378 years ago today, on August 22, 1647 (July 22, 1647 lunar calendar), French inventor Denis Papin was born. When you use a pressure cooker to cook steamed rice and save 1/2 to 4/5 of your time, can you think of the inventor of the pressure cooker? The inventor of the pressure cooker was French physicist, mathematician and inventor Denis Papin. Papin was born on August 22, 1647 in Blois, France. In 1681 Papin announced his first important invention - the "digestion pot", which was the original pressure cooker. It uses the principle that the greater the steam pressure in a sealed container, the higher the boiling point of water, and uses the high pressure and high temperature in the pot to quickly cook food, saving a lot of time. Papin used the "digestive pot" to cook the ribs like jelly, and invited members of the Royal Society to attend the "scientific dinner" to taste the power and results of the "digestive pot". Later, people used the "pressure cooker" instead of the name "digestive pot". Pressure cookers are effective in disinfecting and sterilizing bacteria in medical treatment. In high mountain plateau areas, pressure cookers are particularly useful because of the low air pressure and the low boiling point of water. Generally, the pot does not cook rice. In the paper industry, pressure cookers can quickly cook wood chips into wood pulp. In the food, canning and other industries, pressure cookers are also widely used. In 1681, Papin was elected as a member of the Royal Society. Later, he designed an engine powered by atmospheric pressure, but failed. Afterwards, he struggled in Italy, England, and Germany. It was not until 1687 that Papin received his official title at the age of 40: Professor of Mathematics at the University of Marburg in Germany. He was well aware that his knowledge was very useful in machinery, so he persisted in research and experimentation, and within a year invented a centrifugal pump for urban water supply and mine ventilation. In 1690, Papin studied the steam engine, did a lot of experiments, and published a paper on the expansion of steam to push the piston to move, and the subsequent condensation formed a vacuum. This paper became the principle of various gas engines since then. Papin combined the principle with practical application, hoping to use the steam engine to start a boat. He once made a small boat that used the steam engine to drive paddle blades through gears to replace the paddle, but was unfortunately damaged by a barge during experiments on the Fulda River in Germany. Thinking that London was a big port and needed new ships, Papin returned to London from Germany, when he was over sixty years old. At that time, a man named Sewell made a steam engine, and when it was exhibited at the Royal Society, Papin asked for it to be appraised. Papin proposed major improvements, but Sewell did not agree with the improvement. So Papin designed a new steam engine, which was ready to be used to run the ships. Papin spent his energy and income on scientific research. All his life, he was frugal and poor. He had to ask for the support of the Royal Society. He asked for £15 to improve the boiler. Tests would prove that Papin's steam engine was much better than Weill's. However, Sewell was powerful, lest Papin's experiment succeed, because then his steam engine would be worthless and lose his dictatorship. Therefore, Sewell thwarted in every way, resulting in the unreasonable rejection of Papin's reasonable request, a major invention was stifled in the cradle, and Papin died in disappointment, poverty, and obscurity in 1712, at the age of 65.