Pyréolophore
Further development
Further development
-------------------

On 24 December 1807, the brothers reported to [Lazare Carnot](/wiki/Lazare_Carnot "Lazare Carnot") that they had developed a new, highly flammable fuel (powder) by mixing one part resin with nine parts of crushed coal dust.

In 1817 the brothers achieved another first by using a rudimentary [fuel injection](/wiki/Fuel_injection "Fuel injection") system.[The Pyreolophore at photo\-museum.org](http://www.photo-museum.org/pyreolophore-invention-internal-combustion-engine/) Accessed 5 July 2017

By 1817 there was insufficient progress to attract subsidy and investment, so the ten\-year patent expired. Worried about losing control of the engine, Claude traveled first to Paris and then to England in an attempt to further the project. He received the patent consent of [King George III](/wiki/George_III_of_the_United_Kingdom "George III of the United Kingdom") on 23 December 1817\. This was not the key to success. Over the next ten years, Claude remained in London, settled in [Kew](/wiki/Kew "Kew") and descended into [delirium](/wiki/Delirium "Delirium"), whereby he squandered much of the family fortune chasing inappropriate business opportunities for the Pyréolophore. Accessed 5 July 2017 Nicéphore, meanwhile, was also occupied with the task of [inventing photography](/wiki/History_of_photography "History of photography"). Accessed 5 July 2017

### Design flaw

In 1824, after the brothers' project had lost momentum, the French physicist [Nicolas Léonard Sadi Carnot](/wiki/Nicolas_L%C3%A9onard_Sadi_Carnot "Nicolas Léonard Sadi Carnot") scientifically established the [thermodynamic](/wiki/Thermodynamic "Thermodynamic") theory of idealized heat engines. This highlighted the flaw in the design of the Pyréolophore, whereby it needed a compression mechanism to increase the difference between the upper and lower working temperatures and potentially unlock sufficient power and efficiency.


Why did the ten-year patent for the Pyreolophore expire?