manage the boat. If they did, it was difficult to understand why
they had not yet driven the boys away and taken charge.

There was another thought in Fred's mind that was perplexing. He
suspected that the supply of gasoline was running low. He had
neglected to have the tank filled the preceding night, believing
that he had a supply ample to carry them forward until they could
obtain more. Suppose the motor-boat should stop? What would the
men do? They might accuse him of deliberately stopping and in
that event he was aware that there might be serious trouble.
Indeed, he was still puzzled to understand why the men appeared
to be so contented. If they had been workers on the canal, or had
been employed by any of the boats why was it that they were free
this morning? He was aware that the little city of Rome could not
be far away.

If once he should be able to bring the Black Growler safely
within the borders of the city he was confident he would be able
to rid himself speedily of the men, whose presence with every
passing moment was becoming more difficult to bear.

He looked eagerly ahead for signs of the city. He was unable to
discover any, however, but his fears increased as he became more
positive that his supply of gasoline was low. If only it would
last a half-hour longer!

On either side of the canal was a level stretch of country and
near to the water no houses were to be seen. His friends had
taken seats on the deck forward. In low tones they conversed
among themselves, but Fred was too busy in his own task either to