In this passage, the author utilizes both metaphor and personification to depict the sun casting its light over the volcano. This poignant moment happens shortly before the Professor, his nephew, and Hans go underground. Axel feels a sense of serenity, experiencing a moment of calm before the approaching intensity of the underground adventure:
The sun at his lowest point gilding the sleeping island at my feet with his pale rays.
Personification is centrally at play in this passage. Verne describes the light dying down over Iceland as if it were an action the sun knowingly takes. It is ascribed agency as it performs the human action of "gilding" the land. When something is “gilded,” a thin layer of gold leaf is applied very delicately with glue and a brush. The sun’s action here implies a purposeful, almost tender act of embellishing the island with its light before the party leaves its sight. This personification makes the sun seem benevolent, as if it is intentionally gracing everything above ground with soothing golden illumination one last time.
The metaphor of gilding also has a second implied meaning: when something is gilded, its golden surface is extremely thin and delicate. Gilding just makes things look golden but doesn’t substantially increase their value. The sun can only cover the surface of the island with its “pale rays.” Verne uses the verb “to gild” metaphorically to convey the way the sun's light gives the scene a tranquil, pale beauty. However, it also invokes the fragility of the “gilding” process. In this description, the reader is reminded that the sun can only touch the “outside” of the world. It can’t “gild” what’s under the ground. When they enter Saknussemm’s secret passage, Axel and his friends will pass beyond the thin layer of its reach.