Benin issued in 1995 a set of stamps with watercraft on it, the 40f stamp depict a paddelsteamer without a name.
The book, Powered Ships the beginnings gives on page 30 the same paddlesteamer, with the caption Miller and Symington’s experimental steamboat on Loch Dalswinton, 1788.
Patrick Miller (1731-1815) from Dalswinton a banker invented in 1787 a double-hulled boat, with the intention to use it on the Firth of Forth by men working a capstan, which drove the paddles on each side. The men al soon became exhausted and the boat was not a success.
He spent £30.000 on all his abortive experiments before he came in touch with the Scottish engineer William Symington (1763-1831).
Symington built a steam engine, with two single-action cylinders, with separate condensers, which drove two paddle shafts by chains and ratchets to power the double-hulled craft of Miller. The paddlewheels were fitted between the two hulls in the center of the craft, one before the engine the other behind.
The engine was mounted in an oak frame and set up on the deck of a craft.
The dimensions of the craft were 25 feet long and 7 feet beam.
14 October 1788 the first trial was made on Loch Dalswinton near Dumfries in Scotland.
She made a speed of 5 miles on the loch and was considered an outstanding success, after a few more runs on the loch the engine was taken out of the craft, and a new stronger engine was built in, the new engine did give the boat a speed of 7 miles.
The old engine was put in the garden of Mr. Miller as an ornamental curiosity.
Then Mr. Miller got out of pocket, or he had put enough money in it, and he abandoned the project.
Benin 1995 40f sg 1285, scott 748
Source: some web-sites. Powered Ships, the beginnings by Richard Armstrong.