Double-hulled pleasure steamboat, 1788.

Lithograph by C F Cheffins after a drawing by John C Bourne, after an oil painting by Alexander Nasmyth, of the boat which featured the first marine steam engine. Patrick Miller (1731-1815), an Edinburgh banker, commissioned 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, Scotland, at five knots. Symington's engine is now in the Science Museum. Illustration from 'A sketch of the origin and progress of steam navigation from authentic documents' by steam navigation pioneer Bennet Woodcroft (1803-1879) published in London in 1848.