Patrick Miller's first steamboat, 1788.

Engraving by W Annan of a lateral section of the double-hulled pleasure boat which featured the first marine steam engine. Patrick Miller (1731-1815), an Edinburgh banker, commisioned the mining engineer William Symington (1763-1831) to build a steam engine to power this experimental craft. The engine had two single-action cylinders, with separate condensers, which drove two paddle shafts by chains and ratchets, and propelled the steamboat on Dalswinton Loch, near Dumfries in Scotland, at five knots.