n within a month."

"By that time we will be on our way toward his section, and I hope we
shall have the opportunity of meeting him," responded John.

What required more attention than any part of the equipment, aside from
the ammunition, was the structure of the wagon. This had to be a fort
for them, and so arranged that it could be put up to meet an attack from
any quarter.

But this, unfortunately, left the yaks exposed to the assaults of the
spears and arrows, and John suggested a novel addition to the wagon
equipment.

"My idea is this: As we are all pretty strong, excepting the Professor,
to stand the march on foot, I would convert our wagon into a vehicle
which would carry the fort with us, and this fort, whenever we camped,
could be set up so that the yaks would be inside, and thus protected as
well as ourselves.

"To effect this the more readily, my plan would be to make three
sections of boards, in the form of a fence, each section to be six feet
high and ten feet long. These should be either folded together in the
middle lengthwise, so they could be nested together and swung below the
axles between the wheels, and set up to form a square at one side of the
wagon.

"One side of the wagon body could be made to be let down, so as to form
a protection below the body of the wagon. Within that enclosure the yaks
could be stationed, if we should be attacked, and for the purpose of
defense, four of us would be within the enclosure and two in the wagon
to protect it from that side.

[Illustration: _Fig. 33. The Portable Fort._]

"The sketch which I have made shows these features, in which you will
see (Fig. 33), the side boards (A) hinged along the middle line, as at
B. These would be held at the outer corners by posts C. In the sketch
the side board of the wagon body has been let down, so access can be
had to the wagon."

The plan, so ingeniously contrived, pleased the fancy of the boys.

"I imagine," said Harry, "this will be the first time people ever
carried their fort with them. It will be fun to meet the savages with
that kind of an outfit."

"You must not think, however," continued John, "that this is all we
shall need. We must take in the wagon sufficient food for the yaks to
withstand a siege, so that with our own provisions, guns and ammunition,
we shall have a pretty good load."

"How heavy will the three sections of fence weigh?"

"I estimate that, as we shall want the boards made of good