200 Československých motoristických plaket z období 1922-1939

The author has compiled the history of the development and production of four-cylinder engines for motorcycles from the first preserved types. After a three-page introduction to the subject, there is the first of the structurally interesting motorcycles with a four-cylinder engine, where we also have a proud world first: the Laurin & Klement with an in-line four-cylinder engine made in Austria-Hungary. From a chronological perspective, various design directions are interesting, often avant-garde, but also some less fortunate ones, which were often limited by the possibilities of workshop processing. The theoretical idea of the designer was timeless, but the appropriate technology had not yet been produced. Detailed technical descriptions of another twenty-five structurally interesting motorcycles of often no longer existing production brands will certainly interest readers of all age groups.