In fact, Marco found that having such a secret as this upon his mind, was a source of great embarrassment and constraint, as he more than once came very near making some allusion inadvertently, which would have resulted in his exposure.

While speaking of boats, and oars, and paddles, and such subjects, he had to be continually upon his guard and to watch all his words.
[Illustration: PADDLING] They got into the boat and pushed out upon the water.

Forester taught Marco how to use the paddle.

He gave him his seat in the stern of the boat, and directed him to grasp the lower end of the handle with the other hand.

Then, by dipping the blade in the water and pushing the water back, the boat was propelled forward.