The book describes the design of mechanical clocks and sets out the technology for their assembly in the scope of the program approved by the Main Directorate of Labor Reserves under the Council of Ministers of the USSR for training watchmakers-assemblers in technical schools. In the scope of the same program, brief information about alarms, stopwatches, pendulum clocks is reported; about self-winding watches with shockproof devices; about the clock with housing sealing.