And some through wavering lights and shadows broke
Rolling a slumbrous sheet of foam below.
They saw the gleaming river seaward flow
From the inner land: far off, three mountain-tops,
Three silent pinnacles of aged snow,
Stood sunset-flushed: and, dewed with showery drops,
Up-clomb the shadowy pine above the woven copse.
—The Lotos-Eaters. Tennyson.
Often in the same poem the emotional changes are manifested in changes of rhythm. Observe this in the following lines:
Look! look! that livid flash!