Karl Benz patents the automobile

On 29 January 1886 a small Mannheim engine maker, Benz & Co., asked the Imperial Patent Office in Berlin to protect a 'vehicle with gas-engine drive'. The patent, No. 37435, was printed on 2 November 1886 and counted from the January date. Its drawings show a light three-wheeled carriage for two people, driven by a small engine at the back that made its own fuel gas from ligroin, a light petroleum spirit sold by chemists, and kept its cylinder cool by boiling off water. This was Carl Benz's Patent-Motorwagen, or patent motor car: not a coach with an engine added, but a new machine designed around the engine, with a frame of steel tubes, wire wheels, one cylinder lying flat, a big flywheel turning flat behind the seat, and a belt and chains to the rear wheels. It gave less than one horsepower; later versions reached about 16 kilometres (10 miles) an hour.

Benz, born in 1844 near Karlsruhe, the son of a railway engine driver, was a trained mechanical engineer who had long wanted to build a 'horseless carriage'. First he needed an engine and money. His two-stroke gas engine first ran properly on New Year's Eve 1879, and its sales let him found Benz & Cie. in Mannheim in October 1883 with two businessmen who sold bicycles, Max Rose and Friedrich Wilhelm Esslinger. For the car he turned to the four-stroke principle, whose Deutz patent had been partly struck down in 1884, and built a smaller, faster engine. He finished the car in October 1885, tried it in the works yard and on dark early-morning streets, and drove it in public on Mannheim's Ring road on 3 July 1886. The local paper reported it, but almost nobody wanted one. Less than a hundred kilometres away, in Cannstatt near Stuttgart, Gottlieb Daimler and Wilhelm Maybach had built their own fast petrol engine and put it on a wooden two-wheeler in 1885 and in a horse carriage in 1886. The two teams worked apart; Benz later said he never once spoke to Daimler.

What the car still lacked was proof that it was useful. At dawn on 5 August 1888 Bertha Benz, who had put her dowry into her husband's business, took the improved Model 3 without telling him and set off with their sons Eugen, 15, and Richard, 13, to visit her mother in Pforzheim, about 100 kilometres away. It was the first long journey ever made by car. She bought ligroin at the town pharmacy in Wiesloch, cleared a blocked fuel line with her hatpin, fixed the ignition with her garter, had a blacksmith mend the chain and a cobbler put new leather on the brakes, and pushed the car up the hills. After about thirteen hours they arrived, and a few days later they drove home. Her report led Benz to add a gear for climbing hills. In September he showed the car at the Munich engineering exhibition, drove it through the city several times a day and won the top gold medal. The Model 3 became the first car built in series for sale, at 3,000 marks, and in France the engineer Émile Roger took over the selling.

Sales stayed slow for years, but Benz kept improving his design: four wheels with proper steering in 1893, then the light and cheap Velo of 1894, of which about 1,200 were built, and by 1900 Benz & Cie. was the largest car factory in the world. In 1926 it joined Daimler's company to form Daimler-Benz, the maker of Mercedes-Benz cars. Patent 37435 is often called the birth certificate of the automobile, and in 2011 UNESCO added it to its Memory of the World register. The original car went to the Deutsches Museum in Munich in 1906 and is still on show there, and Bertha's road is signposted today as the Bertha Benz Memorial Route. Every petrol car since has the same basic parts that Benz first put together as one design: engine, fuel supply, ignition, cooling, gears and brakes.