alternating current of 330 volts killing the beast.

When Brown brought out another dog, an agent from the American Society for the Prevention of Cruelty to Animals stepped in. Meanwhile, the assembled electricians said that the dog had been weakened by the DC current before the AC was applied. But Brown insisted that the only places AC should be used were ‘the dog pound, the slaughter house and the State prison’.

 

What is Viscosity?

All fluids have viscosity. Thick fluids such as molasses have a high viscosity; thin ones, such as air, a low viscosity. All fluids, to a greater or lesser extent, stick to solid surfaces. The molecules near to the surface adhere to it and travel at the same velocity. Molecules a little further away are slowed by a viscous interaction with those stuck on the surface. Further away still, the fluid flows freely. The transition between the layer stuck to the surface and the free-flowing stream is called the boundary layer. Tesla found that he could use ‘viscous shear’ in the boundary layer to transfer energy from the fluid to the turbine.

 

Explaining Standing Waves

A standing wave is caused by the combination of two waves moving in opposite directions and is usually found where a wave is reflected from a surface or the end of a wire. The two waves are superimposed and either add together or cancel each other out. A vibrating rope tied at one end will produce a standing wave. At some positions along the rope there is no movement. These points are called nodes. Either side, where the movement is the greatest, are antinodes.

 

The Edison Medal

The Edison Medal was created in 1904 by a group of Edison’s friends and associates as an annual award to be given to a living electrician for ‘meritorious achievement in electrical science and art’. In 1909, the American Institute of Electrical Engineers agreed to present it as their highest award. The first recipient was Tesla’s rival Elihu Thomson. George Westinghouse and Alexander Graham Bell also received the award. The medal is now presented by the Institute of Electrical and Electronics Engineers, formed when the AIEE merged with the Institute of Radio Engineers.

Tesla's Friends and Contemporaries

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Thomas Alva Edison (1847 – 1931)

Born in Ohio, Edison had little schooling. At the age of 12 he got a job on the railroad where he learned telegraphy. He went on to develop the duplex system that sent two messages at once and a printer that converted electrical signals into letters.

He quit and went into business for himself, developing the quadruplex system, which sent four messages at once for Western Union and their rivals. With the help of his father, he established a laboratory and machine shop at Menlo Park, New Jersey, which became the world's first industrial research facility. There he developed underwater cable for the telegraph, set about improving the primitive telephone developed by Alexander Graham Bell, and inventing the phonograph. This brought him worldwide fame as the
Wizard of Menlo Park
.

He worked on the incandescent light bulb, though battles over patents ensued. He also developed electric motors and generators to power his lighting systems, first on the steamship
Columbia
, then on buildings in New York and London.

A pioneer in motion pictures, he also developed batteries for submarines and the Model T Ford. In all, he took out a world record 1,093 patents and remains the most famous inventor in American history.

 

Alexander Graham Bell (1847 – 1922)

Edinburgh-born Bell first visited the USA in 1871 where he demonstrated his father's method of teaching speech to the deaf. The following year he opened a school for teachers of the method in Boston.

With young technician Thomas Watson, he set to work on developing ways of using electricity to transmit sound, getting his patent for the telephone in 1876. Hundreds of patent suits followed. Nevertheless, the Bell Telephone Company was established the following year, successfully fighting off suits by two subsidiaries of the Western Union Telegraph Company.

Bell also invented the photophone, which transmitted sound on a beam of light, and the Graphophone, that recorded sound on wax cylinders. He experimented with sonar detection, huge flying kites and hydrofoils, while continuing to find ways to aid the deaf.

 

George Westinghouse (1846 – 1914)

George Westinghouse was a descendent of the aristocratic Russian von Wistinghousen family. His father was also an inventor with six patents for farming machinery to his name. In his father's machine shop in Schenectady, New York, the young Westinghouse experimented with batteries and Leyden jars – glass jars coated with metal foil, used for storing electrical charge. At 15, he made his first invention, a rotary steam engine. After serving in both the US Army and Navy during the American Civil War, he attended the nearby Union College, but soon dropped out. In 1865, he patented his rotary engine, and a device for putting derailed freight cars back on the tracks. Soon after, he designed a reversible cast-steel frog which prolonged the life of railroad track switches.

Having been involved in a near collision on the railway, he put his mind to improving the braking system which, until then, had depended on a brakeman on every carriage. His first system, using steam, proved impractical. But then in 1869 he came up with air-brakes that soon became standard in the US and Europe.

He then worked on signalling, devising an electrical system. With the aid of Tesla, Westinghouse entered the ‘War of the Currents', championing AC against Edison's DC system. By 1889, the Westinghouse Electric Corporation was a global company, employing over 500,000 people. However, in the financial panic of 1907, he lost control of the companies and retired altogether in 1911.

 

Lord Kelvin (1824 – 1907)

Scottish engineer, mathematician and physicist, William Thomson was knighted in 1866 and made a peer in 1892 for his services to science and engineering. He helped develop the Second Law of Thermodynamics, the mathematical analysis of electricity and magnetism, the electromagnetic theory of light, the geophysical determination of the age of the Earth and the basics of hydrodynamics. His work on submarine telegraph cables helped make Britain the hub of global communications. He perfected the mariner's compass and worked out the correct value of absolute zero. The units of the absolute temperature scale are named Kelvins in tribute to him.

 

James Clerk Maxwell (1831–79)

Born in Scotland, James Clerk Maxwell had already demonstrated colour photography and worked on the standardization of electrical units when, in 1865, he published
A Dynamical Theory of Electrical Field
. In it, he sought to convert the physical laws of electromagnetic induction discovered by Faraday into mathematics. His famous equations showed that electric and magnetic fields travel through space as waves moving at the speed of light. This led him to propose that light was electromagnetic radiation and predicted the existence of radio waves.

 

Hermann von Helmholtz (1821 – 94)

Like many scientists of the day, Helmholtz worked in multiple fields, including physiology, optics, meteorology, hydrodynamics and the philosophy of science. He is best known for the Law of Conservation of Energy. Between 1869 and 1871, he studied electrical oscillation, and he noted the oscillations of electricity in a coil when it was connected to a Leyden jar. He sought to measure the speed of electromagnetic induction, but left the determination of the length of electric waves to his star pupil, Heinrich Hertz.

 

Heinrich Hertz (1857 – 94)

After studying under Helmholtz, Hertz began his investigation of the theories of James Clerk Maxwell. He developed primitive equipment to generate electromagnetic waves and measured their wavelengths and velocity. Demonstrating that they could be reflected and refracted like light and radiant heat, he showed that light and heat were also electromagnetic waves. He was just 36 when he died.

 

Michelson-Morley Experiment

Devised by A.A. Michelson and later refined with Edward Morley, the Michelson-Morley experiment sought to detect the velocity of the Earth through the all-pervading ether which Helmholtz and Hertz maintained electromagnetic waves were propagated through. A sensitive interferometer was used to compare the speed of light in two directions at right angles to each other. If the universe is filled with ether, the speed of light along the Earth's direction of travel should be less than its velocity at right angles to it. No difference was detected. Ergo the ether did not exist.

 

Guglielmo Marconi (1874 – 1937)

In 1894, Marconi began experimenting with an induction coil, a Morse key and a sparking gap, along with a simple detector, at his father's estate near Bologna. Devising a simple aerial, he increased the range to 1.5 miles (2.4 km). He moved to London where he filed his first patent in June 1896. Using balloons and kites, he increased the range still further. In 1899, signals were sent across the English Channel and the America's Cup used Marconi's equipment for ship-to-shore communication. The following year Marconi took out patent No. 7777, which enabled several stations to operate on different frequencies. This was overturned by the US Supreme Court in 1943 when it was shown that Tesla and others had already developed radio-tuning circuits.

In December 1901, Marconi transmitted a signal across the Atlantic from Cornwall in England to Newfoundland in Canada. This led to the discovery that the curvature of the Earth had proved no obstacle because radio waves reflected off ionized layers in the upper reaches of the atmosphere. Marconi continued to improve the range and efficiency of wireless devices and set up companies to exploit his discoveries. In 1909 he was awarded the Nobel Prize for physics and in 1932 the Marconi company won the contract to establish short-wave communication between England and the countries of the British Empire.

 

Mark Twain (1835 – 1910)

Born Samuel Langhorne Clemens, Twain was an American humorist and writer who found worldwide fame with
The Adventures of Tom Sawyer
(1876) and
The Adventures of Huckleberry Finn
(1885). He was also known for his travel writing –
The Innocents Abroad
(1869),
Roughing It
(1872) and
Life on the Mississippi
(1883).

 

Joseph Rudyard Kipling (1865 – 1936)

Born in Bombay (Mumbai), India, Kipling was a short-story writer, poet and novelist who chronicled the British Empire at the height of its power. He also wrote for children. Principally remembered for the adventure novel
Kim
,
The Jungle Book
,
Just So Stories
, the short-story
The Man Who Would be King
and the poems
Mandalay
,
Gunga Din
,
The White Man's Burden
and
If–
, he won the Nobel Prize for Literature in 1907.

 

John Muir (1838 – 1914)

Born in Scotland, Muir emigrated to the US with his family in 1849. After studying science at the University of Wisconsin, he found work in a factory where he adapted and improved machinery. An accident nearly cost him his sight. In its aftermath he undertook a walk of nearly 1,000 miles (1,600 km) from Indiana to Florida. In 1868, he arrived in the Yosemite Valley in California and became an advocate for the preservation of the wilderness there. Due to his lobbying, National Parks were set up at Yosemite, Sequoia and elsewhere. In 1903, he accompanied President Theodore Roosevelt on a camping trip in the Yosemite region.

 

Richmond Pearson Hobson (1870 – 1937)

Graduating from the US Naval Academy in 1889, Hobson was given temporary command of the collier
Merrimac
during the Spanish-American War. Off Cuba, his ship was disabled by enemy fire and he scuttled her in the entrance to Santiago Harbour, blockading the Spanish Fleet. He and his crew of six were imprisoned in Morro Castle. When he was released in a prisoner exchange in 1898, he returned to the US to a hero's welcome. Women admirers flocked to him and he became ‘the most kissed man in America'. Awarded the Medal of Honor, he became a congressman. One of Tesla's closest friends, he said the inventor once told him that he had ‘never touched a woman'.

 

The X-Ray Man – Wilhelm Röntgen (1845 – 1923)

In 1895, while he was professor of physics at Würzburg, Germany, Röntgen noticed that when he ran an electric current through a partially evacuated glass tube it gave off a mysterious radiation that affected photographic plates. Unlike light this passed through paper, wood and aluminium, so he called them X-rays. Soon after, he took a picture of the bones in his wife's hand. News of his discovery spread quickly round the world and he was awarded the first Nobel Prize in physics in 1901.

 

Hammond and Son

Mining engineer and philanthropist John Hays Hammond (1855 – 1936) gave Tesla $10,000 to develop his Telautomaton. Later his son, John (Jack) Hays Hammond Jr (1888 – 1965), developed Tesla's ideas and became known as ‘The Father of Remote Control'. At Yale, Jack developed electrically controlled steering and engine control for a boat, controlling the mechanisms at a distance using a wireless device. In 1909, he got his father to arrange a meeting for him with Tesla because there was some ‘important information' he needed from him. With Marconi wireless, which itself used Tesla Coils, attached to two 360-ft (110 m) towers, Jack could control a crew-less boat from a lookout station near his laboratory at Freshwater Cove. Later, Jack invited Tesla to speak at his graduation from Yale.

 

Tesla, a boxing fan

Tesla claimed to have made a study of heavyweight title fights after the 1892 match where street-fighter John L. Sullivan (1858 – 1918), who had held the world title for 10 years, was knocked out by college-educated ‘Gentleman Jim' Corbett (1866 – 1933). In 1927, he made headlines predicting the outcome of the rematch between Gene Tunney (1897 – 1978) and the ‘Manassa Mauler' Jack Dempsey (1895 – 1983) who, though he had lost the title a year earlier, was ahead in the betting.

The
New York Herald Tribune
said: ‘Sitting in this suite at the Hotel Pennsylvania, the 71-year-old inventor did not hedge or pussyfoot, but declared that Tunney was ‘at least 10 to 1 favourite'. On the basis of mechanics, Tesla said, ‘Tunney will hit Dempsey continuously and at will'. He added that Tunney also had the advantage because he was single. ‘Other things being equal,' Tesla said, ‘the single man can always excel the married man.' In his later years, Tesla would be seen dining with other boxers, including the ‘Midland Mauler' Jimmy Adamick and Yugoslav welterweight Fritzie Zivic.

 

J.P. Morgan (1837 – 1913)

The son of a successful financier, Junius Spencer Morgan (1813-90), John Pierpont Morgan began his career in 1857 with the New York banking firm of Duncan, Sherman and Company, which was the US representative of the London firm George Peabody and Company. By 1871 he was a partner at Drexel, Morgan and Company, soon the predominant source of government financing. In 1895, it became J.P. Morgan and Company, and one of the most powerful banking houses in the world. Because of his links with Peabody, Morgan was able to provide the rapidly growing US industrial corporations with capital from British banks.