having immense wheels.

"No," replied Dr. Winstock. "They are mills for grinding grain."

"But what turns the wheels?"

"They are moored as you see them in the river, and the current turns
the wheels, which are very large, so as to gain power."

"That's a new idea to me," added Paul.

"I have seen just such in the Alabama River, in our own country,"
replied the surgeon.

"It is certainly a very good way to obtain the power."

The boat started, and soon made a landing at Biebrich, on the other
side of the river, where passengers from Frankfurt, Homburg, and
Wiesbaden usually take the steamers. As the Koenigin proceeded on her
way, a feeling of general disappointment pervaded the minds of the
party, who had not seen the river before.

"It does not compare with the Hudson," protested Paul.

"Wait, Paul!" said the doctor, with a smile.

"How long shall I wait?"

"Two hours. You must not be hasty in your judgment."

"What is this town on the right?" asked Grace.

"Eltville. Do you see the white building in the midst of the vineyards,
some distance down the river?" said the doctor, pointing to the shore.

"I see it."

"That is the chateau of Johannisberg, belonging to Prince Metternich,
formerly a celebrated prime minister of Austria. Those vineyards are
the most noted in the world. The famous Johannisberger wine is made
from these grapes. It sells here for five or six dollars a bottle,
where ordinary kinds can be bought for twenty cents, and even less. The
grapes are very precious, and are kept upon the vines till they are
nearly rotten. Those that fall off are picked up with a kind of fork,
so valuable are they deemed. Of the seventy acres contained in the
vineyard, only a small portion produces the best wine, which is not
found except in the cellars of kings and princes. This is Ruedesheim,
where the boat will make a landing," added Dr. Winstock, as the steamer
stopped her wheels. "A famous wine is also made here. It is said that
Charlemagne, seeing from his castle windows, near Mayence, how early
the snow disappeared from the heights below us, ordered vines from
France to be set out here; and from these vines is produced the noted
Ruedesheimer wine.

"What place is this?" inquired Paul, at a point where the course of the
river seemed to be obstructed by rocks and hills.

"Bingen on the Rhine," said the surgeon. "Here the waters of the river
are crowded in a narrow space. Look upon the hills around you