World’s First Monowheel?

From the website:

"In 1869 the craftsman Rousseau of Marseilles built this monocycle, which perches the cyclist on the inside of a 2 1/2 yards-high wheel. As there is no steering mechanism, it makes uncommon demands on the rider’s sense of balance." (from Galbiati & Ciravegna)

Note that this design actually has 2 wheels: it’s a wheel inside a wheel monowheel! Link