l. Apollo, the bull of their herd. His absence. The wild bull
charging George. Stampede of the herd. George carried with them.
Appearance of Apollo. Engaging in combat. Apollo the stronger.
Reappearance of George. Return of the cows. Apollo the victor.
Finding a brand mark on the wild bull. Inventory of their stock.
Work in tanning vats. The flash of Harry's gun in the distance.
Explanation of the difference in time between the flash and report.
"Sound" or "noise." Vibrations. Light. The locomotive whistle
explained.

IX. EXCITING EXPERIENCES WITH THE BOATS

Health on the island. Illness of Harry. Fever. Determining
temperature. Making a thermometer. Substitutes for glass and
mercury. How Fahrenheit scale is determined. Centigrade scale.
Testing the thermometer. Determining fever. Danger point. Why a
coiled pipe tries to straighten out under pressure. Medicine for
fever. Rains and rising Cataract River. Decision to explore sea
coast to the east. Yoking up the yaks. Gathering samples of plants
and flowers. The beach. Following the shore line. Discovering the
boat which had disappeared from the Falls in South River.
Surprising find of strange oars and unfamiliar rope in the boat.
Harry and George decide to sail the boat around the cliff point to
the Cataract River. The Professor takes the team home. Sighting an
object on the cliffs. Going ashore at the foot of the cliffs for an
examination. Ascending the cliffs. Discovering the wrecked remains
of their life-boat. Consternation when their boat is washed away
from the shore. Getting the wreck of the life-boat down to the
water. The watching and waiting Professor. The boys launch the
life-boat and float to the mainland. Meeting the Professor.
Explanations.

X. THE BIRTHDAY PARTY AND THE SURPRISE

Theory that their island is near some other inhabited island. The
mysterious occurrences of the fire in the forest; the lights across
the river. The disappearance of their boat. The removal of the
flagpole and flag; the arrows; the hole in the hillside; the
finding of the boat with unfamiliar oars and rope on it. Conclude
to make another boat. Unsanitary arrangement of their kitchen.
Purifying means employed. Different purifying agents. Primary
electric battery. The cell; how made. The electrodes. Clay.