As in the case of the invention of the steamboat, the public has commonly lightly awarded the credit for each invention to some belated experimenter who, walking more firmly along a road which an earlier pioneer had broken, attained the goal that his predecessor had sought in vain.

So we find credit given almost universally to John Ericsson, the Swedish-born American, for the invention of the screw-propeller.

But as early as 1770 it was suggested by John Watt, and Stevens, the American inventor, actually gave a practical demonstration of its efficiency in 1804.
Ericsson perfected it in 1836, and soon thereafter the British began building steamships with screws instead of paddle-wheels.

For some reason, however, not easy now to conjecture, shipbuilders clung to the paddle-wheels for vessels making the transatlantic voyage, long after they were discarded on the shorter runs along the coasts of the British isles.
It so happened, too, that the first vessel to use the screw in transatlantic voyages, was also first iron ship built.

She was the "Great Britain," a ship of 3,000 tons, built for the Great Western Company at Bristol, England, and intended to eclipse any ship afloat.