So someone believed so much in his latest invention that he gave up his job. Although this would not provide any satisfactory results for years to come, and in principle only survive in the memory of the inventor himself. Luckily, he remembered an existing machine and made significant improvements at it.

But slowly he was running out of money. There was luck in disguise in the form of the engineer Eugen Langen, son of a very successful sugar manufacturer. Langen had already earned money with his own ideas and was at least so enthusiastic about Otto's new creation, the atmospheric gas engine, that a small factory was set up in Servasgasse on the left bank of the Rhine in 1864 to manufacture it.

From the point of view of the history of the engine, which is perhaps even more important than the diesel, it makes little sense to deal with the three years of development time for the complicated mechanics, with which Langen was certainly a great help. The enormous financial expenditures, some of which carried out by third persons, should also remain unmentioned here.

We have already mentioned that the atmospheric gas engine was a great success, initially at the 1867 World's Fair. Due to the increasing number of orders, the company had to switch to the other side of the Rhine. Gottlieb Daimler was hired as head of production and Wilhelm Maybach as responsible for further improving the construction design.

But both had little to do with the move to the four-stroke engine. Daimler had its own solution in mind and Maybach even considered this to be unsuitable. It is not really known whether both initially rejected the attempts at the four-stroke engine. Apparently they were too far removed from the experiments, Daimler from Otto anyway, although they lived next to each other.

But the atmospheric gas engine had two important functions with regard to 'Otto's new engine'. Its success made the company great, and its decline in sales increased the pressure for a new invention. If you throw a piston in the air and basically only benefit from its return, then the expected performance is finite at around 3 hp.

Sure, an even larger piston and cylinder could have been used, but at the same time more height was needed, which was difficult with the already existing 3.5 meters. If you take more than one piston, the mechanical noises already described will probably be very annoying. The engine seemed, as it is, exhausted.

But it had a huge advantage and that also makes the origin story with the curling smoke, which Otto later spread, unimportant. All settings were based on the height of the piston rise. This is something like a performance adjustment. If it doesn't come high enough, it's not enough, if it hits against the top, you have too much.

For this reason, countless attempts had been made, and especially Otto did, with a filling that could be adjusted in quantity and mixing ratio in such a way that unnecessary excess power and a lack of safety during ignition were avoided. This also shows why this motor was superior to that of Lenoir in terms of efficiency.

Certainly some things broke during the direct conversion of the combustion pressure into the rotary movement, but ultimately the engine ran from 1775. It was thanks to Nicolaus Otto that he found a way out of the dilemma between the direct connection and the controllability of the mechanics. He did not necessarily have the approval of Daimler, who was still presenting plans for improving the old one at the time the new four-stroke engine was presented.

Although the new one didn't necessarily have more power than the old one at first, the enormous future potential increase in economy and performance was foreseeable. The construction drawings already took into account performances of up to 8 hp. Back then, who would have thought that in 2020, for example, there would be over a billion engines that work on the four-stroke principle.

So far, one of those involved has come up short, Eugen Langen (picture above). He seemed to be something like a cool head (Chairman of the Board) of the very rapidly developing company. He often had to mediate between the two different characters of Daimler and Otto. The latter also weakened because he felt that he was not recognized enough in the company.

Additional investors were needed for the enormous expansions. The father's inheritance after his death in 1869 enabled Langen and his two brothers to make considerable investments. Among other things, Gottlieb Daimler also secured permanent royalties as plant manager, which later facilitated the work on a significantly smaller version of the four-stroke engine together with Wilhelm Maybach.

Although Otto was commercial director, he only held 10 percent of the shares in the company, which only existed because of his ideas. Langen also thought it necessary to upgrade his position. Langen also thought it necessary to upgrade his position. He and his brothers gave up so many shares in favor of Otto that he got 21 percent. Later, Otto not only referred to him as a business partner, but also as his best friend.

Here is an advertisement from a later time. Otto had promised Langen that he would sufficiently publicly associate his name with the four-stroke engine. The slogan 'Otto's new motor' obviously also came from him. However, Otto also urgently needed support because a wave of patent challenges swept over him.

This is probably always the case and shows how highly the invention is valued. In some cases, lawyers have presented previous inventions or even publications, although their authors did not want to file any claims. In addition, companies that built the four-stroke engine with slight modifications had to be admonished, because the Deutz gas engine factory in Germany did not grant any patents.

Since the beginning of 1884, the patents on the four-stroke engine have been annulled. Interesting that Daimler's patent on its gas engine was granted in late 1883. After all, Germany already existed. And the patent for Benz's tricycle with a four-stroke engine dates from the beginning of 1886. Like Nicolaus Otto, Rudolf Diesel later suffered badly from the patent disputes too.

However, Otto also received incredible honors. There was the World Exhibition in Paris in 1878, where his engine surpassed all existing internal combustion engines in the world. And the honorary doctorate from the University of Würzburg in 1882, which he initially politely declined because he thought there were others more worthy than him, since he had only attended the 'Realschule' (secondary school). Finally, in 1946, the Association of German Engineers adopted the designation 'Ottomotor' as part of the German industrial standard.

And then he had managed to pull off another clou. Because he always wanted to make his engine more location-independent and switch to liquid fuel, he needed an electric ignition. He is credited with inventing the breakaway ignition, although others held the German patents. Preliminary work on the high-voltage magneto ignition is said to have taken place in the Deutz gas engine factory.

On this occasion, contact was made with Siemens and apparently they were also connected with Bosch. A man who later became very famous gave a guest performance for a good two years from 1907, Ettore Bugatti. He had been hired to set up automobile production with the four-stroke engine. But, his approaches were too expensive for the superiors in Deutz.

Yes, one made much money with the production of four-stroke engines, paying dividends of up to an incredible 95 percent. After just five years, the performance, e.g. as a two-cylinder, had increased more than tenfold. Now the engine was slowly becoming interesting for larger applications, e.g. the generation of electricity. The picture of Cologne Cathedral, which was lit up by a four-stroke motor at the inauguration in 1880, still hangs in the Deutzer Museum today.

All that remains is to report about separations. At some point things couldn't go any further with Daimler: termination of contract in mid-1882, good severance pay, but also a temporary ban on working in the area previously worked on. It is said of Maybach that he might have stayed if he had been asked. Today we know that Daimler did not necessarily comply with the conditions.

Nicolaus August Otto died in 1891, barely surviving Gottlieb Daimler, and Eugen Langen four years later. Apparently there is a memorial for both of them in Deutz with the four-stroke engine on a plinth in front of the train station. The local vocational college, only for automotive students, also bears his name. But the engine, with its various developments, deserves its own chapter. And Otto's son Gustav appears in the chapter about BMW.