The exhaust side of the Dürkopp four-cylinder Bicycle Engine, each cylinder measuring 52 mm. x 60 m.m. This engine has a self- contained magneto, built up with the flywheel. An illustration and description of this magneto device appeared in The Motor Cycle for January 23rd, 1905, page 81.

Stanley Show 1905 (Part 3)
Durkopp of Bielefeld