The compass

The compass is the expedition’s most consequential surviving navigational instrument: after the storm on the Central Sea, its needle points in the wrong direction, concealing the travelers’ involuntary return toward their starting point and troubling Professor Hardwigg until the cause is finally identified. Its reversal makes the compass more than equipment. As the journey’s material record of direction, it exposes how a single physical disturbance can unsettle both geographical certainty and the Professor’s confidence in explanation.

Instrument and Expedition

The compass belongs to an expedition equipped to measure and negotiate an unfamiliar subterranean world. Its importance becomes especially clear when the raft is wrecked: most of the cargo has vanished, and the chronometer and compass are the only nautical and philosophical instruments left. The ladders and ropes have been reduced to a small remnant attached to the mast, while the picks, crowbar, hammer, and food are gone. In that depleted inventory, the compass remains one of the few tools by which the survivors can orient themselves.

The instrument’s practical role is inseparable from the expedition’s dependence on material equipment. The travelers have crossed a vast inland sea on a raft, and their understanding of where they are rests partly on observations and instruments rather than direct knowledge of the route. When the compass ceases to indicate the direction they expect, it does not merely give a bad reading: it makes the landscape harder to interpret and casts doubt on the account of their own progress.

The Reversal and Its Consequences

After the storm, the travelers return unexpectedly to the northern shore of the Central Sea. Rock formations resemble those near Port Gretchen, and the compass’s indications support the startling inference that they have been carried back toward their point of departure. Streams and cascades fall from the surrounding rock, and the apparent familiarity of the terrain offers a possible explanation for their position, though the changing profiles of cliffs and streams leave Henry Lawson uncertain.

Later, when boiling water and extreme heat accompany strange changes in the granite, Henry Lawson examines the compass as a last resource. The needle behaves wildly: it jumps from pole to pole, circles the dial, and abruptly runs back again. The malfunction appears amid a dangerous geological disturbance, making the instrument’s instability part of a larger breakdown in reliable orientation. The compass no longer settles the question of where the travelers are; its erratic motion intensifies it.

After the travelers emerge from the volcano, Henry Lawson imagines that they have crossed the globe and reached Asia, far from Europe. Professor Hardwigg immediately challenges this account by pointing to the compass: it had indicated that they were traveling north. Henry Lawson acknowledges the contradiction but has no explanation. The mismatch between the imagined route and the needle’s apparent testimony follows them out of the underground world rather than ending with their escape.

The Unsolved Instrument

The compass becomes a persistent problem for Professor Hardwigg. As the travelers proceed toward the port of Stromboli, he continues muttering that it had certainly marked north, a fact he cannot explain. The episode turns a tool meant to provide certainty into a challenge to the Professor’s authority as a learned interpreter of natural phenomena. Henry Lawson’s dry suggestion that they need not explain everything only sharpens the contrast between his acceptance of an unresolved fact and his uncle’s discomfort with it.

The mystery survives the return home. For six months the compass lies untouched, while Professor Hardwigg remains troubled by its inexplicable behavior. When Henry Lawson examines it again, he recognizes the clue that had been overlooked: after the expedition passed Cape Saknussemm, the needle had pointed south rather than north. The shift in the compass’s behavior gives the travelers’ apparently impossible directional history a coherent explanation, though the cause still needs to be supplied.

Explanation and Narrative Significance

Henry Lawson attributes the reversal to the storm on the Central Sea. A ball of fire during the storm magnetized the iron in the raft, turning the compass topsy-turvy. Professor Hardwigg accepts the explanation as a trick of electricity, and the discovery resolves the question that had continued to agitate him after the expedition was over. The instrument’s defect was not a random failure: the raft itself, their means of passage, had become part of the mechanism that altered the reading.

The delayed solution makes the compass a compact record of the expedition’s central conflict between observation and interpretation. During the return, it supplies evidence that the travelers cannot reconcile with their imagined route; after the journey, closer examination and recollection make that same evidence intelligible. Its needle has not simply misled them. The storm has changed the physical object, and the travelers have mistaken its new indication for a trustworthy guide. The compass thus preserves both the consequence of the storm and the limits of confidence in instruments when their material condition has changed.