6. Etienne Lenoir proved internal combustion engines were practical
The internal combustion engine was developed in experimental form in the first decade of the 19th century, but there were no commercial applications for it until 1858, when Frenchman Etienne Lenoir patented a working version of the technology. Lenoir used the engine in automobiles and boats, though its primary use was as a stationary engine, providing power to printing presses, looms, and other manufacturing machinery. His demonstration of the viability of the internal combustion engine led to the growth of the automotive and oil industries, as well as the use of internal combustion engines in a wide variety of applications.