Exercise 1: sample answer

Macmillan: attributed. The story rests mainly on accounts written decades after the 1830s, and no surviving machine is certainly his (check). Michaux: closer to documented, because pedal machines were being sold from his Paris workshop in the early 1860s and the press reported them (check), though the personal credit for the invention is still disputed with Lallement and others. A careful statement credits the Paris trade with popularising the pedal velocipede and leaves the individual inventor open.