On April 8th 1838 the “Great Western”, the first steam-powered ship left Bristol docks for New York, arriving a mere 15 days later (at a time when sailing vessels took 30 days). In design “Great Western” derived from sailing vessels, having four masts and being capable of sailing, but also being powered by paddle wheels on either side.
The ship's designer, Isambard Kingdom Brunel (1806-59), went on in 1843 to design the “Great Britain”, the largest ship in the world at that time at 3270 tons displacement and 98m long, and the first ship with an iron hull and screw propulsion. (The ship retained six masts so it could move under sail when the winds were fair or should the engines fail.) Sceptics thought …
Editors. "First transatlantic crossing by steamship". The Literary Encyclopedia. First published 21 June 2005
[http://www.litencyc.com/php/stopics.php?rec=true&UID=1571, accessed 25 October 2016.]