to
within three or four miles. Furthermore, when the moon is shining, a
mariner, even without an instrument, will be able to make a pretty
accurate determination, if the moon is in sight."

"This is interesting information, and I would like to know how it is
done."

"Simply by noting how far the moon is from some fixed star. It is
difficult to explain this without making a drawing of the heavens or
drawing a map which shows the positions of the fixed stars, and the two
sketches (Figs. 13 and 14) that I have drawn out will, I hope, make it
clear to you. The first figure (13) is a map of the sky for the northern
hemisphere, and the second drawing (Fig. 14) of the southern hemisphere,
where we are.

[Illustration: _Northern Hemisphere. Fig. 13._]

"On the maps I have shown the fixed stars and named them, those of the
first magnitude being the largest, those of the second magnitude a
little smaller, and so on, but I have not by any means indicated all of
the second and third magnitude owing to their great number."

[Illustration: _Southern Hemisphere. Fig. 14._]

There had always been a secret grief in the hearts of Harry and George
at the loss of the boat at the mouth of South River, and the Professor
joined in their wish to recover it at the first opportunity. Harry again
alluded to it on this occasion, and it was decided that such a trip
would be a welcome change.

The trip could be made in the wagon, and by consent the four agreed to
undertake the journey and bring it back.

"I have often thought it might be done by taking the lifeboat," was
George's idea, "and we could fix it up there and sail it back."

"It does not seem to me that would be practical, because it is too much
damaged to repair in such a way as to make it safe for such a journey,
and if that plan should be adopted all of us should go, and we cannot
leave for the length of time necessary to repair it."

"Then we had better take the team. Do you think, Professor, we could
haul it back?"

"If you can load it there will be no difficulty in that particular."

It was decided to start the following morning, and a supply of
provisions was stored in the wagon, and before starting the Professor
made the following suggestions:

"When you get there the top must be removed--that is the bows and
covering----"

"Why, we haven't any covering to it now. We had to use it up for
clothing."

"I had forgotten all about that. I supposed the top had been ta