HMS 'Rattler' and HMS 'Alecto', 3 April 1845.

UNITED KINGDOM - NOVEMBER 15: HMS 'Rattler' and HMS 'Alecto', 3 April 1845. Lithograph. 'HM Steam Sloops 'Rattler' and 'Alecto' towing stern to stern for the purpose of testing the relative powers of the screw propeller and the paddle-wheel. The trial was made in the North Sea during a perfect calm on 3 April 1845, on which occasion the 'Rattler' towed the 'Alecto' sternforemost at the rate of two miles and eight tenths per hour; both vessels exerting their full power in opposite directions.' (Photo by Science & Society Picture Library/SSPL/Getty Images)