Creating the Twentieth Century

by Vaclav Smil

  The first portable electric vacuum cleaner, brought out in 1905 by Chapman & Skinner Co. in San Francisco, was an unwieldy machine weighing a little more than 40 kg with a fan nearly half a meter across to produce suction. The familiar upright machine (patented in 1908) was the invention of James W. Spangler. William Hoover’s Suction Sweeper Co. began its production in 1907 and introduced its 0 model, weighing about 18 kg, a year later, and a high-speed universal motor for vacuum cleaners became available in 1909. The key features of the early Hoover arrangement are still with us: long handle, disposable cloth filter bag, and cleaning attachments. Electrolux introduced its first canister model in 1921. The first radical departure from the basic pre-1910 design came only with James Dyson’s invention of nonclogging Dual Cyclone vacuum during the 1980s (Dyson 1998).

  The age of electricity also brought new diagnostic devices and medical equipment whose basic modes of operation remain unchanged but whose later versions became more practical, or more reliable, to use (Davis 1981). The first dental drill powered by a bulky and expensive DC motor (replacing previous hand cranks, springs, and foot treadles) was introduced in 1874, and plug-in drills became available by 1908. A small battery was all that was needed to power the first endoscope, a well-lit tube with a lens for viewing the esophagus, designed in 1881 by a Polish surgeon Johann Mickulicz (1850–1905). At Buffalo exhibition in 1901, visitors could see for the first time an incubator for premature babies, and two years later Willem Einthoven (1860–1927) designed the first electrocardiograph (he was awarded the Nobel Prize for Physiology or Medicine in 1925), and the device has been manufactured for diagnostic use since 1909 (Davis 1981).

  By far the most important diagnostic contribution that would have been impossible without electricity began with Wilhelm Conrad Rontgen’s (1845–1923) experiments with electric discharges in highly evacuated glass tubes. That led, on November 8, 1895, to the discovery of x-rays (Brachner 1995). Their value as a diagnostic tool was appreciated immediately, and consequently, in 1901 when the President of the Royal Swedish Academy of Sciences was presenting Röntgen with the first Nobel Prize in Physics, he noted that they were already in extensive use in medical practice (Odhner 1901). By 1910 their use was standard in medical diagnostics in large cities of Western countries, and they also found many applications in science and industry.

  Pre-WWI decades also set a number of basic management practices in the electric industry. Already in 1883 John Hopkinson (1849–1898) had introduced the principle of the two-part tariff method of charging for the consumed electricity, and the combination of a fixed (basic service) charge and a payment for the used quantity have been standard for more than a century. And almost immediately, the industry had to deal with the challenge of variable demand. As long as the electricity demand was dominated by lighting, the daily load factors of generating stations were very low, often no more than 8–10%, and in 1907 the average nationwide load for the United Kingdom was just 14.5%. That is why utilities were eager to see the installation of more electric motors, be they for lifting, in manufacturing, or for electric traction, and also looked for opportunities to reduce the large disparities between peak and average loads.

  Electricity use for traction had begun on a small scale already in the early 1880s with the first electric tramway built by Werner Siemens in Berlin’s Lichterfelde in 1881, and all major modes of electrically driven urban and intercity transport were introduced before 1913 (figure 2.25). The relevant first British dates were as follows (Electricity Council 1973): a short DC railway line in 1883 (on the beach at Brighton), tramway in 1885, underground railway 1890 (in London), main-line railway electrification 1895, AC railway line in 1908, and trolley buses in 1911 (but Werner Siemens had built the first trolley bus in Berlin already in 1882).

  In the United States, the first electric streetcars were introduced by Frank J. Sprague (1857–1934) in Richmond, Virginia, in 1888 (cars lit with electric lights traveled at 24 km/h), and soon afterward in Boston (Cambridge). The subsequent diffusion of this innovation was very rapid: within five years 14 of the 16 U.S. cities with more than 200,000 people and 41 of 42 cities with populations between 50,000 and 200,000 had electric streetcars. By 1900, there were 1,200 such systems in operation or under construction; by 1902, 99% of the old horse-drawn systems were converted, and by 1908, more than 1,200 companies owned about 62,000 km of electrified track and elevated railways (Dyer and Martin 1929; Sharlin 1967).

  As Hunter and Bryant (1991:206) put it, “it was a quick and complete revolution in urban transportation that touched lives of nearly all Americans living in cities,” and, lighting excepted, it brought electricity’s benefits to more people than any other application at that time. In 1892 Sprague introduced a multiple controller for operating several motors from the lead car at one time, opening up the applications for multicar trains and subways. Electric traction eventually spread from subways and commuter trains to high-speed rail links. Advances were rapid: already by 1902 Siemens & Halske was running an experimental four-motor polyphase car of 2.2 MW at speeds exceeding 160 km/h (Perkins 1902). All of today’s fastest trains are electric. The French TGV, current speed record holder, draws 25 kV at 50 Hz from a fixed overhead wire; the current is then stepped down by massive transformers to 1,500 V, and it is supplied to synchronous 1.1 MW AC traction motors (TGVweb 2000).

  FIGURE 2.25. Electric streetcar between Frankfurt-am-Main and Offenbach had conductors of wrought iron (diameter of 3 cm) suspended by iron wires that were attached to telegraph poles. Identical arrangement was used in many other European cities. Reproduced from Scientific American, August 26, 1882.

  In addition to transportation and industrial motors, electric welding, electrometallurgy, and electrochemical industries (particularly after Hall-Héroult process for producing aluminum was introduced in 1886) emerged as major industrial users of electricity. Electric arc welding with a carbon electrode was patented in the United Kingdom in 1885 by Nikolai Benardos and Stanislaw Olszewski, and seven years later Charles L. Coffin (1844–1926) got the U.S. patent for a metal electrode (Lebrun 1961). Advances in electrometallurgy were made possible by William Siemens’s invention of electric furnace in 1878. A quantitatively small but qualitatively immensely important use of electricity is in the enormous variety of monitoring, and analytical devices in industry, science, health care, and, of course, millions of personal and mainframe computers.

  As is always the case with technical innovations, diffusion of electricity was affected by national idiosyncrasies. Inertial reliance on the long-established steam power using cheap coal slowed down the British embrace of electricity, and the unfortunate Electric Lighting Act of 1882, which limited the operating licenses to seven years and gave the local authorities the right to take over the company assets after 21 years, created another disincentive that was remedied only by a new legislation in 1888. These two factors explain why the United States and Germany, rather than the United Kingdom, pioneered widespread applications of electricity. Statistics of electricity generation tell the story: by 1900, the national totals were (in GWh) 0.2 in the United Kingdom, 1.0 in Germany, and nearly 5 in the United States, and by 1914 the respective figures rose to 3.0, 8.8, and 24.8, which means that the United States per capita generation reached 250 Wh/year, compared to about 135 Wh in Germany and to just 70 Wh in the United Kingdom (USBC 1975; Mitchell 1998).

  American and German cities were also far ahead of English urban areas in developing the symbiotic relationship between electricity and industrial production (Martin 1922; Hughes 1983; Platt 1991). By 1911 Chicago used more than 80% of its electricity for stationary and traction power; the analogical share was 66% in Berlin, but only 39% in London, where lighting still dominated the demand. And in both the United States and Germany, developments were disproportionately driven by just two companies: after the early 1890s it was General Electric and Westinghouse that introduced most of the technical advances in American electric industry, and AEG and Siemens had the sa
me role in Germany (Strunk 1999; Feldenkirchen 1994).

  American electrification efforts paid off rapidly in cities: by 1906 Boston’s average per capita output of electricity was nearly 350 Wh/year, New York’s almost 300 Wh/year, and Chicago’s 200 Wh/year, compared to just over 40 Wh/year in London (Fleming 1911). But the country’s large size delayed the access to electricity in smaller towns and particularly in rural areas: financial returns were either very low, or nil, given the high cost of extending the transmission lines from central stations. Only about 5% of potential customers had electricity in 1900; 10 years later still only 1 in 10 American homes was wired. The share surpassed 25% by 1918, and most of the urban households became connected only by the late 1920s (Nye 1990).

  In technical terms, European and North American developments proceeded along very similar lines, as generating machinery was designed for more efficient performance with higher pressures and greater steam superheat, as established central stations grew by adding larger turbogenerators (often produced in large series of standard sizes), and as long-distance transmission steadily progressed toward higher AC voltages. Electric motors surpassed lights as the principal users of electricity in all industrializing countries (e.g., in the United Kingdom the crossover had taken place already before 1910), but Europe and North America retained distinct operating parameters for electricity distribution and its final use in households.

  FIGURE 2.26. Major types of electric plugs used around the world. Simplified from a more detailed illustration in USDC (2002).

  Early polyphase systems operated with frequencies ranging from 25 to 133.33 Hz, but already by 1892 Westinghouse Co. had adopted just two rates, 25 Hz for large-load supply and 60 Hz for general distribution. Accordingly, household and office supply in North America is now single-phase AC of 120 V (maximum of 125 V) at 15 A and 60 Hz; the current oscillates 60 times every second between ± 170 V, averaging 120 V with the high voltage supplied to the smaller prong. In contrast, pre-WWI trend in the United Kingdom was toward an increasing variation rather than standardization, and in 1914 London had no less than 10 different frequencies and a multitude of voltages (Hughes 1983). The European standard eventually settled on single-phase AC of 220 V at 50 Hz, but amperage is not uniform; for example, Italy uses 10 A or 16 A (BIA 2001). Japanese ratings conform to the U.S. standard; Chinese, to the European one.

  But these disparities are nothing compared to the bewildering variety of sockets (shaped as circles, rectangles, or squares), plugs (with flat or rounded blades, and with or without grounding pins), and connectors used by households: worldwide there are 15 basic types of electric plugs and sockets with different arrangements of flat and round pins (ITA 2002; figure 2.26). Unfortunately, there is little hope that this unhelpful diversity will be eliminated any time soon; the only solution when using incompatible devices and plugs is to buy appropriate transformers and adapters.

  3

  Internal Combustion Engines

  After supper my wife said, “Let’s go over to the shop and try our luck once more…” My heart was pounding. I turned the crank. The engine started to go “put-put-put,” and the music of the future sounded with regular rhythm. We both listened to it run for a full hour, fascinated, never tiring of the single tone of its song. The longer it played its note, the more sorrow and anxiety it conjured away from the heart.

  Karl Benz recalling the first successful run of his

  two-stroke engine on the New Year’s Eve of 1879

  Karl Benz (1844–1929) had a very good reason to be pleased as he listened to his two-stroke engine: his contract machine-building business was failing and a new gasoline-fueled engine, one that he designed and built in his free time, was to solve his difficulties. But neither he nor his wife Bertha (1849–1944)—who had more faith in his inventions that he did himself—could have foreseen the consequences of this experiment. By July 1886, Benz mounted a successor of that engine, still a low-powered but now a four-stroke machine, on a three-wheel chassis that was surmounted by two rather high-perched seats, an innovation that made him eventually famous as the “inventor” of automobile (figure 3.1). Quotation marks are imperative because the motor car is one of the least appropriate artifacts to have its commercial introduction ascribed to a single inventor (Beaumont 1902; Walz and Niemann 1997).

  FRONTISPIECE 3. Cover of the first catalog published by Benz & Cie. in 1888 shows a slightly modified version of the three-wheel vehicle patented and publicly driven for the first time in 1886. Courtesy of DaimlerChrysler Classic Konzernarchiv, Stuttgart.

  But Benz was surely right about the music of the future. In a few generations its rhythm became ubiquitous, and there are now few other human creations that have been so admired and cherished and yet so disparaged and reviled as internal combustion engines. In these ingenious devices, steel pistons are tightly confined in cylinders as they are rapidly driven by miniexplosions of compressed fuel, and their frenzied reciprocating motion is then converted into smooth rotation that is transmitted to wheels or propellers. But whatever are our attitudes to these machines, their regular rhythm has come to define the tempo of modern civilization. Installed in cars, they bring choices and opportunities of personal freedom and mobility as well as environmental degradation and traffic congestion. They also enlarge the world of commerce as they power trucks, ships, and planes and, less visibly, as they energize many kinds of off-road machines that are now indispensable in mining and construction.

  FIGURE 3.1. Karl Benz. Photograph courtesy of DaimlerChrysler Classic Konzernarchiv, Stuttgart.

  The process of introducing and diffusing internal combustion engines is an even better example of multifaceted, complex, synergistic origins of a major technical advance than is the formation of electric systems described in chapter 2. The new engines began their tentative careers as relatively inefficient coal-gas-fueled sources of stationary power, and as their performance improved they found many other useful applications besides eventually propelling machines of many kinds, the most demanding being civilian and military aircraft. Consequently, it is useful to separate the history of internal combustion engines into five stages, some being consecutive or partially overlapping, and others concurrent.

  The first period embraces failed intermittent efforts to build explosively powered machines, a quest that goes back to the 17th century and whose pace picked up during the first half of the 19th century. This stage culminated with the first serious attempts to build steam-powered powered vehicles whose tests kept the idea of a self-propelled road machine in public consciousness: Walter Hancock’s (1799–1852) series of quaintly named machines—Infant, Enterprise, Autopsy, Era, and Automaton—built during the early 1830s was particularly notable (Beaumont 1902). The steam engine has obvious disadvantages in road transportation, but it was not eliminated as a serious contender for powering passenger vehicles until the very end of the 19th century. Even some of the early proponents of powered flight tried to use it, an extraordinarily challenging task given its inherently high mass/power ratio.

  The second stage in the development of internal combustion engines saw the construction of first commercially promising stationary machines powered by coal gas during the 1850s and their subsequent improvement, particularly thanks to the efforts of Nicolaus Otto and Eugen Langen. Their company, and its licensees, eventually produced thousands of relatively small horizontal engines for a variety of workshop and industrial uses. Initially, these were all noncompression and mostly double-acting machines, but Otto’s pioneering 1876 design of a compression four-stroke engine proved immediately popular. This machine embodied key operating features of all modern engines, but it was not suitable for transportation. Although the design of Otto’s engine was promptly patented, its priority, as I explain below, was later disputed.

  Practical automotive designs emerged during the third stage with the development of gasoline-powered engine and with its use in the first carriagelike vehicles of the 1880s. This period is usually portrayed
as a largely German invention of the automobile beginning with gasoline engines and motorized carriages built by Gottlieb Daimler and Wilhelm Maybach and, independently, by Karl Benz. But better engines are not the only precondition of a practical and reliable machine that is convenient and reasonably comfortable to use: a lengthy list of other requirements ranges from the overall machine design and good transmission of the generated power to cushioned wheels. These improvements began during the early 1890s with a fundamental redesign of motorized four-wheeled vehicles by Emile Levassor and continued with other important contributions made in France, Germany, the United States, and the United Kingdom. Another notable event of that intensively innovative period was Rudolf Diesel’s (1858–1913) patenting of a new kind of engine, one that did not need either carburetor or a sparking device and that could use heavy oils rather than just the lightest liquid hydrocarbon fractions.

  The fourth stage includes the rapid maturation of high-performance four-stroke engines and gradual emergence of road vehicles whose engine design and entire mechanical arrangement set the trends of automotive design for much of the 20th century. This stage also included the pioneering reciprocating engines for the first airplanes, whose subsequent development greatly advanced the performance, efficiency, and reliability of the new prime mover.

  But if motorized vehicles were to claim a mass market, they could not be produced in the same way as they were during the first two decades of their existence, that is, in artisanal fashion either as unique items or in very small series by skilled (originally mostly bicycle) mechanics. Hence, the fifth key stage of the early development of internal combustion engines (and one that was largely concurrent with the fourth) was marked by the first steps toward highly efficient mass production of automotive engines and other car parts that eventually made the car industry the leading manufacturing activity of every large modern economy. Only a short lag separated these advances from a no less impressive large-scale production of aircraft.