Line 426:  Just behind (one oozy footstep) Frost

The reference is, of course, to Robert Frost (b. 1874).  The line displays one of those combinations of pun and metaphor at which our poet excels.  In the temperature charts of poetry high is low, and low high, so that the degree at which perfect crystallization occurs is above that of tepid facility.  This is what our modest poet says, in effect, respecting the atmosphere of his own fame.

Frost is the author of one of the greatest short poems in the English language, a poem that every American boy knows by heart, about the wintry woods, and the dreary dusk, and the little horsebells of gentle remonstration in the dull darkening air, and that prodigious and poignant end—two closing lines identical in every syllable, but one personal and physical, and the other metaphysical and universal.  I dare not quote from memory lest I displace one small precious word.

With all his excellent gifts, John Shade could never make his snowflakes settle that way.