You are reading this book in your room and don’t even notice how many useful machines surround you. Vacuum cleaner, refrigerator, microwave oven, coffee grinder, mixer, washing machine, air conditioner... It’s difficult to list everything. And every invention has its own story. How these wonderful human assistants were invented, is it true that a vacuum cleaner used to be horse-drawn, when the first washing machine appeared and whether Tsar Alexander I had a refrigerator, the author of this book, Vladimir Malov, will tell you. For primary school age. In PDF A4 format The publishing layout of the book has been preserved.