sentences:  His father, Johann Buschmann, was a passementier, who later started to fix musical Instruments and in 1816 developed the uranion later called terpodion, a friction instrument played with a piano-like keyboard, based on the same principle as the glass harmonica.From 1819 Johann took Friedrich with him on his frequent journeys.In the first half of 1821 Johann Buschmann travelled to London, accompanied by his son Friedrich, and agreed to a £1,000 contract with a Mr. Löschmann besides taking other orders for terpodions.