I chose to present you a work concerning cars because it is about my biggest passion and because my dream is a day to be able to have in my ownership a sports car
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- 2.B.c)Improvements and modifications
- 2.C)The arrival of the Diesel
- Gasoline engine cycle (four-stroke)
| 2.B.b)Internal combustion engine:
The first gas engine was realized by the German Nicolaus Otto in 1876. Then, came the gasoline engine in 1889, the first one built to be mass-produced was invented by Gottlieb Daimler, and the first car with a gasoline engine invented to be mass-produced was born thanks to the association of René Panhard and Emile Levassor under the Bachelor's degree of production of Daimler in 1891. This car was the Panhard-Levassor. 
In the XXth century, France is really at the forefront of the car industry. A large number of car industries are born as Delahaye, Mors and Gladiators, Renault, Darracq, Rochet Sneider... Not less than 600 manufacturers is divided the world market. On the eve of the World War I, there is two trends. The luxury automobile, the custom-made car according to the desires of the customer and the popular car, made in series and in the chain as the automobile giant Ford who produced his model T in several million copies. This event is really going to contribute to the democratization of this means of transportation.
In fact, we built some internal combustion engines from the beginning of the XIXth century, before the oil becomes a product of common use. We used then for these engines vapors of turpentin or some hydrogen. But it was only with the gasoline, the only liquid vaporizing easily, at the same time combustible and available in great quantities. The first usable internal combustion engine was built in 1860 by the French inventor Étienne Lenoir, who took up it in a small cart, a first car without horses. In 1876, the German technician Nikolaus August Otto, who had heard about the engine Lenoir, built a four-stroke engine. In the first time, a piston closely adjusted in a cylinder is pulled towards the outside, so as to inhale a mixture of gasoline and air in the empty cylinder. Then the valve is pushed away in the cylinder to compress gases. In the point of maximal compression, gases are fired and explode. The explosion pushes away the valve, and it is this movement which makes turning the engine. It pulls a wheel which puts back again the valve to expel from the cylinder the residues after combustion or the exhaust gas, the fourth and last time of the cycle. The wheel again makes take out the piston it establishes the beginning of the following cycle. A Scottish engineer, Dugald Clerk, found almost immediately an improvement in the four-stroke engine. He added the second cylinder, arranged so that his piston is pulled by the explosion as the other one was in the time of admission: this arrangement returned the much more regular flow of energy. Later, the addition of the other cylinders (four is a current number today) increased the regularity and the power of this internal combustion engine. Such an engine turned out essential in the practical realization of automobiles, but auxiliary inventions were also imperative. The ignition of the mixture of gasoline and air at the right time raised a difficult problem. We used for it any sorts of ingenious devices. By 1923 he became common to recover to it to an electric system. The food results from a battery which supplies the electricity resulting from a chemical reaction. But here we can reload drum kits by making them cross by an electric current of sense opposite to that of their discharge; this current knocks down the sense of the chemical reaction and chemicals can then supply with the electricity. The current opposite is brought by a small generator which pulls the engine. The most common type of storage drum kit has an alternation of lead plates and lead oxide, soaking into a solution relatively concentrated by sulphuric acid. It was invented by the French physicist Gaston Planté in 1859 and put under his modern shape by the American electrical engineer Charles Francis Brush in 1881. We invented since more strong and more compact accumulators, for example an accumulator nickel-iron realized by Edison by 1905, but from an economic point of view, none can compete with the lead-ion battery. The voltage supplied by the drum kit is stored in the magnetic field of a transformer called induction coil, and the rough fall of this field supplies the headland of tension producing the spark between the electrodes of the spark plugs which are familiar to us. When an internal combustion engine started, the slowness maintains it in movement between driving times. But it is necessary to supply it with the energy to make it start. At the beginning, it was made in the hand (with the crank of the automobile), and we again make start in the hand outboard motors and lawn mowers by firing at a thread. The crank of the automobile, it, required a well developed arm muscle. When the engine began to turn, it was rather frequent to see the crank escaping the hand which held it, to turn and to break the arm of the operator. 
2.B.c)Improvements and modifications: In 1912, the American Charles Franklin Kettering invented a starter which allowed to finish it with the crank. The starter is fed by the drum kit which supplies the energy necessary for the first tours of the engine. It was two German engineers, Gottlieb Daimler and Carl Benz that built independently in 1885 the first automobiles of practical use. But what made of the automobile a usual means of transportation, it was the invention of the mass production. The first one to implement this technique was Eli Whitney, who deserves more fame for it than for its most famous invention of the machine to shell the cotton. In 1789, Whitney signed a contract with the American federal government for the supply of rifles to the army. Until this period, rifles had been made one by one, each with the own rooms. Whitney designed standard spare parts, so that a given part, can adapt itself to any rifle. This simple and only innovation, a standard of manufacturing, exchangeable spare parts for a type given by product, was maybe so important as any other factor in the creation of the modern industry of mass production. When powerful machines were available, they allowed to make parts standardized in practically unlimited number. The American engineer Henri Ford, the first one, went up to the end of this concept. He had built his first automobile (one two cylinders) in 1892, then had gone to work for Detroit Automobile Company in 1899 as chief engineer. The company wanted to produce custom-made cars, but Ford had other intentions. He resigned in 1902 to produce automobiles in his account, in quantity. In 1909, he began to produce the model T, and by 1913, to make it according to the method of Whitney: a car after the other one, each identical to the previous one, and all with the same spare parts. Ford understood that he could accelerate the production by using workers human as we used machines, to make the even small work in a repetitive way continuously. The American Samuel Colt (who had invented the revolver or "six-shot gun") had put the first ranging-poles of the method in 1847, and the car manufacturer Ransom E. Olds had applied the system to the engine of automobile in 1900. However, Olds lost its financial supports, and he thus fell to Ford to bring to a successful conclusion the project. Ford designed the chain, with workers adding parts to the assembly while this one passed in front of them on bands of transport, until the ended car leaves the chain by driving. Two economic progresses resulted from this system: of high salaries for the workers, and cars which we could sell to strangely low prizes. By 1913, Ford built one thousand T models a day. When the chain was stopped in 1927, we had produced fifteen million cars and the prize had fallen to 290 dollars. The craze for the change of vehicle every year took it then, and Ford was forced to join the upholders of the variety and the superficial novelty, which made increase enormously the prize of automobiles and lose to the motorists a big part of the advantages of the mass production. 2.C)The arrival of the Diesel: In 1892, the German mechanical engineer Rudolf Diesel introduced a modification in the internal combustion engine, which was simple and economic by running. He(it) carried(wore) the mixture high-pressure fuel-air, so that the heat of the only compression was enough to fire him(it). The diesel engine makes possible the use of fractions of distillation of the oil with higher boiling point which doesn’t rattle. Because of the highest used compression, the engine must be more solid. That’s why diesel engines are heavier than those with gasoline. When an adequate system of injection of the fuel was worked out in the twenties, it began to stand out for trucks, tractors, coaches, boats; he is now undisputed king of the heavy transport. Improvements of the gasoline still increased the efficiency on the internal combustion engine. The gasoline is a complex mixture of molecules made by atoms of carbon and by hydrogen (hydrocarbons), of which some burn faster than with others. A speed of too fast combustion is to be avoided, because then the mixture gasoline-air explodes too places at the same time, producing the jingle. A lower speed of combustion produces an equal dilation of the vapor, which pushes the piston regularly and effectively. The rate of jingle of a given gasoline is measured by its octane rating, compared with the jingle of one hydrocarbon conscript iso-octan, which produces very few jingles, mixed in the normal heptan, which produces it a lot. One of the main purposes of the refining of the gasoline is to make a mixture of hydrocarbons with a high octane rating. We designed engines of automobiles with more and more raised compression ratios, it means that the mixture gasoline-air is compressed in bigger densities before the ignition. This compression allows more extracted energy of the gasoline but also encourages the jingle, so that it is necessary to make some gasoline with more and more raised octan rating. To simplify the task, we use chemicals which, when we add them in small quantity to the gasoline, it reduce the jingle. The most effective of these compounds anti-jingle is the lead tetraethyl, a compound of the lead the properties of which had been noticed by the American chemist Thomas Midgley and which we used for the first time in 1925. The gasoline which contains it is called high-octan petrol. If there was only some lead tetraethyl, lead oxides formed during the combustion of the gasoline would dirty and would destroy the engine. This is why we add some bromide of ethylene. The lead atom of the lead tetraethyl harmonizes with the atom of bromine of the bromide of ethylen to form some lead bromide which, in the temperature of combustion of the gasoline, vaporizes and is expelled with exhaust gases. Diesel fuels are tested, as regards time passing by between compression and ignition (to avoid a too long time), compared with one hydrocarbon conscript cetan, the molecule of which contains sixteen atoms of carbon, while that of iso-octane contains only eight. For diesel fuels, we thus speak about index of cetan. The improvements continued. In 1923, it was tires low pressure, at the beginning of the fifties tires without inner tube, that returned the less frequent explosions. In the forties, cars had air conditioning in the United States, then the automatic transmissions were introduced and gear changes began to be less used. Towards the fifties appeared the direction and the assisted brakes system (ABS). The automobile became a so intrinsic part of the modern life as in spite of the increase of the cost of the gasoline and the atmospheric pollution, it seems impossible, with the exception of a disaster destroying the humanity, as it disappears. Gasoline engine cycle (four-stroke): 
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