Vladimir Vladimirovich Ryumin in an entertaining way describes the methods of creating the simplest electrical devices that will allow readers to master the basics of electrical engineering. The book was written in the 1920s, but today it does not lose its relevance. Firstly, because the experiments and electrical appliances described in it underlie modern electrical engineering; and secondly, these experiments still remain important, as they can help to understand the principles of operation of modern electrical appliances. For a wide range of readers.