The Seine River was the scene of many early experiments with steam navigation. The steamship has a long ancestry, dating back at least to 1783 when the Marquis de Jouffray d'Abbans steamed his little boat, the Pyroscaphe, across the Seine. Robert Fulton even exhibited one to Napoleon's regime. With the success of the steam engine by the 1820s, the Second Republic embarked on a series of navigation improvements to raise weirs and locks with which to deepen the navigation channel. By the 1860s improvements had changed the riverbed from low-lying sand banks and trickle to a series of cascading ponds with a depth of 6 and a half feet.