Fig. 4.  Ricardo’s patented alcohol racing fuel is advertised in the London Times, 29 November, 1935, 13. 

SPECIAL MOTIVES:
Automotive Inventors and Alternative Fuels in the 1920s

Paper to the Society for the History of Technology, Oct. 19, 2007

By William Kovarik, Ph.D. 

wkovarik@radford.edu

Abstract

The history of alternative fuels, especially ethanol (ethyl alcohol), is not well understood. Although a successful alternative fuels industry has emerged in recent years, it remains an area in need of historical research. This paper explores alternative fuels as they were seen by three key automotive inventors-- Henry Ford, Charles Kettering (research head of General Motors) and Harry Ricardo (a British engineer). These three inventors anticipated the depletion of petroleum reserves within their lifetimes and considered ethanol as the best response in the context of their own motivations and world views.

Henry Ford hoped that widespread use of ethanol from farm products would strengthen rural economies. He backed a populist farming movement that continued through the 1960s. Charles Kettering and his staff at General Motors hoped to save the auto industry from an anticipated oil shortage. Kettering’s original special motive for developing tetraethyl lead was to allow higher compression engines that would be more efficient and more easily adapted to ethanol when oil ran out. British engineer Henry Ricardo, a leading engine designer, was concerned about Britain’s research efforts before and after World War I. Ricardo’s patented ‘Discol’ alcohol fuel formula was widely used for racing and became a popular consumer fuel in Britain from the 1930s through the 1960s.

All three automotive engineers were looking for a fuel that was not derived from coal or oil. They thought, along with most of their contemporaries, that ethanol would be the fuel of the future. In the first edition of his classic 1921 book on the internal combustion engine, Ricardo said it was an “absolute necessity to find an alternative fuel” and that alcohol was the most likely candidate.

But as the 1920s came to an end, and fears of an immediate oil crisis proved unwarranted, the original special motives for the development of alternative fuels systems became economically and politically problematic. Subsequent editions of Ricardo’s book contained no optimistic note about alternative fuels; the idea of moving from leaded gasoline to alcohol was abandoned at GM; and Henry Ford found a broader context for his agrarianism in soybean-based plastics and other industrial uses of farm products.

Keywords: ethanol, ethyl alcohol, biofuels, alcohol fuel, alternative fuel, anti-knock fuels, leaded gasoline, tetraethyl lead, oil shortage, petroleum shortage, Charles Kettering, Henry Ford, Harry R. Ricardo.

Introduction

This paper examines the attitudes of three historically important engineers regarding the use of ethanol as an alternative fuel. Henry Ford and Charles Kettering are among the most significant American mechanical engineers, while Harry R. Ricardo of England was the most significant figure in early 20^th century mechanical engineering there. All three had definite opinions concerning ethanol as both a direct substitute for petroleum and as an anti-knock additive when blended at 10 to 20 percent volume with gasoline. Their opinions are significant today with the resurgence of ethanol and other alternative fuels.

Ethanol was a well known fuel at the dawn of the automotive age and was in competition with petroleum on two levels – direct substitution for gasoline and octane boosting in blends with gasoline. The two levels of competition are not always easy to separate, especially since the main competitor on the additive level was “leaded” gasoline produced by a company called “Ethyl.” (Technically, the additive is tetraethyl lead).

Leaded gasoline was an economic success from 1926 until 1976, and in fact, its discovery at Charles Kettering’s General Motors laboratory was among the most celebrated achievements of automotive engineering. It was often portrayed as the result of genius, luck and a great deal of hard work. It is now considered to be a catastrophic failure and is banned for environmental and public health reasons.*

Ethanol, on the other hand, always seemed doomed to failure. Engineers often quipped that ethanol was “the fuel of the future—and it always will be,” since it was more expensive than leaded gasoline from the 1920s through the 1980s. It was, in a way, the red-headed step child of the energy industry. It was usually omitted from industry histories and discussions about fuel choices. Today ethanol can only be considered a success, although controversy about various efficiency, biodiversity and carbon footprint issues still attends its use. And in fact, it is for that very reason that the lack of historical perspective seems like such a glaring lacuna in the record and a reminder that technological roads not taken may still need to be remembered someday. (Note: A discussant on the panel where this paper was presented objected to considering ethanol a success in the modern context because, he argued, the technology was subsidized and environmentally problematic. In the author's opinion, this is historically inappropriate and impossibly restrictive).

Literature review

One of the great success stories exemplifying the power of science and invention in the 1920s and 30s was the General Motors development of leaded gasoline. The history of leaded gasoline was told in Thomas A. Boyd's 1957 memoir and biography of Charles Kettering, Professional Amateur and Rosamond Young's 1961 biography, Boss Ket.[1] Also, public relations articles and a few references in scientific papers may be found about the Ethyl controversy.[2] In 1978 Thomas Hughes discussed inventive styles using the example of the discovery of tetraethyl lead, which he said occurred in the style of an heroic or Edison-like individual effort in that it involved testing of all possible combinations.[3] In addition, the 1983 book Ethyl, historian Joseph C. Robert describes the General Motors development of leaded gasoline in a heroic style without noting that alternatives were seriously considered.[4] Even as late as 1996, an article about Kettering saw the development of leaded gasoline in the context of a successful and inventive solution to the knock problem.[5] The issue of lead poisoning – well appreciated in the 1920s and by the 1980s the basis of an international ban on leaded gasoline – was treated dismissively. “An outcry arose over the possibility” of a public health problem, the article said, even though it was far more than a simply outcry over a mere possibility. Kettering’s views on alternative fuels, as described below, were not considered. Another book, Dying for Work, also explored leaded gasoline from the public health side of the issue but not from the variety of technological alternatives.[6]

One book that dealt with both sides of the technological issue and described alternative fuels within the anti-knock context was the 1983 book, Boss Kettering. Historian Stuart Leslie noted the lack of success for ethanol and attributed it to economic and energy efficiency problems.[7] Only a few other authors put the issues into the context of the variety of fuel types. For instance, the difficulty facing alternative fuels technologies in the competition with petroleum and leaded gasoline additives was explained in 1949 as basically a problem of scientific prejudice by S.J.W. Pleeth[8] and as an instance of industry dominance by Forbidden Fuel by Bernton, Kovarik and Sklar in 1982.[9] The controversy over leaded gasoline and its alternatives was also described in a March, 2000 article in The Nation magazine.[10]

One reason that this literature may now seem dated is that new documentation has emerged concerning the General Motors research efforts led by Charles Kettering and the origins of the alternative fuels industry.[11] Some of this paper is based on the new documentation.

Fig. 1 -- Cover illustration from the Congress des Applications de L'Alcool Denature, 23 Dec., 1902, Automobile-Club de France.  The illustration aptly shows the hope for rural – urban balance, or the machine appropriately placed in the garden, as part of the early rhetoric surrounding the development of alcohol fuel.  The exhibit of alcohol fueled appliances at this Congress featured stoves, water heaters, coffee roasters, lamps and motors manufactured primarily in Germany. The exhibit toured Europe and the US for a decade and stops included the Jamestown exhibit in Norfolk, Va in 1907 and various Grange exhibits in 1908.

A curve in the road not taken: historiographic issues

The preference for “success stories” in history of technology is often seen as whiggish, and historians such as John Staudenmier have argued that more attention should be paid to the “roads not taken.”[12]

The fallacy of whig history, usually defined as viewing the past through the optics of the present, is that we fail to understand the past. The history of alternative fuels as written to date presents us with a similar problem. When an unsuccessful technology finally becomes successful, there is a danger of viewing the present through our misunderstanding of the past.

A focus on the success of petroleum technologies is evident in many histories of energy and automotive fuels that tend to exclude non-petroleum alternatives.[13] In recent years, ethanol production for anti-knock additives and straight fuel use (called E-85) has emerged as a major industry. US industry has the capacity in place or under construction for 12 billion gallons of ethanol per year, or about 10 percent of the overall gasoline supply. A similar capacity for ethanol and biodiesel is in place or under construction worldwide.[14] A variety of biodiesel technologies also emerged, with a 2006 production level of 250 million gallons and rapid increases projected there also. Alternative fuels, according to the New York Times, had come of age.[15] Thus, previous historical explanations based on the failure of alternative fuels are clearly antiquated.

We might note in passing that a lack of historical context has had modern policy implications. As noted elsewhere,[16] carbon neutrality and biodiversity are modern expectations by which we now tend to consider alternative fuels, but these yardsticks are flawed if we do not also take into account the original special motives that attended the birth of these technologies and that still impel their political trajectories.[17]

The discussion about motives for development of a technology must, to some extent, be tentative. Yet an exploration of inventors motives may give insight into the question of social construction versus determinism in history of technology. The deterministic view would hold that the intrinsic properties of a technology tend to follow a predictable or even inevitable path independent of social or political influence. The socially constructed view is that human action shapes technologies through conflicts and negotiations between social interests.[18]

In this situation, where technologies are nearly equivalent in attributes, it may be possible to observe this negotiation between social interests more closely. The alternative fuels in question -- alcohols and vegetable based bio-diesel -- are nearly equivalent with gasoline and diesel fuels. Although there are many specific differences, they are both combustible in the same types of engines and both groups fall into the same general price range for consumers. Yet the two groups have vastly different social and economic implications for the industries in question, and thus provide insight into the social interests that originally attempted to negotiate these technologies.

Ethanol and the rhetoric of the technological sublime

The cultural and political significance of alternative fuels goes far beyond the simple substitution of one ordinary product for another. Ethanol, biodiesel and other renewable fuels have long been seen in a broader symbolic context rather than simply a narrow technological one. Opponents have seen ethanol technology as a scheme for robbing taxpayers to enrich farmers, as a way to turn food for the poor into fuel for the rich, as compounding soil erosion problems, and as a marginally useful enhancement or replacement fuel for a transportation system that is poorly designed in the first place.

For advocates, ethanol has had the potential for revolutionizing agricultural economics, for dispelling city smog, and for curbing the power of the petroleum industry over the economy. In other words, ethanol was good for rural development, public health and national security. Proponents could also see in ethanol the potential to help strike balance between city and farm and the prospect of civilizing and humanizing industrial machinery. In addition, the idea that agriculture and biological resources could be primary sources of energy, the idea that humankind could live on solar "income" rather than fossil fuel "capital," has held a fascination for automotive and agricultural engineers, including Kettering and Ricardo, as we will see.

The literature of ethanol is filled with the rhetoric of the technological sublime, and no better example can be found than Alexander Graham Bell’s 1917 National Geographic article in which he predicts that alcohol will be the fuel of the future when the oil runs out. It “makes a beautiful, clean and efficient fuel…” Bell goes on to say: “Alcohol can be manufactured from corn stalks, and in fact from almost any vegetable matter capable of fermentation… We need never fear the exhaustion of our present fuel supplies so long as we can produce an annual crop of alcohol to any extent desired.”

This same level of rhetoric is graphically depicted in the symbolism used at the 1902 Paris alcohol fuel exposition. On the cover of the exposition's proceedings, a muse with an overflowing bouquet of roses looks down over the steering wheel with a confident smile. She is a portrait of wisdom and beauty, firmly in control of a gentle machine which seems appropriately located in some lush flower garden. (See Fig. 1 )

This rhetoric frequently attends the birth of any new technology, and of course there is nothing surprising about the high hopes of French automobile enthusiasts or Alexander Graham Bell. Their rhetoric was also probably a factor in the way automotive engineers viewed the technology. What is surprising, however, is the comparison between the rich historical record and the very poor modern understanding of the history of renewable energy.

HENRY FORD

Promoting the agrarian vision

The economic and political conflict between rural and urban interests is considered one of the most important dynamics of the 19^th and 20^th centuries, and populist agrarian movements were a major factor in US and European politics. The issue set was often seen in terms of balancing the agrarian values that might civilize and humanize industry against the use of technologies that could lift the burden of physical drudgery from rural life.

Henry Ford, a complex and not always attractive figure in American history, believed that the industrial revolution would eventually make the amenities of urban living available in rural areas. He saw a need for industry to decentralize and build small factories that would make a greater use of surplus agricultural products. This would bring about a better balance between urban and rural economies, he believed, and the United States would see “as great a development of farming as we have had in the past twenty years in manufacturing.” [19]

The son of a prosperous farmer who was said to dislike farm chores, Ford’s program to use technology to improve agriculture was described by historian Raynold Millard Wik in a Technology and Culture article in 1962. Ford tried all kinds of things, Wik said, “… to introduce scientific technology into American agriculture,” including “experiments to produce alcohol as a motor fuel by distilling it from farm crops.” When World War I threatened to create a gasoline famine, “he announced in 1915 that … the new Fordson tractor would be designed to burn alcohol as well as gasoline; thus the supply of fuel would be unlimited.”

Thus, Wik appropriately placed Ford and his interest in ethanol at the very nexus of this rural – urban contest, and also briefly noted that Ford tried to promote alcohol in 1920 and again in the 1930s. Yet Wik missed not only many additional facts, but also the broader context of a generation of “discontented agrarians” in Europe and the US that had similar aims. The competition between ethanol and petroleum was an arena where the competition between rural and urban interests played out, and Ford played a significant early role.

To step backward briefly: The history of alternative automotive fuels in the United States actually begins with Samuel Morey’s experiments in the 1820s,[20] but on a broad scale, it was the Civil War tax on beverage alcohol that pushed a booming industrial alcohol lamp fuel business into obscurity and (as agrarians argued) opened the door for the Pennsylvania oil boom.[21] In return, agrarians made it a high priority to eliminate this debilitating tax in the 1890s and early 1900s. (See Fig. 2).

Fig. 2 - Alcohol fueled German farm tractor around 1899. Courtesy of Roland Schnell,  “Bioethanol: Bereits vor mehr als hundert Jahren wurde Alkohol als Treibstoff genutzt,” Energiepflanzen Nr. 3/2006, Scheeßel-Hetzwege, Germany.   The alcohol fuels program in Germany at the turn of the 20^th century was the first to be supported by mandatory taxes and to be motivated by agrarianism and nationalism.   The program has a far-reaching influence on French, British and American farm movements. 

For example, in 1897 American agrarians noted that the European experience with free alcohol laws meant that an increase in the price of farm commodities and the opening of new markets in heating and lighting. [22] By 1905, it was common for Americans to read about German potato alcohol winning markets for farmers in a battle against the Standard Oil monopoly. [23] The German alcohol fuel program had started in the late 1890s with government prizes for research into engine and appliance use of alcohol along with financial support for new alcohol distilleries. In 1903, the Reichstag approved a tariff on oil to expand the farm alcohol production infrastructure. Potato alcohol was seen as the “final solution of the oil problem and the means by which the grasp of the great [Standard oil] monopoly will be broken.” [24] A network of small farm "Materialbrennereien" stills was put in place. Estimates of its size vary, but USDA put its 1903 production at 37 million gallons and by 1914, some 6,000 distilleries were said to be produced 66 million gallons of alcohol per year. [25] (In contrast, 1903 French industrial alcohol was at 10 million gallons per year and English was 3.7).

Of course, the idea of value-added agricultural processing, by which bulky crops are concentrated into more valuable products, is as old as moonshining. But the German program was politically innovative. The government was faced with two strong political movements: on the one hand, the agrarian movement, which wanted strong markets and high farm prices; and the political left on the other hand, which wanted cheap food for urban workers. When the German government brought agricultural products into industrial markets on a mass scale, it made agrarians happy while at the same time keeping food prices low.

Thus, German Kaiser Wilhelm found he could “satisfy the discontented agrarians” by encouraging the use of alcohol fuel from potatoes.[26] The oil industry was the only sector left out in the cold, and since Germany imported all of its oil, the agrarian movement was able to strike a nationalistic note. The lesson would not be lost on Henry Ford.

In the US, agrarians hoped that every American farmer could have his own supply of heat, light, and power at low prices, just like German farmers. “Advocates look forward with hope to a big change in the farmer’s life,” the New York Times reported. “If the law accomplishes what is hoped, it will . . . make a revolution on the farm,” the paper said. [27]

Agrarians found a strong ally in Theodore Roosevelt. The outspoken “trust-buster” bitterly attacked the Standard Oil’s monopoly in a variety of ways, and an alternative fuel was obviously a means of loosening Standard’s grip on the economy. As an alcohol tax relief bill passed the House in 1906, Roosevelt tried to rally Senate support in a letter to Congress:

“The Standard Oil Company has, largely by unfair or unlawful methods, crushed out home competition. It is highly desirable that an element of competition should be introduced by the passage of some such law as that which has already passed in the House, putting alcohol used in the arts and manufacturers upon the [tax] free list.” [28]

While alcohol could easily replace kerosene as a lamp fuel, just as kerosene replaced alcohol in 1862, the bigger question was what would happen with the new automobiles being developed. Before the final passage of the free alcohol bill, the Washington Post noted: “Henry Ford, the Detroit automobile manufacturer, is preparing to meet the new conditions with an automobile that will use the new fuel instead of gasoline.” Tests in Ford’s labs showed that 52-horsepower engines ran at 60 horsepower with alcohol as a fuel.[29]

The Senate passed the bill May 24, 1906, and the New York Times again noted the low cost of alcohol. "The new fuel and illuminant will utilize completely an important class of agricultural crops and byproducts thus benefiting in a double sense the farms and villages throughout the country," an editorial said.[30]

American enthusiasm for the new fuel increased even more when the German government shipped in 1907 “a comprehensive collection of apparatus employed in the production and consumption of denatured alcohol for the exhibition in Jamestown.” The 300^th anniversary celebration of the founding of Jamestown was opened by President Roosevelt and had, in the industrial alcohol section, a variety of German and American irons, coffee roasters, stoves, lamps and engines all running on alcohol.[31] This same exhibit, which had been in Paris and Italy in previous years, went on to tour fairs and National Grange meetings in the US until at least 1909.

As the nation’s largest farm organization, the Grange, was strongly Prohibitionist, since half of its voting members were women. In 1909, the Grange was divided in its support for denatured ethanol in fuel, with many purists believing that any support for distillers of alcohol would be a “deal with the devil.” As the debate unfolded, the pro-alcohol fuel faction was politically damaged by secretly taking money from distillers, and as a result, the farm community was no longer solidly behind the ethanol idea.[32]

Ford’s support continued. When Michigan’s state Prohibition law took effect in 1917, Ford said it would be “a shameful waste” to let the plants go idle. “Denatured alcohol can be used successfully as a fuel for automobile engines” Ford said.[33] Ten years later, Ford told a New York Times reporter that ethyl alcohol was "the fuel of the future" which “is going to come from fruit like that sumach out by the road, or from apples, weeds, sawdust -- almost anything. There is fuel in every bit of vegetable matter that can be fermented. There's enough alcohol in one year's yield of an acre of potatoes to drive the machinery necessary to cultivate the fields for a hundred years."[34] Throughout his life, Ford hoped that these kinds of developments would bring on “the greatest era of prosperity and happiness we have ever known.”[35]

Ethanol was not the only farm product that could be used by industry, of course. All kinds markets already existed, and the research needed to expand these markets was increasingly taken on by land-grant universities and the US Dept. of Agriculture by the 1930s. Targets for research included newsprint from Southern pine, milk into a silk-like fabric, desert shrubs into rubber, coffee beans into dyes, cornstalks into paper, and starch-laden grains into alcohol.

The general idea of adding value to crops by preparing them for industrial markets had no specific label until the 1920s, when Henry Ford’s Dearborn Independent newspaper published a lengthy article by William J. Hale urging the nation to launch a major alcohol fuel development program. In “Farming Must Become A Chemical Industry,” Hale explained an idea for a blend of science, economics, and philosophy which Hale labeled chemurgy—from the Egyptian word chem (from which “chemistry” is derived) and the Greek word ergon which meant “to work.” Hale said that the idea was to find new uses for farm crops and put chemistry to work for agriculture.[36]

With Ford’s backing, the Chemurgy concept moved quickly from an abstraction to concrete proposals for farm relief during the Depression. The parallel to the old German model for agrarian development seems clear. Chemurgy did not take off in the 1930s for a variety of reasons, especially because the administration of President Franklin Roosevelt was unhappy with Midwestern conservatives in general and Henry Ford and the Chemurgists in particular.[37]

In 1935, Ford sponsored a Chemurgy conference. The Farm Chemurgic Council organization was established to encourage research on farm products, and many ideas were explored at the conference. But the most explosive issue was ethanol as a fuel. Heated debates broke out as Chemurgists insisted that ethanol was technically feasible and economically beneficial. Oil industry representatives and their allies in the farm community argued that alcohol fuels were technically poor substitutes for gasoline and that there was no sense in making motorists pay for farm relief. Between the two warring groups there appeared little room for agreement. [38]

The Chemurgist proposals received a cool press reception. A New York Times editorial said: “Alcohol was glorified as a miracle-worker which would permanently place the farmer beyond the pale of distress. . . . [they] talked of alcohol at 10 cents a gallon—an impossible price even if corn sold for only half of what it brings now.” The editorial acknowledged that alcohol was technically a good fuel for high compression engines, but concluded that ideas about farmers making money by raising weeds for ethanol was nothing more than “Jules Verne dreaming.” [39]

Ford continued to support the Chemurgists, although as World War II opened, his agrarianism was overshadowed by his antisemitism and his support for German Nazi leaders. In 1937, a manufacturing company in Atchison Kansas was turned into an alcohol fuel plant. The new industry was beset by growing pains and hostility from the oil industry, and was never able to get on its feet.[40] (See Fig. 3). While the experience of producing alcohol proved of tremendous importance in creating synthetic rubber quickly in World War II, Ford’s farm Chemurgy movement died out by the 1960s.

Fig. 3.  Sales brochure for Agrol, a 10 percent ethanol – 90 percent gasoline fuel sold in the Midwest from 1937 – 1939 as part of an experiment backed by Henry Ford and others.  The Agrol plant was not financially successful but consultants from university agriculture and chemistry programs learned enough from its failure to mount a gigantic industrial effort in 1942.  The agrarian rationale for buying Agrol is clearly stated, as it is made from farm products. 

HARRY RICARDO

British nationalism and racing spirit

While agrarianism was a key motivation for Henry Ford, nationalism was another typical motivating factor for the development of alternative fuels technologies from the beginning of the 20^th century. Germany, as already noted, was a leader in challenging the oil industry with domestically produced alcohol fuel at the turn of the century, thus enhancing national security. The English government was also interested in ethanol for fuel but tended to be more cautious in embracing it. A committee on industrial alcohol formed in 1905 reported that the main question “would be one of price” and put off a full research program until later.[41]

At the time, very little was known about how fuel burned in an internal combustion engine, but a British engineering consultant named Henry Ricardo was determined to change that. Ricardo is best known today for his scientific development of the internal combustion engine in Europe and the US. His designs included the advanced Rolls-Royce airplane engines like the Crecy and the Merlin, considered the most efficient internal combustion engines ever built. In the 1920s and 30s, he was also known for the patented “Ricardo Discol racing spirit” – a type of alcohol fuel.

In 1913, Ricardo began testing samples of different petroleum and alternative fuels from around the world – the first methodical research in a laboratory setting. His program of research tended to be “concerned more with learning about existing fuels than improving them,” said S.J.W. Pleeth, chief chemist for the Cleveland Discol Co. “Of particular importance was his discovery of the anti-knock value of the alcohols, methanol and ethanol.”[42] And although it was not seen as terribly important at the time, “no single project has been of greater significance than the initial programme to investigate knock in the petrol engine,” his biographer wrote in 1968.[43]

Ricardo’s initial motives had to do with the lack of scientific information about engine knock and a nationalistic concern about British research. In his memoirs, Ricardo remarked that he was surprised in the pre-World War I years to learn how little research and development work was being carried out by British engine manufacturers, most of whom were paying royalties to German firms which were then using the royalties for research. “My friends all regretted that this should be so, for it both hurt their pride and limited their activities as engineers,” Ricardo wrote.[44] “Looking back over those years it seems shameful that we in England should have allowed ourselves to lag so far behind in the development of aeroplanes and engines, but it was lack of incentive, not ability, that brought this about,” he said.

World War I changed this picture dramatically, as French and British scientists actively researched military engines and fuels. Ricardo’s work focused primarily on the mechanical solutions to engine optimization. For example, he developed cross-head engine for the British tank corps in 1916 which “exhibits no-knock properties.”[45]

But the engine knock problem was not so easily solved, and the idea that oil would run out and that other fuels would be needed was so generally accepted that even a 1915 boys' book entitled Modern Inventions, devoted to zeppelins and submarines, had a chapter entitled "Alcohol Motors and the Fuel of the Future."[1][46]

An Alcohol Motor Fuel Committee was created in 1918, originally as part of the defense research effort. It was made up of representatives of the petroleum executive, the Home Office, the Admiralty, the Board of Agriculture and Fisheries, and others, including Ricardo. The committee was charged with considering sources of supply, methods of manufacture and costs of production for alcohol fuel.[47] Tests by various researchers found that mixtures of alcohol with 20 percent benzene or gasoline "run very smoothly, and without knocking.”[48] One researcher worked with London busses and said: "In all respects the [alcohol] fuel compared favorably with petrol [gasoline], and exhibited the characteristics of other alcohol mixtures in respect of flexibility, absence of knocking and cleanliness." The main finding of the research was that a large scale switch from petroleum was technically feasible. "We are fast squandering the oil that has been stored in the fuel beds, and it seems so far as our present knowledge takes us that it is to the fuels experimented with that we must turn for our salvation."[49]

Ricardo was involved with many of these engine and fuel experiments in one way or another. He tested fuels at various compression ratios up to the point where they would begin knocking, or what he termed the "highest useful compression ratio." Ethyl alcohol had a 7.5 value, with commercial gasolines then available at 4.5 to 6. He concluded that the low burning rate of alcohol lessens the tendency to knock, and that, using toluene as the reference point at 100 anti-knock, alcohol had a 130 rating – the highest of any other fuel – despite its drawbacks.[50]

In his seminal 1923 book, The High Speed Internal Combustion Engine, he said: “…It is a matter of absolute necessity to find an alternative fuel. Fortunately, such a fuel is in sight in the form of alcohol; this is a vegetable product whose consumption involves no drain on the world’s storage and which, in tropical countries at all events, can ultimately be produced in quantities sufficient to meet the world’s demand, at all events at the present rate of consumption. By the use of a fuel derived from vegetation, mankind is adapting the sun’s heat to the development of motive power, as it becomes available from day to day; by using mineral fuels, he is consuming a legacy – and a limited legacy at that – of heat stored away many thousands of years ago. In the one case he is, as it were, living within his income, in the other he is squandering his capital. It is perfectly well known that alcohol is an excellent fuel, and there is little doubt but that sufficient supplies could be produced within the tropical regions of the British empire…” [51]

Ricardo’s thinking seems to reflect a thread that is found among an earlier generation of inventors who feared the depletion of fossil fuels. Naval architect and inventor John Ericsson, for example, said: “The time will come when Europe must stop her mills for want of coal…. [Industry will move to the tropics] where an amount of motive power may be obtained many times greater than now employed by all the manufactories of Europe.”[52] And Augustine Mouchot, a French engineer, said: “The time will arrive when the industry of Europe will cease to find those natural resources, so necessary for it. Petroleum springs and coal mines are not inexhaustible but are rapidly diminishing in many places. Will man, then, return to the power of water and wind? Or will he emigrate where the most powerful source of heat sends its rays to all? History will show what will come.”[53]

These expressions of hope for a human destiny beyond fossil energy seem to have fallen out of fashion by the end of the 1920s. When a second edition of Ricardo’s book was issued in 1928, the fear of oil depletion had abated. Ricardo’s poetic paragraphs on renewable energy were redacted, and in their place was the following sober statement: “When we review the progress of mechanical engineering in the past we find that each new line of development starts with a period of experiment and groping, during which a wide range of types is evolved. By a process of elimination this range is very soon whittled down to one or two survivors; in the final choice of these survivors, chance plays often quite as important a part as merit. Ripe seeds of invention everywhere abound, and it awaits only a certain combination of need, of circumstance and, above all, perhaps, chance, to decide which shall germinate.”[54]

In 1921, Ricardo patented racing fuels called RD1 and RD2 (for Ricardo Discol) that contained methanol and ethanol, acetone and small amounts of water. These were widely used on race tracks throughout Europe and the US in the 1920s and 30s, but were regarded as a “pleasant foible” rather like the smell of castor oil around the race track.[55] Still, his advocacy of ethanol for general use was challenged in the 1920s by technical problems with alcohol production (such as the need for better azeotropic processing) and by the development of tetraethyl lead by Charles Kettering’s research group at General Motors.[56] As the technical problems cleared up, and ethanol blending could be more easily accomplished in the 1930s, Ricardo worked with National Distillers Co. and Shell Oil on an alcohol fuel blend called “Discol” that soon became very popular on a commercial level.[57] Ricardo’s Royal Society biography passed this over simply as 'racing spirit',[58] but it was certainly more than that. The formula was said to have “monopolized” racing fuels. Ads in the London Times boasted that “Racing Motors Run on Cleveland * Ricardo * Dicol.”[59] (See Figs. 4 and 5).

Hundreds of other advertisements and articles about Cleveland Discol, usually without mention of Ricardo or his patents, are found in the British newspapers and magazines from the 1930s until 1968. Cleveland Discol was historically the second-longest of any commercial alcohol fuel blending program in the world, with Brazil’s program being the longest-lived.

It is interesting that Ricardo continued to be involved with alternative fuels yet chose to give the issue little prominence. Perhaps S.J.W. Pleeth, a chemist for Discoll who might have work