Metaphor in The Chambered Nautilus

In a continuation of the metaphor of the shell’s chambers as mansions that mark one’s progress, Holmes swaps out “mansions” for “temples,” explicitly signalling the spiritual nature of the progress. These ever larger and “nobler” temples, however, “shut thee from heaven,” suggesting that the temples are ultimately limiting constructs, preventing the nautilus from reaching the numinous reality it seeks.

The final stanza represents the message of the nautilus, as recorded—perhaps imaginatively—by the speaker. Addressing “my soul,” the nautilus says, “build thee more stately mansions.” On one level, this is an extension of the shell-as-house metaphor, referring to the series of “mansions” the nautilus builds for itself. On an allusive level, this draws on the Bible, specifically John 14:2, in which Jesus says, “In my Father's house are many mansions.” At this level, the mansions are a spiritual, metaphysical construction, perhaps representing the layers of experience and development that accrue over the course of one’s life.

The phrase “deep caves of thought” applies two new metaphors to the nautilus shell. The first is that of “deep caves,” an apt image for the receding chambers within the spiraling shell. The other is that of a brain or, more conceptually, a mind—in either case, the source of “thought.” The metaphors are nested, for “deep caves” also serves as a vehicle for the tenor of “thought”—both of which, in turn, serve as a vehicle for the nautilus itself as it dispenses its treasured wisdom to the speaker.

This stanza describes the process by which the nautilus matures, creates new shell chambers, and moves its organs. Holmes employs the intuitive metaphor of moving houses, as if the nautilus were changing dwellings on a yearly basis—an accurate characterization.

At this point in the poem, the speaker is presumably peering inside the shell of the now-lifeless nautilus. The metaphor of the shell as a “sunless crypt” conveys both that the nautilus died within its own shell and that the opening of the shell represents a confrontation with a heretofore unglimpsed mystery, sunlight serving as an implicit metaphor for knowledge.

The image of the the nautilus shell as an “irised ceiling” is a double metaphor, comparing the shell to both an eye and a house. The eye metaphor touches on the literal reality of the nautilus shell, which encircles the nautilus’s eyehole in the way an iris encircles a pupil.

The “webs of living gauze” refer to the method by which the chambered nautilus creates its shell, which involves the continual application of layers of aragonite. The metaphor of “gauze,” a thin linen fabric, suggests the gauzy translucence of the pearl shell. Having crashed ashore and died, the nautilus “no more unfurl[s]” its layers of shell.

Here Holmes introduces an important extended metaphor: that of the chambered nautilus as a ship at sea. With its buoyant, concave structure, the shell of the nautilus resembles the hull of a ship. However, to say it is a ship “of pearl” is not a metaphor. Like its fellow molluscs, the chambered nautilus fashions its shell out of nacre, a material better known as mother of pearl. With its pearlescent gleam and helical architecture, the nautilus shell has long stirred the curiosities of artists and collectors alike.