Stanza 1

The title “The Chambered Nautilus” refers to a sea creature that lives in the western Pacific and the Indian oceans and has a hard external shell, or exoskeleton. The creature lives in and is able to withdraw into the outermost compartment of its shell, which consists of sealed sections and is one of nature's best examples of a logarithmic spiral, one that grows at an exponential rate and appears to expand while it grows. Line 1 calls the nautilus a “ship of pearl,” which combines a comparison to a human-made sailing vessel with a description of the pearly finish of the nautilus shell. The speaker then notes that “poets feign,” or pretend, that the nautilus “Sails the unshadowed main,” or the wide-open waters.

Lines 3, 4, and 5 continue the conceit, or extended comparison, of the nautilus to a ship, creating an image of a “venturous,” or adventurous, wooden ship whose...