On 19 June 1811 Friedrich Ludwig Jahn began public gymnastics in Berlin. This counts as the birth of the German gymnastics movement, Turnen. Jahn introduced many pieces of apparatus, among them the horizontal bar and the parallel bars. In 1816 he published, with Ernst Eiselen, Die deutsche Turnkunst, zur Einrichtung der Turnplätze dargestellt, German gymnastics, set out for the establishment of gymnastics grounds. According to German Wikipedia, the book came from practice for practice. It contains a model description of a gymnastics ground and its apparatus, the exercises, and the order and laws of gymnastics, down to the conduct and dress of gymnasts and teachers.