"Flying machines heavier than air is impossible!" - once said a famous mathematician, and after only a year and a half broke away from the ground the first plane of the Wright brothers. And this is just one of many examples of technological progress that does not stop for a minute. So, the simple knife was replaced by a food processor, the fan was replaced by an air conditioner, the broom was improved to a vacuum cleaner. Today we are surrounded by so many different devices and mechanisms that we can no longer imagine our lives without all these useful devices. And not only household appliances are developing, but also industrial. What is inside the reflector telescope? How is the hydroelectric power station arranged? Why does the refrigerator cool the products, and the microwave heats up? How does the TV “catch” the channels? What happens, when we turn on the washing machine? The answers to these and other questions can be found on the pages of our book. At the same time, you will not only learn the history of the invention of useful machines and devices, but thanks to detailed drawings and diagrams you will look inside and understand how they are all arranged.