The author of the book is a specialist watchmaker with 40 years of practical experience. The second edition of the book, significantly revised, is published in four issues. The first issue is devoted to the basics of watchmaking theory; it contains brief information from mechanics, data on the design of the pendulum, balance, descents (moves), wheel mechanism and the gearings used in it. The book is designed for watchmaking specialists and watch factory workers; it can also be used as a teaching aid for students of technical schools and FZU.