But what did she ask for?

“Ligroin”. This was heavy naptha, a distillate of petroleum oil used as a solvent, and it had been on the German market from around the 1860s.

It was rather different from the petrol you buy today. The classically educated British called it petroleum, which comes from the Latin: petra; rock, oleum; oil or literally rock-oil.

This was appropriate as petroleum was found under sedimentary rocks where countless bodies of zooplankton and algae had been subjected to enormous pressure and heat. It was fossilised fuel (and the energy was fossilised sunlight).

The first modern oil well wasn’t in Texas or Saudi Arabia, but at the Riddings colliery at Alfreton, Derbyshire. In 1847 a chemist, James “Paraffin” Young noticed a seepage of oil and managed to distil from it a light oil that he could use in lamps instead of expensive whale oil.

His patented discovery probably saved whales from total extinction. Different fractions of the distilled product were useful for different things: paraffin for lamps and the more volatile petrol as a solvent or fuel.  

The Americans called the fuel gasoline, or confusingly “gas” for short, a name which comes from the British coffee merchant and Temperance publisher John Cassell. Seeing new opportunities for artificial light, in 1862 he set up an oil refinery in Hanwell, London and marketed his new lamp fuel under his own name:

“The Patent Cazeline Oil, safe, economical, and brilliant … possesses all the requisites which have so long been desired as a means of powerful artificial light.”

The Times, 27 November 1862

Sales boomed, then fell away in Ireland. Cassell found out that a Dublin shopkeeper, one Samuel Boyd, was selling counterfeit Cazeline Oil and asked him to stop. The shopkeeper responded with a paintbrush, changing every label to read “Gazeline”, coining a word that eventually spread throughout the USA. Cassell took him to court and won, but Boyd’s coinage won in the end: “gasoline”.

So the Americans called the fuel gasoline, or confusingly “gas” for short.

Karl Benz knew that his engine had a limit, and that limit was called detonation. Combustion in petrol engine is initiated by the sparking plug at a specific point in the piston’s travel; between 0 to 40 crankshaft degrees before the piston comes to the top of its stroke (Top Dead Centre).

The flame front should spread smoothly, burning all the fuel/air mixture just in time to push the piston back down the cylinder. But when pockets of fuel/air mixture explode early detonation occurs. The shockwave causes the characteristic knocking or pinging sound as combustion pressures rise sharply.

The results can be disastrous: first overheating and then the erosion of holes in the piston or cylinder head. Old-time engineers could detect the onset of detonation by holding a short piece of steel between their teeth and resting the other end on the cylinder head of an engine running at full throttle.

That’s why they didn’t have many teeth.

When used in Benz’s engine ordinary chemist’s shop petroleum worked well enough until the engine’s compression ratio was increased beyond around 3.2:1. This ratio is a measure of how tightly the fuel and air mixture is squeezed in the cylinder.

More accurately it is the ratio between the volume of the cylinder plus the combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke.

If Benz’s one-litre (actually 954cc) cylinder drew in a deep breath of one litre of air/fuel mixture it could safely compress it to only a third of the volume. Any higher ratio and detonation would set in.

Modern car engines use a compression ratio of around 10:1 because there are huge gains in power and thermal efficiency to be had.

The Rolls Royce Silver Ghost made around 48 horsepower from over 7 litres, a pitiful 6.8 hp per litre, whereas a modern General Motors LS 7 litre engine of the same capacity, with an 11:1 compression ratio, makes 505 horsepower.

That’s 72 hp per litre, or more than ten times as much. A lot of the difference has to do with the advances in fuel because they enabled higher compressions to be used.

Fuel quality was therefore of vital importance to the motor industry once it was known how much more power could be had.  How could they improve the fuel? Petrol’s resistance to detonation is measured in octane number: the higher the octane number the more compression the fuel can withstand before detonating.

Benz Patent-Motorwagen would have been running on Ligroin of about 40 octane, and during the First World War, aircraft engines would have used petrol of around 50 octane. But petrol bought in a supermarket petrol station today might have an octane rating of 95 or so. 

And if the octane number is increased from 72 to 100, the power is likely to increase by 100 per cent.

Low-octane fuel nearly brought disaster to the Allies during the First World War. Before the American entry into the war, their European Allies used petrol distilled from crude oils from the Far East which gave acceptable performance in their aircraft engines.

When the United States entered the war in April 1917 the U.S. became responsible for supplying petrol to the Allies and suddenly a decrease in engine performance was noticed. Engines gummed up and sparking plugs fouled. If full throttle was used detonation set in and a number of aircraft were lost.

Panicked messages were sent across the Atlantic and it was found that petroleum from aromatic and naphthenic base crude oils was superior. These came from California, South Texas, the Mexican Gulf and Venezuela.

Exotic fuels were cooked up for the Schneider Trophy Rolls-Royce R engines by Rodney Banks, a British fuel chemist working for the Anglo-American Oil Company. The winning engine of 1929 ran on 78% benzol, and 22 % Romanian petrol with a dash of tetraethyl lead, and it developed 1900 hp with high supercharger pressures.

In 1931, when the Trophy was won for perpetuity, the fuel chemists concocted a brew for a world speed record attempt consisting of 60% methanol, 30 % benzol and 10 % acetone, and the Rolls-Royce testers were able to screw up the supercharger pressure to make a staggering 2530 hp.

These exotic brews were impracticable for military use, being expensive and unstable. Petroleum had to be made with a higher octane rating, and this is where Thomas Midgley Jr. comes into our story. 

Midgley was an American engineer working for General Motors whose assistants T.A. Boyd and Carroll A. Hochwalt undertook the first tests of tetra-ethyl lead (TEL) in 1921. They discovered that adding tetra-ethyl lead (TEL) to petrol prevented, or at least delayed the onset of detonation or knocking in engines.

His team had an engine on the test rig running under detonating conditions when suddenly

“The ear-splitting knock of their test engine turned to a smooth purr when only a small amount of the compound was added to the fuel supply. and all the men danced a non-scientific jig around the laboratory.” 

Thomas Midgley Jr.quoted in Nickerson, Stanton P., “Tetraethyl Lead: A Product of American Research,”

Midgley took the credit, writing to his old professor:

“We have recently discovered a new antiknock material approximately 50 times as powerful as aniline and which proves to be 100 % practical and commercial. In fact, our wildest dreams of success on this problem are exceeded by this new material. ‘Allah is good.’”

Letter, T. Midgley to Prof. H. Diederichs. Dec. 14, 1921. T

The TEL certainly increased the octane number. The problem was this compound was highly poisonous and they knew it. Indeed, it had killed several German scientists who had experimented with the stuff. (source: jalopnik)

All mention of lead was omitted from publicity materials, but Midgley became ill from lead poisoning. He had to drop all his work in 1923 and take a long vacation in Miami.

General Motors created the Ethyl Corporation and built a plant in New Jersey to mass produce the stuff. Workers suffered hallucinations, insanity and five deaths.

To prove his compound was safe Midgley participated in a press conference in 1924 at which he poured TEL over his hands, placed a bottle of the chemical under his nose, and inhaled its vapour for 60 seconds, declaring that he could do this every day without succumbing to any problems.

Shortly afterwards he had to take an absence from work again after being diagnosed with lead poisoning. The State of New Jersey ordered the plant to be closed a few days later.

Still, the profit motive prevailed and what little regulation there was in the US was ineffective. TEL was manufactured and spread worldwide as a constituent of high-octane petrol, releasing large amounts of lead into the atmosphere and causing countless cases of brain damage, particularly among children.

Not content with that, Midgley was on the General Motors team that invented Chlorofluorocarbons (CFCs) for air conditioners and refrigerators under the name of Freon, which was later implicated in the destruction of the ozone layer of the atmosphere.

Once again Midgley flamboyantly demonstrated the safety of his lethal brew, this time in front of the American Chemical Society, by inhaling a breath of the gas and using it to extinguish a candle.

Midgley was highly decorated for his work before it was discovered to be so diabolical, and he was duly elected the president and chairman- of the American Chemical society.

Midgley has been described as the single organism that has had the most negative impact on the world’s atmosphere, ever, and Bill Bryson wrote in 2003 that he possessed “an instinct for the regrettable that was almost uncanny.” 

Environmental protests prevailed and after lead in petrol was banned a 2011 study by the California State University found that

“ridding the world of leaded petrol … has resulted in $2.4 trillion in annual benefits, 1.2 million fewer premature deaths, higher overall intelligence and 58 million fewer crimes”.

California State University

Once again, thanks to scientists and experts who spotted the ozone hole caused by CFCs, another Midgley menace was eradicated. In 2007, 200 countries agreed to eliminate hydrochlorofluorocarbons entirely by 2020.

Synthetic fuel might become important in the future, and might delay the extinction of the piston engine. Porsche, like all other conventional car manufacturers, has a huge vested interest in the piston engine.

The company is planning to produce their own synthetic fuel in Chile on an industrial scale, using wind power to make the stuff. Porsche’s boss Frank Walliser explained:

“The general idea behind these synthetic fuels is that there is no change to the engine necessary….It has no impact on performance – some horses more, so it’s going in the right direction – but emissions are way better; we see less particles, less NOx…In a well-to-wheel consideration, it is on the same level as an electric car.”

Frank Walliser, Porsche

A piston engine on the same level as an electric car? That’s quite a claim, and it may take a few years to work out the true costs.

The question remains: where now for gasoline-powered vehicles?

The Decauville company was well known for making light railways, but had diversified into making the new Motor Car. This had been invented by Karl Benz in 1888, and popularised by his wife Bertha Benz on her famous road trip of that year.

The Decauville Voiturelle

Decauville’s first Voiturelle was well received on the French market in 1898. The little car had a tiny single cylinder engine under the seat, and this motor was made by De Dion-Bouton, a partner French car manufacturer that Decauville had made 3,000 tricycle chassis for.

It had no roof, just a padded seat perched on top of a four wheel chassis. There was room for three occupants, it weighed just 425 lbs (192 kgs) and sold for 3,500 francs- about $17,000 today (source: wikipedia).

The Voiturelle had a kind of sliding-pillar independent front suspension – quite possibly the first in motor car history – but no suspension in the rear! And it was steered by a tiller, not a wheel. But this little car was a good beginning.

Then a new twin-cylinder 5hp Decauville was released towards the end of 1899, propelling the Decauville into a whole different market. It was designed by Decauville’s Ravenez and Cornilleau. Soon the engine power was increased to 10hp.

The Racing Decauville

The engine in the new car was now mounted at the front instead of under the seat, and was water-cooled instead of air-cooled. The two-cylinder engine of 765cc, with a bore of 80 and a stroke of 76mm drove the rear wheels through a Bozier gearbox with only two forward speeds and one reverse. And a wheel was fiited for steering instead of the tiller.

Now there was suspension at the rear, with semi-elliptic fore and aft leaf springs together with a transverse semi-elliptic spring, suspending the previous Voiturelle’s rear axle. And at the front, like the previous Voiturelle model there was a transverse leaf spring and sliding pillars.

The chassis was made of tubes and the rear axle design of the earlier Voiturelle was adopted. But the body looked different, with a round bonnet and a radiator on the dashboard! That must have helped with cold fingers.

It weighed twice as much as the earlier car, 992 lbs (450 kilos) and cost nearly double at 6,500 francs ($31,000 today). But it was a much better car, as racing events would soon go to show.

Decauville won first in class in the Paris to Amsterdam Race of 1898 over 969 miles, then an amazing 1-2-3 result in the Tour de France in 1899 over a demanding 1,450 miles, and first place in the Coupe des Voiturelles in the Paris-Rouen-Paris event in 1900. Decauville also took the Daily Mail prize in the 1900 English Thousand Miles Trial.

Careful design and precision engineering had paid off. Briefly, Decauville were considered the best car on the market (source: bonhams.com).

The Decauville gets an admirer…

Meanwhile, in England, Henry Royce was the rather shy engineer owner of Royce Ltd, a Manchester-based engineering company making dynamos and electrical gear.

The end of the Boer War had caused an economic downturn, and cheaper foreign-made dynamos appeared on the market using Royce patented designs without paying him any royalties. Sounds familiar today?

So Royce either had to make his own products more cheaply or diversify by making a new product. As a perfectionist, the first course would have been anathema to him, and at around the turn of the century, he saw clearly that the new Motor Car was the next big thing. And it would be ideal for his business: precision engineering.

Royce first bought a De Dion-Bouton car to examine and then looked for another make. The Continent was in the forefront of car manufacturing at that early stage, the French in particular.

So then, the story goes, Henry Royce bought a 1902 Decauville with a 10 hp two-cylindered engine. This was the model that had been so successful in races and reliability trials. But Royce thought the engine vibrated too much and this offended his perfectionist instincts.

He was dissatisfied with other aspects of the Decauville, so in typical Henry Royce fashion he dismantled it, inspected the parts, made improvements and then built his own motor car.

An aristocratic car salesman, the Honourable Charles Rolls was on the lookout for an engineering company that could build him a new make of British car. When Mr. Rolls met Mr. Royce in Manchester both men found the man they had been looking for.

Rolls had been hunting for a British-built replacement for the French-built cars he had been selling to his wealthy acquaintances, and Royce needed a buyer with connections to the rich and famous for his perfectly-made but expensive machines.

Rolls deplored the lack of quality British car manufacturers and was on the look-out for a suitable car. What he found at Royce’s was a revelation. Although he disliked two-cylindered engines and had been looking for a three-or-four-cylindered car the smooth running of the two-cylindered Royce convinced him that here was a machine he could sell under his own name.  

So goes the Rolls-Royce legend.

But if the Decauville was so bad why was there so much of the French car in the genes of the Royce car? The radiator looked so similar that when Charles Rolls saw the car for the first time he thought it was a product of the French factory. The rest of it looked much the same.

So was the Decauville the second-best car in the world?

Henry Royce’s approach had always been to “take the best and make it better”, which later became the central Rolls-Royce mantra. And so he had set about doing exactly that: copying what worked on the Decauville, improving what didn’t.

As Royce once said himself, inventors and pioneers rarely make any money, only those who take their ideas and make them work.

He was a modest man, who always described himself as a mechanic. But where another car maker would use just a rivet, Royce would use a tapered bolt and nut.

“In 1904 he had produced the first Royce car: this was before he met the late Hon. C.S. Rolls,” wrote his friend Frank Lord “The car was a 10 hp. two-cylinder, and was a revelation for its date, having properly lubricated joints to the drive shaft [instead of chains].

As he could not buy a satisfactory coil for the ignition, he designed one, fitting very large points of the purest platinum, which, although expensive in the first place, never seemed to want adjusting or cleaning. The coil itself was as nearly perfect as possible, thus from the very first making the car reliable in a part in which, with most cars, there was endless trouble.”

Frank Lord Henry Royce obituary, Autocar May 1933

When the two friends took the car out for an ambitious run in Wales, the famous Royce reliability shone through:

“During the whole three days’ trial we never had a stop of any sort from any fault of the car, a pretty good performance for a car designed by a man who had never designed one before; yet only what you could expect from one designed by Mr. Royce.”

Frank Lord op cit

Decauville – the legacy

On a personal note, my old school friend Trevor Ellis owns a Decauville Reg no. FP4 which was the first car registered in the county of Rutland with FPs1,2 and 3 being allocated to motorcycles for the post office. In 2022 it completed the London to Brighton Run and was awarded President’s choice at the Concours D’Elegance at St James Palace on Saturday prior to the run.

Rolls-Royce cars, built with Henry Royce’s painstaking precision soon became known as “The Best Car in the World”, but few knew or cared how much a little French car had contributed to their success.

The parent company stopped making cars in 1909, and so the Decauville disappeared into history.

But the little French car had inspired one of the most important collaborations in the history of the motor industry: Rolls. And Royce.