B give an angle with the
vertical line of the mast, which will enable you to determine how far
the ship is from any point."

"But I am still in the dark as to how, even if we have that distance, we
can thereby tell by triangulation, on the vessel, how far one point is
from another on the land."

[Illustration: _Fig. 7. Triangulation from a Vessel._]

"After the distance from the vessel to the point is determined, as I
have shown, then the length of the ship itself is used as the two points
to sight from, and the two lines thus projected, from the opposite ends
of the vessel, together with the line lengthwise along the ship, form a
triangle, the same as the triangle lines 1, 2, 3, in the sketch (Fig.
5)."

It might be well at this place to describe the equipment of the party as
it left the boat. The natives carried a plentiful supply of provisions.
Each had a gun, the best kind of breech loaders, and also a spear.

The natives love to handle spears better than anything else in the way
of a weapon, and each also had a knife, and some carried the inevitable
bolo, that primitive form of hatchet which is known all over the world
where steel or iron is available, and the people have arrived at such a
state that they are able to make metal articles.

John and the boys also carried guns, but the boys had revolvers, seven
shooters, not of large bore, but very convenient weapons, in close
quarters. Each carried also a knife, and belt to contain the cartridges
for the guns.

Harry carried a camera, which he had brought from the States, and George
had the field glass strapped across the shoulders. John felt that they
had a force large enough to make a fairly effective stand against a
pretty strong force of natives, the entire party counting, in this
instance, sixteen.

As they advanced into the interior, it was evident that they were
gradually ascending, so that at about six miles from the landing place
they reached the crest of the rising ground. Beyond, where the nature of
the ground permitted they saw clearly that the distance beyond had a
lower altitude than the place where they stood.

During this trip there was no evidence that the island was occupied, but
they saw the most amazing evidences of tropical fruits and trees.
Magnificent trees were in evidence everywhere, and the woods, besides
mahogany, and ebony, were of the most valuable character.

John noted all these things, but the boys were most interested in