It is more like an episode than an illustration.

I quote it not only to show what I mean, but also for its power.

It is in Bk.

iv.
"As, shall I say, some Ethiop, past pursuit Of all enslavers, dips a shackled foot Burnt to the blood, into the drowsy black Enormous watercourse which guides him back To his own tribe again, where he is king; And laughs because he guesses, numbering The yellower poison-wattles on the pouch Of the first lizard wrested from its couch Under the slime (whose skin, the while, he strips To cure his nostril with, and festered lips, And eyeballs bloodshot through the desert-blast) That he has reached its boundary, at last May breathe;--thinks o'er enchantments of the South Sovereign to plague his enemies, their mouth, Eyes, nails, and hair; but, these enchantments tried In fancy, puts them soberly aside For truth, projects a cool return with friends, The likelihood of winning mere amends Ere long; thinks that, takes comfort silently, Then, from the river's brink, his wrongs and he, Hugging revenge close to their hearts, are soon Off-striding for the Mountains of the Moon." The best of these is where he illustrates the restless desire of a poet for the renewal of energy, for finding new worlds to sing.

The poet often seems to stop his work, to be satisfied.