this enterprise was repeated, the next steam
voyage being in 1831, when the Royal William crossed from Quebec to
England. She used coal for fuel, having utilized her entire hold to
store enough for the voyage. The Savannah had burned pitch-pine under
her engines, for in America wood was long used as fuel for steam-making
purposes. As regards this matter, the problem of fuel was of leading
importance, and it was seriously questioned if a ship could be built to
cross the Atlantic depending solely upon steam power. Steam-engines in
those days were not very economical, needing four or five times as much
fuel for the same power as the engines of recent date.

It was not until 1838 that the problem was solved. On April 23d of that
year a most significant event took place. Two steamships dropped anchor
in the harbor of New York, the Sirius and the Great Western. Both of
these had made the entire voyage under steam, the Sirius, in eighteen
and a half and the Great Western in fourteen and a half days, measuring
from Queenstown. The Sirius had taken on board 450 tons of coal, but all
this was burned by the time Sandy Hook was reached, and she had to burn
her spare spars and forty-three barrels of rosin to make her way up the
bay. The Great Western, on the contrary, had coal to spare.

Two innovations in shipbuilding were soon introduced. These were the
building of iron instead of wooden ships and the replacing of the paddle
wheel by the screw propeller. The screw-propeller was first successfully
introduced by the famous Swede, John Ericsson, in 1835. His propeller
was tried in a small vessel, forty-five feet long and eight wide, which
was driven at the rate of ten miles an hour, and towed a large packet
ship at fair speed. Ericsson, not being appreciated in England, came
to America to experiment. Other inventors were also at work in the same
line.

Their experiments attracted the attention of Isambard Brunel, one of
the greatest engineers of the period, who was then engaged in building
a large paddle-wheel steamer, the Great Britain. Appreciating the new
idea, he had the engines of the new ship changed and a screw propeller
introduced. This ship, a great one for the time, 322 feet long and of
3443 tons, made her first voyage from Liverpool to New York in 1845, her
average speed being 12 1/4 knots an hour, the length of the voyage 14
days and 21 hours.

By the date named the crossing of the Atlantic by steamships had become
a