The enemy was advancing rapidly upon them and they had about given up in despair, when they saw a deer with her young step into the water and cross safely.  In full confidence that the instinct of the animal had guided her correctly, they followed and reached the south side of the Main safely.  The Saxons followed, but could not find the shallow place to cross, for there was no deer to guide them, and the city, dating from that time, was called Frankenfurt or Frankfort.”

This narrative was of deep interest to the boys, who gazed at the spot where Charlemagne had crossed more than eleven hundred years before.

“Did he live in Frankfort?” asked Paul.

“Yes, for even at that time the city was of some importance.  He built a fine palace which he named ‘Frankfort,’ and did much to improve the city and neighborhood.  He formed great hunting troops to destroy the wild animals which infested the forests and did much damage, bears, wolves, wild hogs and buffaloes making the forests dangerous to travelers.”

Now that they had heard this story of the river, they took keen interest in all that concerned it, especially the vessels upon its placid waters.

“They can carry great burdens,” remarked Fritz, “more than many horses could pull.”

“Suppose we have a question in arithmetic,” said Uncle Braun.  “I am sure that any one of you can solve it.  If one such vessel could carry thirty thousand hundredweight, how many horses would it take to draw that burden if two horses could draw fifty hundredweight, and how many wagons and drivers if each driver had two horses?”

Fritz was the ready reckoner of the three, and quickly answered, “Twelve hundred horses, six hundred wagons, and six hundred drivers.”

“Then you can see how much cheaper it is to have freight carried by sea.”

“What are those boards for reaching from the shore out over the water?” asked Paul.

“They are for those who wish to take a bath in the Main; and on these warm evenings it is very agreeable to have this refreshment to weary bodies.  Would you boys like to take a bath?”

“What would it cost?” asked Fritz.

“Eight cents.”

“Then I can’t take it.  I have no money.  Oh, my beautiful, bright gold—­”

“But would you take the bath if I pay for it?”

“Do you mean for Franz and Paul, too?”

“Yes, for all three.”

“Franz, do you and Paul take the bath, and Uncle Braun can give me the eight cents, which is just the same to him as if I took the bath.”

“Oh, Fritz, you ought to be ashamed of yourself!” exclaimed Paul.  “It was not money, but a bath that Uncle Braun offered us.”

Fritz had thought of this before Paul spoke, and his face had turned very red, and he could not raise his eyes to the face of his old friend.

But Uncle Braun laughed heartily at the different expressions upon the countenances of the three boys.