Read "The Sphinx of the Infinite" at The Eldritch Dark:
For the most part, I've been pretty impressed with all of the early poetry by Clark Ashton Smith (CAS) that I have read in my more-or-less chronological journey through the oeuvre. However, there have been a handful of clunkers along the way, and I think that "The Sphinx of the Infinite" is one of them.
My primary objection to this poem is that the central idea is not really developed, and CAS uses some fairly hesitant language ("Sees an eternal dawn upon the dark / Which is the curtain of impending sleep") which is not his usual style at all. I presume this poem was more of a draft than anything else, and not surprisingly was not published in CAS' lifetime.