Clark Ashton Smith (CAS) wrote two poems with the title "Somnus", one of which was included in his omnibus Selected Poems (1971). Under consideration here is the other one, and as it was unpublished in his lifetime, here's the full text:
The flowing silence of Lethe
Thro gulfs of more than Erebean gloom--
Beyond the fiery troubling of the stars
And moons made pale with travail
Or the loud seas exulting to the sun--
The lapse of oblivion--of night utterness.
The thunder-driven chariots of storm.
The sun, which in the golden lamp of noon,
Whose hours elude the groping light--
Lost in the hollow silence
Or dimmer than mirages of the moon--
In gloom declivous as to under-gloom--
Less than the foam of Lethe seem the worlds--
Softer than the fall of lotos-petals.
The line "The lapse of oblivion--of night utterness" is worth the price of admission by itself - who but CAS could write such a line?
This poem has an elusive nature, never quite establishing a concrete central image or scenario. Nonetheless, CAS has created a very rich and rhythmic verse, with words using the long oo sound (gloom, moon, noon, etc) providing a rough pattern that draws the reader forward.
For an unpublished poem, this one is impressive. Although it feels more like a poetic sketch than a fully-formed sonnet, it nonetheless exhibits CAS' unique artistic voice, and its experimental nature makes it all the more interesting.